Sam Feltham’s Second Overeating Experiment

Back in June, I wrote a post about Sam Feltham’s n=1 experiment in which he consumed more than 5,000 calories per day of low-carb/high-fat foods for 21 days.  In a post on his Smash The Fat blog introducing that experiment, he spelled out exactly what he would eating:  lots of meats, eggs, greens and nuts.  The macronutrient breakdown on a typical day looked like this:

Calories:  5,794
Protein:  333.2
Fat:  461.42
Carbohydrates:  85.2g

Feltham estimated his daily calorie expenditure to be around 3,128.  (He’s an active cyclist.)  So according to the simple calories-in/calories-out theory, he should have gained nearly 13 pounds in 21 days.  But he didn’t.  As he reported at the end of the 21 days, he gained less than three pounds – while losing an inch around his waist.  In other words, he gained a bit of lean mass but apparently didn’t get any fatter.

I wouldn’t suggest people who’ve battled a weight problem repeat that experiment, of course.  If you check the pictures on his blog, you’ll see that Feltham looks like a naturally lean guy.  His body probably resists gaining fat.

Ahhh, but what if he consumed more than 5,000 calories per day on a diet high in refined carbohydrates?  Would the hormonal effects of all those excess carbohydrates overcome his natural resistance to getting fatter?

In a word:  Yup.

Feltham recently completed yet another n=1 experiment that lasted 21 days.  This time the diet looked like something Morgan Spurlock would try (assuming he could eat all these foods at McDonald’s while pretending to only consume three meals per day) … cereals, breads, jam, pasta, desserts and sodas.  Here’s the breakdown:

Calories:  5,793
Protein:  188.65
Fat:  140.8
Carbohydrates:  892.7

Wow.  My glucose is rising just looking at those figures.   Let’s look at Feltham’s results from his blog:

As it was the last day I also weighed myself this evening at 97.3kg, giving me a mean for day 21 at 96.8kg, which is a massive +7.1kg up from the start and +0.1kg above the calorie formula on a 53,872 k/cal surplus.

So he gained almost 16 pounds.  And it wasn’t lean tissue this time, either.  He also gained three inches around his waist.  (He had small waist to begin with, so nobody will be asking him to wear the Santa suit at this year’s holiday party.)

What’s interesting to me is that on the high-carb overeating experiment, the calorie equation held up.  Unlike with his LCHF diet, Feltham did, in fact, gain a fraction more than one pound for every 3,500 extra calories he consumed.

I’d say the same about Morgan Spurlock’s sugar-fest month at McDonald’s.  Spurlock gained 24 pounds in 30 days, which means he was probably overeating by around 2,800 calories per day.  (We of course don’t know for sure, since he won’t show anyone his food log.  But his nutritionist cautioned him twice in Super Size Me that he was eating more than 5,000 calories per day.  And unlike Feltham, who continued his exercise routine during his experiment, Spurlock intentionally moved as little as possible.)

As I mentioned in my post about Feltham’s first experiment, the calorie freaks immediately tried to explain away his inability to gain more than a few pounds on 5,200 daily calories of LCHF foods by insisting he must have a super-fast metabolism.  Funny how that super-fast metabolism didn’t help him when he switched to a diet full of refined carbohydrates.

By the way, Feltham has already gone back to a LCHF diet (which he’s calling his rehab diet) to undo the damage.  He’s 10 days into a diet consisting of meats, greens, butter and nuts.  His average daily intake is 3,622 calories, 313 grams of fat, 170 grams of protein and 34.38 grams of carbohydrates.

He’s lost just over nine pounds as a result.  A good chunk of that is likely water weight, but I suspect he’ll be back to his original weight and body-fat percentage soon enough.


74 thoughts on “Sam Feltham’s Second Overeating Experiment

  1. Craig

    This post following your one about Tom Hank’s weight fluctuation for movies reminded me of when actor Rob McElhenney quickly gained 50 pounds a few years ago for a season on It’s Always Sunny in Philadelphia where his character Mac got really fat. In interviews he said he ate 5,000 calories a day spread across five 1,000 calories meals. His go-to meal was rice, chicken and vegetables. When his weight gain stalled his nutritionist advising his weight gain had him to start exercising since he wasn’t going to burn the fat with that diet so adding muscle under the fat would just add additional weight and bulk.

    So: Spread eating out through five meals a day. Eat lots of rice, vegetables and lean meat. Exercise regularly. Does his program for going from lean to obese in a few months sound similar to any advice you’ve heard for people wanting to lose weight?

    Indeed it does … well, minus the 1,000-calorie meals.

  2. Gerard Pinzone

    There’s another thing to consider about the rehab diet phase… The reason he’s consuming 3,622 calories is because according to the calorie formula, he shouldn’t be losing weight on that diet. Obviously, he is. The last nail in the coffin is when he attempts the 5,000 calorie “Starch Solution” diet.

  3. JasonG

    How would the CICO supporters rationalize away these results?

    Give them time. They’ll come up with some rationalization.

  4. Buzz

    “A good chunk of that is likely water weight”

    Thank you, Tom, for being the only person writing about this that has mentioned water weight. We all know that most people will retain quite a bit of water on a high carb diet.

    I would have liked to have seen body fat testing to find out how much actual fat he put on during both phases. That would have been the best comparison.

    1. Firebird7478

      I told Sam on the first few days on the diet that he would gain water weight from the carbs, not fat, which he knew and understood to be the case, so it would reason that the first few pounds lost would also be water.

      Bodybuilders do this right before a competition. They go zero carbs and to lean out even further, drink very little liquids the day before and of the competition.

  5. TJ Huber

    This is not only fascinating, but it also makes wonderful reading. How I wish it would work for me. On the average, I consume less than 35 gm of carbs a day and about 2600 calories total. I’m 67, type II diabetic and weigh 255 lbs. I just can’t lose from there (I am down from 315 over several years). Looks like I am stuck. The fact that cooking is my hobby probably doesn’t help, but it guarantees that my food intake is charted accurately. If Feltham can bottle what makes him tick, I’ll be the first in line to buy it.
    P.S.: I hope you got some rain on the farm, we didn’t get nearly enough.

    If anything, we got more rain this year than we needed.

    Feltham appears to have the lean-guy body type. He almost certainly sheds body fat faster than those of us who battled weight problems.

    1. Lori

      @TJ, my mom is T2 and 84 years old. She’s finally starting to lose weight now that she’s on metformin and has been able to reduce her insulin quite a bit.

    2. Nads

      TJ, even though I believe in the LCHF concept, 2600 is more a maintenance calorie level for a guy your size and age who possibly isn’t moving around much. Gary Taubes admits it is still about calories in and calories out, but it’s more why are there more calories coming in and out. (Watch the youtube exerpt from a lecture of his, I think it is called Gary Taubes explains the law of thermodynamics, and he talks about people coming in and out of a room).

      Sam Feltham will be doing the McDougall type healthy starches challenge in January. Can’t wait!

      1. david

        Any diet this Smash the Fat guy does or would do is worthless , he has no consistency. The first diet he measured cholesterol , the second he didnt. Nuts work a lot differently than regular fat in meats, nuts have fiber . Any way enjoy the roller coaster of fat and animal eating. We will see how the main guys fare eventually. To start Atkins was a big disappointment with his obesity and Cardiovascualar disease. After eating all those healthy fats/meats and not eating the ugly carbs he dug his own tomb.
        Will see Dr Barry Sears, Dr Loren Cordain, Sally Fallon, Jimmy Moore even though he is a marathon walker, pseudoresearcher Gary Taubes, Dr William Davis, Only the time would tell the real story about these fat guys.
        So according to this moron Sam Feltham this guys should be obese eating only carbs,
        Dr McDougall, Dr Esselstyn, Dr Neal Barnard, Dr Campbell, So ? these guy are in reality eating a LCHF diet? Use your brain please.

        1. Tom Naughton Post author

          Who said McDougall and Bernard are eating LCHF?

          Atkins dug his own tomb? You’re aware that he died after slipping on ice and cracking his skull on a concrete curb, aren’t you? Are you suggesting his low-carb diet caused the fall?

          If you believe Atkins was obese, that means you fell for the nonsense put out by PETA. His weight when he was taken to the hospital was 190. (His widow later released the medical records to prove what shitheels the PETA people are.) Doctors gave him a steroid to try to save his life while he was still in a coma. The steroid caused him to balloon up. That’s where the “obese” nonsense came from. The PETA people of course know this, but they’re not interested in facts. They’re interested in pushing their agenda.

          So yes, “use your brain please” is good advice, and I’d suggest you follow it.

        2. Roy Walker

          Maybe some people respond well to a vegetarian diet, some people to high carbs and low fat, and some to high protein and carbs, and still otheres respond to high fat medium protein and low carb. Who really knows for sure. Just my thoughts anyway.

  6. Beowulf

    Any sense for what the “experts” have said about his experiments? Or are they still in the “if we ignore them these contradictions will go away” phase?

    On a different note, if he does a third n=1 experiment with overfeeding, it would be interesting to see what happens with a high carb/low fat whole foods paleo diet. I imagine there would still be weight gain, but I’m curious as to whether his body would respond differently to a whole-food diet with lots of sweet potatoes and fruit vs. a highly processed diet heavy on the grains.

    I would suspect the results from gains and sugars would be worse.

  7. Justin B

    I believe you may have the original LCHF calorie count wrong. It was apples to apples, according to Sam. The calorie count of the first experiment was actually 1 calorie higher than the new experiment, or 5,794 calories. He joked that this was to “give the high carb diet a fighting chance”.

    Ahh, okay. He has a typo on his introductory page, which is where I got the figure. On other pages, he cites the same figures as you. So it was apples to apples. I’ll fix the text, thanks.

  8. Btown

    I have followed your work since 2010. Been a skeptic and trial and error with trying lchf. I’m curious as to wonder if you think maybe everyone’s bodies are different? For example…fat may harm me but it won’t harm you? That kind of analogy. I do carbnite (lchf during the day and a carb meal at night) and I wonder if it probably isn’t ideal?

    Yes, I believe we’re all different. Chris Gardner’s study demonstrated that people who are insulin-resistant do much better on a low-carb diet, while people who aren’t insulin-resistant lose weight at the same rate on pretty much any diet.

    As for whether or not a carb meal per day is harming you, the only way to figure that out is to check the effects on your glucose, fasting triglycerides, etc. I’d say it would also depend on what kind of carbs you include in that meal. A sweet potato and a piece of bread aren’t the same.

    1. Btown

      I get it. But does it mean since it works differently for people, cholesterol will harm me but not you?

      Is the only way to tell I’m insulin resistant or sensitive to carbs by weight gain? I def know when I eat carbs my heart pounds and I feel awful…..especially sugar…

      There are people who don’t properly clear cholesterol from their systems, yes.

      There are lab tests to determine your insulin levels and ability to tolerate glucose. But if you feel awful after sugar and other refined carbs, you already know to listen to your body.

  9. eddie watts

    good stuff. i wish he’d made it so that
    carbs were not sugar based
    protein was same as LCHF diet

    that said on it’s own it is good for disputing the CICO idea.
    (i’m aware someone eating LCHF would almost definitely eat more protein than someone on a more “balanced” diet. how i hate that word!)

  10. Toni

    This is such a great reflection of my own personal experience. Three months ago I was 175 lbs. According to the calorie calculators out there, my maintenance level of calories (based on weight, height, age, gender, and activity level) was about 1800 cal per day, about 1300 – 1500 cal per day to lose 0.5-1 per week. I was already struggling at 1800 cal per day on my former low fat, high carb diet, and just couldn’t see making any more cuts (I had stopped drinking soda years ago, was eating fat free dairy, lean meat, plenty of fruits and veggies, and the requisite crap-ton of hearthealthywholegrains – and of course, I was starving).

    Then I saw your documentary.

    I decided to give low carb/high fat a try for 6 weeks. I logged my food to make sure I was hitting my macros properly (50-60% fat, 20-30% protein, and 20% or less of my calories coming from carbs). Logging my food also revealed that my calorie intake remained at an average of 1800 per day (and I wasn’t hungry anymore – yay!). In that six weeks, despite what the calorie calculators said would happen (that I should have maintained my 175 lb weight), I lost 12 lbs and dropped a dress size. But that was the least of the benefits – no more hunger, no more hypoglycemia when a meal is delayed, no more eczema, tons more energy, more consistent energy throughout the day, etc. But I’m preaching to the choir here…

    As of today (three months into this way of eating) I’ve dropped 21 lbs total. Even if you subtract out the 5-6 lbs of water/glycogen I lost in the first week, that still leaves me losing just over a pound a week, eating at a level that I was told would be “maintenance” on a low fat diet. And when I calculate my new maintenance level (based on my new weight), it’s dropped to about 1700 cal/day. And I’m still eating 1800 per day. And still losing between 0.5 and 1 lb per week. Funny that.

    I wanted to take the opportunity to thank you for explaining low carb diets in a way that makes sense, and for making me rethink what I was doing before. I had always been afraid to try a low carb diet because of the negative press they get, but seeing all the conventional wisdom critiqued and finding all the information on this website helped me discover something that really works for me, and is much more sustainable than eating 1400 cal/day could ever be! For the first time in my adult life, I believe I can get under 150 lbs, and into single digit dress sizes, without starving or compulsively exercising. I can’t thank you enough for opening my eyes to something new!

    That’s what makes this diet such a godsend for so many people: the ability to lose weight without being hungry. Going through life hungry all the time is no way to live.

  11. Ondrej

    Sam the sham’s jokexperiment proves that a calorie is not a calorie because all of those metabolic ward studies that demonstrate time and again that a calorie is indeed a calorie are no substitute for free-living studies with questionable accountability, or especially the “real world” example of a skinny dude running fatloss bootcamps where we have only his word that he even did what he claims, and he can’t even be bothered to verify what his weight maintaining caloric intake is to begin with.

    Those metabolic ward studies demonstrate that if you semi-starve people, the macronutrient content makes little difference. No surprise there; a semi-starvation diet will automatically lower insulin and put the body in a state where it sucks up every available calorie for energy.

    Feltham’s experiment, on other hand, demonstrates what many of us have discovered for ourselves: We are much more resistant to accumulating body fat on a LCHF diet. As I’ve mentioned in my cruise reports, I ate three or four large meals per day for a week during the cruises, very high calorie counts, but didn’t gain an ounce.

    If you prefer to believe that Feltham is lying so you can maintain your current beliefs about calories, be my guest. I have no interest in trying to change a closed mind.

    1. Ondrej

      “Those metabolic ward studies demonstrate that if you semi-starve people”

      Semi-starve? Are you serious? evidently you are not well familiarized with MWS.

      Here is one and nobody was “semi-starved”:

      “Feltham’s experiment, on other hand, demonstrates what many of us have discovered for ourselves: We are much more resistant to accumulating body fat on a LCHF diet.”

      There is not a single biochemistry textbook in the world that supports this statement. Fat you eat goes straight to fat body stores. It doesn’t magically vanish into thin air.

      “If you prefer to believe that Feltham is lying so you can maintain your current beliefs about calories”

      And you prefer to have faith in Sam but not on controlled scientific research.

      I’m surprised you’ve adopted a position contrary to your own “Science For
      Smart People.”

      Your faith will not move mountains.

      The article you quoted was about a maintenance diet. It had zip to do with whether or not we are more resistant to gaining body fat on one diet versus another when eating a high number of calories. The professor quoted also made a statement that simply isn’t true, or at least not complete: “calories leave the system when food is used to fuel the body.” Really? Calories can only be used up as fuel? Hardly. Calories can “leave the system” by raising body temperature, by repairing tissue or building new tissue, by being used up in the conversion to energy (1/3 of the calories in protein are lost in the conversion to glucose), or by being excreted without being fully digested. Nothing Sam Feltham is claiming (or any of us is claiming) requires calories to disappear into thin air.

      There’s nothing contrary to the positions in “Science For Smart People” in believing Feltham is telling the truth about his experiments. I’ve experienced exactly what he experienced myself, as have many, many other people I’ve talked to. So it’s not faith, it’s personal experience. You are putting yourself in the rather stupid position of trying to tell all of us that we didn’t experience what we did, in fact, experience.

      Like I said, if you prefer to believe it’s all about calories and that macronutrients make no difference, be my guest. But if you believe you’re going to persuade those of us who have personally experienced dramatic results by adopting a LCHF diet, you’re flattering yourself in the extreme. Trust me, you’re not brilliant enough to come up with the magic argument that will convince us to ignore what we’ve experienced for ourselves. So apparently you’re arguing for the sake of argument.

      1. Dave

        Ondrej, it’s very simple. Really. Do your own 5000 calorie per day ‘experiment’ in the diet of your choice and post the results on your own blog or YouTube. It wouldn’t hurt to do a ketogenic diet, a SAD, and 50 bananas a day. Whatever. It won’t be ‘scientific,’ but you can prove to the world that your body works like a perfect physics equation.

        Personally, I’m looking forward to Sam’s next experiment very much. I think he will have somewhat different results on a diet much lower in fructose. He will be attempting what Peter at the Hyperlipid blog calls ‘taterism.’ It should change his body from physiologic insulin resistance (glucose conservation necessary on a HFLC diet) to a very insulin sensitive metabolism. He may even see some health benefits in the short term. The major confounding factor would be his body fat stores from his current way of eating providing a ‘cushion’ so to speak for the duration of his experiment. It would be nice to see him continue the time on a ‘tater based diet longer just to see what happens, say after 90 days.

      2. Ondrej

        I’m sorry sir but the article was not just about a maintenance diet.

        Had you read the article and the study, you would have seen that it was proven scientifically that at a maintenance diet people do not lose weight if they go low carb/high fat.

        If you contend that you will not gain weight eating excess calories low carb/high fat, then by definition, you will lose weight eating low carb/high fat at maintenance level calories.

        The burden of proof of Sam’s veracity is on him not me. I did not make outlandish claims refuted by CRTs.

        However, Sam can redeem himself easily. He can undergo a lie detector test. If he passes, he could say that he is an anomaly of science. Funding should not be a problem. NuSI’s war chest can afford one for every low carber in the world.

        And let’s get something perfectly clear. I’m not trying to convince you or anyone to eat a certain way. I don’t care it you or anybody wants to eat LCHF. As far as I’m concerned you can eat a barrel of lard everyday, if you so desire.

        I’m only presenting facts.

        I did read the article. It was about a maintenance diet, period. They didn’t have people consume 5,000+ calories per day on different diets to see what would happen, so the article has zero bearing on Feltham’s experiment.

        “If you contend that you will not gain weight eating excess calories low carb/high fat, then by definition, you will lose weight eating low carb/high fat at maintenance level calories.”

        That is a completely illogical statement. What the body decides to do with more calories than it needs isn’t the same as what the body decides to do with exactly the number of calories it needs.

        Feltham kept detailed data and reported his results. That’s what researchers did in the studies you prefer to believe as well. So by your logic (to abuse the word “logic”), I can declare that those researchers are probably lying, that the burden of proof is on them not me, and that nobody should believe them unless they submit to a lie-detector test.

        What CRTs refute Feltham’s results? Send me links to all the metabolic ward studies of what happens when lean, healthy young men consume 5,7000 calories per day of either a high-carb or low-carb diet. Surely you must have read several of them by now, since you keep insisting his results are made up.

        And if you do find any such studies, please send me the results of the lie-detector tests the researchers took so we can believe their data.

        1. Toni

          “If you contend that you will not gain weight eating excess calories low carb/high fat, then by definition, you will lose weight eating low carb/high fat at maintenance level calories.”

          Ondrej, that’s precisely what Ive been doing for the last three months. According to the same formula Sam is using, my maintenance level caloric intake (at my old 175 lb weight) is about 1800 cal per day. And I did, indeed, maintain that weight while adhering to a low fat, high carb, 1800 cal/day diet. Switching to high fat, low carb allowed me to eat the same number of calories and lose 21 lbs in the last 3 months.

          Let me say that again: I have been eating at (and currently *above*) my “maintenance” level, and I am *losing* weight. Why am I losing weight eating the same number of calories as before? IDK. I’m not a scientist, nor am I doctor. I suspect, given my family history (lots of type II diabetics, heart disease, Alzheimer’s) that I was already somewhat insulin resistant, even tho my blood glucose numbers never revealed a problem. Insulin resistance must factor in, I would suspect. Whatever the reason, I’m happy to be losing a lb a week eating at “maintenance” levels.

          Oh, and lard is lovely. Lost of good saturated and monounsaturated fats, even has some vitamin D in it. Fries things beautifully too 😉

          Ondrej is so confident in his own brilliance, he believes he can come up with an argument that will convince you your personal experiences with high-fat versus low-fat diets didn’t actually happen. Either that, or you’re lying. Rather than admit perhaps he’s wrong about all calories being equal for all people, he’ll decide your results are illegitimate unless you submit to a lie-detector test … just like all researchers do when publishing their results.

          1. Firebird7478

            There was a guy on the Fat Head Facebook page who insisted that low carb dieting was not conducive to weight lifting even though weight lifters for decades ate high protein low carb diets. I posted my results since switching to low carb dieting…my strength maintained in some areas and went up in others. He insisted I was lying.

            Heh-heh-heh … that’s the convenient way some of these folks deal with results that go against their cherished beliefs.

        2. Dave

          @ Tom, We all know that “scientists are freakin’ liars”!

          Gina Kolata and Jules Hirsh. No bias there (sarcasm). Dr. Eades did a write up on that. Essentially, CICO has become a religious debate, but it is a very convenient obfuscatory argument that has the side effect of protecting the interests of the processed “food” industry.

          True dat. It’s the rationale employed by the Corn Refiners Association: all calories are the same, so enjoy your high-fructose corn syrup, but don’t eat too much overall.

        3. Ondrej

          I said:If you contend that you will not gain weight eating excess calories low carb/high fat, then by definition, you will lose weight eating low carb/high fat at maintenance level calories.

          “That is a completely illogical statement. What the body decides to do with more calories than it needs isn’t the same as what the body decides to do with exactly the number of calories it needs.”

          Really?The study determined subject’s maintenance diet under lab conditions, changed their maintenance diet to HFLC while maintaining the same number of calories and they din’t lose weight.

          [Once again, limiting people to a maintenance level of calories tells us nothing about what happens when they over-consume calories. If you don’t believe the body makes decisions about what to do with excess calories based on whether they come from fats, proteins or carbohydrates, that’s all it is: your belief. You have cited no research whatsoever to back up that belief.

          And of course, you’re still taking the stupid position of trying to tell those of who have stuffed ourselves with LCHF foods without gaining weight that we didn’t experience what we experienced.]

          And you just stated it does not make a difference? Congratulations! You have just rejected the LCHF MAD (Metabolic Advantage Dogma), repeated ad nauseum by Atkins, Eades et al contending LCHF ceteris paribus will burn additional calories by magic. I knew there was hope for you.

          [You might try reading what Dr. Eades wrote before you criticize him. He said specifically that if there’s a metabolic advantage at low calorie levels, it’s quite small. He wrote in the first Protein Power book (which I have) that burning body fat always requires a calorie deficit, but the foods we consume have a profound influence on whether or not we feel hungry when creating that deficit. He also wrote that he had patients who consumed 4,000 calories per day on a near-zero-carb diet and didn’t lose any weight, but also didn’t gain any weight, despite eating more calories than before, so something about the diet caused them to expend or excrete more calories. (Notice he didn’t claim the calories disappeared into thin air.) That’s exactly what I’ve experienced, what many people I’ve talked to experienced, and what Sam Feltham experienced. So once again, if you think you’re going to come up with some brilliant argument that will convince us that we didn’t experience what we in fact experienced, you might want to stop for a moment and ask yourself how you developed such a giant ego. You may as well try to tell me there’s no precipitation in Tennessee right now even though I can look out my window and see that it’s raining.]

          “Feltham kept detailed data and reported his results.”

          Researchers’ studies are readily available for review. Not quite with Sam’s records. He’s avoided disclosure and transparency like a politician.

          [Say what? He posted every day’s diet down to the gram, along with every day’s results. How exactly is that not transparent?

          What this gets down to is that his results dispute a theory you desperately want to believe, so now you’re in the embarrassing position of saying that the only explanation is that he’s lying — along with everyone else who has had the same experience. Good luck with that argument. It’s really persuasive.]

          “What CRTs refute Feltham’s results? Send me links to all the metabolic ward studies …”

          I’m sorry but you have to do your own research. I suggest you start with Anthony Colpo’s The Fat Loss Bible. It contains links to all MWS published in the English language.

          And you don’t even have to buy it. You can borrow it from your good friend Richard Nikoley.

          [I don’t have to buy it. I have a copy and read it a long time ago. There are no metabolic ward studies cited in that book that demonstrate what happens when people consume 5,000+ calories per day of high-carb versus high-fat foods. So once again, you’re embarrassing yourself by saying the scientific evidence proves Feltham couldn’t have achieved the results he claims, when in fact you cannot cite any such scientific evidence. If you can find a study in which researchers put lean, healthy young men on a 5,700 calorie diet of either low-fat or low-carb foods and compared the results, send me the link. If you can’t find such a study, then have enough intellectual honesty to admit that perhaps Feltham did in fact achieve the results he claimed — or at least stop calling him a liar based on your deep familiarity with non-existent studies.]

          I want to close by stating that I hold no animosity towards you, I’m not persecuting you nor am I trying to get you. I’m only trying to help you.

          [Much appreciated, but I don’t see how trying to convince me I didn’t experience what I’ve experienced is supposed to help me.]

          1. Ondrej

            I’m disappointed that you have chosen faith over science. But it’s your choice.

            You remind me of local folks that claim to have met virgins that have relayed to them personal secret messages.

            Perhaps you have taken this position because your livelihood depends on it.

            In few years I’ll be working in my profession, helping people and saving lives.

            On the other hand, you’ll still be hustling DVDs and bamboozling desperate Mastodons into buying your free annual cruise where they’ll be insulted on board by the Swede doctor.

            Peace and love!

            Someone with the attitude required to be a good scientist would look at Feltham’s results and say to himself, “Wow, that’s fascinating. That isn’t what I expected. I need to look into this further and see what I can learn from it.” By contrast, someone with the attitude of “I already know everything there is to know on the subject and therefore any results that don’t meet my expectations must be fraudulent” would be a very lousy scientist. So you’ll pardon me if I respond to you holding yourself up as an example of someone thinking like a scientist by taking a moment to laugh my ass off.

            I noticed you conveniently chose not to address any of my points, including my challenge to find a study proving that Sam Feltham’s reported results aren’t possible. So after first claiming the science proves him wrong, you’re now asking us to simply accept your explanation that he must be lying. I’m disappointed that you’re asking us to choose faith over science, and I already feel sorry for your future patients. When they cut calories and don’t lose weight as predicted by the calories formula — as has happened with people over and over and over — you’ll assume they’re lying and will therefore be the kind of doctor who is part of the problem.

            Meanwhile, I’ll continue receiving emails every week from people thanking me for giving them information that helped them to lose significant weight for the first time in their lives. (I assume, of course, your explanation for all those “Letters From Viewers” posts is that I made them up or that the people writing them were lying. That seems to be your go-to rationalization for results that don’t fit with your beliefs. Hey, whatever it takes to avoid considering the possibility that some of your opinions might be wrong — because real scientists never change their minds. )

            If you ever decide to stop being pig-headed and inexplicably cocksure of your own brilliance and complete mastery of the subject matter, I’d suggest you pick up a copy of “The poor misunderstood calorie.” Then you might stand a snowball’s chance in hell of grasping the science.

        4. Chuck

          Facts, huh? When did “Jillions” become a scientific number. So the twenty some pounds I have lost on a LCHF diet were all water? Surprised I wasn’t making sloshing noises when I walked. I’m surprised I could move at all, or even be alive with my muscle an organ tissue being so water logged.

          According to Wikipedia, a man of average weight (154lbs.) has approximately 10.5 gallons of total body water, averaging 57% of his total weight, but obesity decreases the amount of body water as low as 45%.

          “But when carbohydrate levels are low in a diet and fat content is high, people lose water. That can confuse attempts to measure energy output. The usual measurement is calories per unit of lean body mass — the part of the body that is not made up of fat. When water is lost, lean body mass goes down, and calories per unit of lean body mass go up. It’s just arithmetic.”

          So this statement is saying that low-carbers have more energy, because carbs water the fuel source down? I can’t argue with that arithmetic ;). That explains why I felt so horrible on a high-carb diet.

          This article is full of hocus-pocus, or if you prefer the scientific term– B#!!S*&!

      3. Dave

        I don’t expect Ondrej to actually read this, so it’s more for Tom and the other readers.

        So, um, yea, this single ‘study’ cited by Ondrej is being used to try to refute Sam’s results? Dr Eades summarized Gary Taubes refutation of Gina Kolata very nicely. The comments are very interesting as well. Notice that this is a six year old argument that anyone with a search engine can look up. I find it amazing that Sam is being accused of lying when Gina’s own assertions don’t stand up to scrutiny.

        One key point that Dr Eades made is that subjects for the original experiment were selected for their ability to remain weight stable on the pre-experiment control diet. How are we supposed to decide whether macronutrient ratio is important when the experiment is initially biased towards people who can still maintain weight stability no matter what they eat (as opposed to those of us who have damaged metabolisms)?

        No one here is denying the Laws of Thermodynamics. Energy is energy is energy (Which is what CICO believers call “a calorie is a calorie is a calorie”).

        The point that Sam is making, I believe, is that complex biological systems like humans respond in complex ways to the chemical make up of substances ingested. 500 calories of glucose will have a different impact on a living being than say 500 calories of palmitic acid. One obvious effect will be on body composition (for example, fat gain or loss) which is regulated by hormones. On the other hand, if you truly believe that 500 calories of glucose, fructose, stearic acid, ethanol, etc., all affect body composition equally, then why not ingest 500 calories of kerosene or methanol and see what that does to your body composition…

        PS, I only ever had high school physics and chemistry (back in the ’80s). If a medical student of today can’t grasp the nuances that CICO doesn’t explain, then I weep for the future.

        Gary Taubes has a degree in physics from Harvard and a master’s in aerospace engineering from Stanford. His first books were on physics. It’s just a wee bit unlikely he didn’t stop and consider whether or not his ideas would violate the laws of physics. The difference between him and newspaper reporters who insist the law of thermodynamics prove him wrong is that he has the intelligence and background to grasp why his ideas DON’T violate the laws of thermodynamics. He wrote an entire chapter on that topic in “Why We Get Fat.”

      4. Larkspur Morton

        The NYT article proves nothing — yes, there is water weight lost early on with LCHF diets but after that, fat is lost much more easily. One reason is that most of the energy the body and brain is using on a ketogenic diet are from fats. being keto-adapted makes it very easy for the body to use stored fat in addition to dietary fat for energy.
        also, in the research article, dieters were in controlled envt – hides one of the greatest benefits of the LCHF diet – that one’s hunger decreases dramatically. There is a difference between simply eating less carbs and more fat vs. eating ketogenically that change over one’s metabolism, and makes a bigger difference in weight loss ease.

    2. Mike

      Are you Eveyln at Carbsaner or just copying her stuff. Was reading her blog this evening where she had written

      ” Speaking of headlines, Diet Doc jumped on the publicity stunt bandwagon of Sam “Look Ma Carbs Made Me Grow Taller” Feltham. Most recently Sam gained more weight gorging on a carby junk diet than he did when he shoveled 3000 cal/day extra in nuts. Doc weighs in: Is Overeating Carbs Worse Than Overeating on an LCHF Diet? It’s OK to overeat LCHF because you won’t have to “pay” for your gluttony. Or is the correct interpretation that overeating LCHF is not to be derided because your body wastes the excesses and you won’t gain as much weight. Or is there something just pious about advocating LCHF. Yeah, that’s it.
      A calorie is not a calorie. This has already been proven in study after study, but Feltham provides us with a nice real world illustration.
      Yeah, because all of those metabolic ward studies that demonstrate time and again that a calorie is indeed a calorie are no substitute for free-living studies with questionable accountability, or especially the “real world” example of a skinny dude running fatloss bootcamps where we have only his word that he even did what he claims, and he can’t even be bothered to verify what his weight maintaining caloric intake is to begin with.”

      I am sure that she would appreciate some attribution.

  12. Kristin has a wonderful article on how our bodies use the macro-nutrients we put into them. ( Sam’s experiment corroborates the information presented there.

    Protein is used mostly to rebuild body tissue so it is practically impossible to equate the number of calories ingested in protein with energy output of the body. Fat is used for energy but it is also used for making hormones. Only carbs are primarily used for energy. So it would make sense that the high carb diet would more closely match the CICO model.

    But probably the biggest takeaway for me from this article is that there is no metabolic process in the human body that uses a ‘calorie.’ It breaks down the chemicals and shuffles them off to all kinds of uses. If I were a Bunsen burner this might work out but being a biological being I’m just not. I’m unable to convince my personal trainer of this as he is so very fond of his ‘caloric deficit’ model for health. To his credit after a year he finally realizes that I am maintaining a healthy weight on my 60% fat diet. So he has backed off to just making sure I’m eating enough protein…well, except that he is keenly interested in the results of my bloodwork I’ll be doing soon. 🙂

    Yup, we’re not bomb calorimeters.

    1. Tami

      “Protein is used mostly to rebuild body tissue so it is practically impossible to equate the number of calories ingested in protein with energy output of the body. ”

      Thats really interesting. I had a fairly invasive surgery on Oct 5th, and my nurses and doctor cannot get over how fast I am healing up. I reached the third stage of healing 5 days post surgery – something that should have taken 2-4 weeks. My wounds are almost entirely healed, my brusing is gone and apart from a little tiredness in the evening, I feel great. I must go cook up some more steak 🙂

      Oh and I am female, 40, 5’3, 130 pounds, dont exercise, am moderately active and average 2300 cals a day. Im not gaining.

      1. Galina L.

        It reminds me my experience after a foot surgery – when I came to the office in a week after a surgery to remove stitches it was nothing to do for a nurse – the wound was completely healed, and stitches fell off together with the scab, she even went and brought another nurse to watch such strangely fast healing.

      2. Galina L.

        It reminds me my experience after a foot surgery – when I came to the office in a week after a surgery to remove stitches it was nothing to do for a nurse – the wound was completely healed, and stitches fell off together with the scab, she even went and brought another nurse to watch such strangely fast healing. I also took no antibiotics after that surgery which doctor prescribed just in case.

  13. Anne Robertson

    Ah, Tom, you’ve acquired Diet Doctor’s troll, Ondrej. He claims to be a medical student, but we only have his word for that. Personal experience tells me that high fat, low carb keeps me healthy.

    If he is a medical student, I fear for his patients.

        1. NM

          Ondrej: please, please let me know where you’re going to be doing your medical residency so that I ensure neither I nor my family go anywhere near that establishment in a time of medical need. A doctor who thinks our complex metabolisms can be reduced to nothing more than dumb bomb calorimeters scares the hell out of me!

          1. grinch

            One could say the exact same thing about someone who reduces all of our health woes to ingestion of too many carbohydrates, especially when there are billions of people who have no problem consuming them.

            If I ever claim in one of my posts that all carbohydrates are the same or that nobody can eat a lot of carbohydrates without becoming fat and sick, be sure to jump in and let me know. The difference between our future-doctor troll and me is that if someone tells me he lost 100 pounds on a low-fat diet after failing to lose weight on an Atkins diet, I don’t accuse him of lying about it. I assume he found a diet that worked for him.

      1. Galina L.

        Seriously, what would you do if a patient like me came to your office after her old physician retired , and you noticed serious improvement in all aspects of health(no more seasonal flues, urinary tract infections, no need for an asthma meds, no leg edema, perfect blood pressure at the age 53, perfect waist/ hip ratio) plus lost 30 lb which were not regained. I have it in my medical records that such positive change happened after I started a LC diet several years ago. I visit my GP every 6 month because I need a paperwork for my thyroid panel test. My BMI is still 27, would you tell me to eat a low-fat diet?

    1. Mike

      If you see my post above, Ondrej is copying straight from Carbsane. I have never seen the two in the same room together, coincidence?

      I’ve never seen her in any room. She had to cancel her AHS appearance due to unspecified security concerns.

  14. Pussyfoot

    If you’re looking for more calorie experiments, go on YouTube and search for “Why are thin people not fat?” It was an overfeeding experiment where people gained different amounts of weight even if the calories were the same.

    I saw that. Good stuff. Some barely gained any weight at all.

    1. grinch

      Do these experiments you mention show that this individual variation is influenced by different macro-nutrient compositions?

      Sam consumed the same number of calories in both experiments, but with different macronutrient compositions, correct.

      1. grinch

        I’m talking about the experiment on youtube. The reason I ask is that its already accepted in the mainstream that CI and CO are not independent variables so that is nothing new. But the previous studies on that as far as I know do not show differences due to macro-nutrient composition.

        An experiment similar to Sam’s has never been done unfortunately, and should’ve been NUSI’s first in my opinion.

        I misunderstood the question. The experiment on YouTube (if I’m referring to the same one) was to see what happens when naturally thin people overeat. I don’t believe macronutrients were intended to be part of the equation.

  15. Alex

    What I’d like to see is a repeat of these overeating experiments when Sam has reached his early 40s. At 52, I sure can’t pack away that many LCHF calories and not gain weight. In recent years, I even had to twice count calories for some weeks to drop 7-10 pounds of weight creep and reset my ad libitum eating patterns for slightly less caloric intake.

    It would also be cool if he’d wear some of those activity tracking devices, including one that tracks the pulse, in order to see how his metabolism reacts.

    That’s why I wouldn’t suggest people who’ve battled weight issues attempt his experiment. As a naturally lean guy, his body probably resists packing on extra body fat unless he overwhelms that resistance with refined carbohydrates.

    Chareva is also naturally lean and resists gaining weight, but she did manage to put on 20 extra pounds during her time in the Peace Corps, when she was living on the grains that were the dietary staple in her village. (Those weren’t big meals, by the way.) As soon as she returned stateside and wasn’t living primarily on grains, the weight dropped off.

    I can eat quite a bit of LCHF food without gaining weight, but I wouldn’t want to try 5,700 calories per day for 21 days.

  16. gollum

    The man ate two pounds of carb a day? Wow.

    I suspect none of the fats were ever used.

    Couldn’t that be another way how high carb is hurting your body?
    All the fats immediately go to adipose and you get internal “essential fats starvation”?

    Just a thought. I know it’s a FFA concentration issue.
    Just that the concentration is probably prety low with all the insulin.

    If you over-eat carbs and fats together, then the fat will be stored, yes. Your body will burn the glucose first.

  17. grinch

    Unfortunately for me, in my body weight status is tied to my calorie intake, not macro-nutrient composition. Although I find it easier to eat less when I remove high fat, high sugar industrial foods.

    Everyone’s different. In Chris Gardner’s A-Z study at Stanford, he found that insulin-resistant people lose weight more easily on a low-carb diet. For people who aren’t insulin-resistant, the composition of the diet didn’t make much of a difference.

  18. grinch

    Should we not be concerned with misreporting of Sam’s calorie intake due to his pre-conceived notions about diet? Here is one study of dietary misreporting, but there are many others that back it up with similar findings.

    It is well known at this point that obese people tend to underreport their calorie intake and overreport their physical activity. The question is why would an obese person be more likely to misreport than a lean person? Could it be they want to believe they are doing everything right, so they subconciously skew the numbers in their favor?

    What if in Sam’s case things were reversed. He wants to believe LCHF has a metabolic advantage, so he subconsciously gives himself credit for calories he didn’t actually eat. I would find it hard to eat that many LCHF calories day in and day out and I’m not as lean as him and love to eat.

    There is good reason why free-living studies and metabolic ward studies do not show the same results, and misreporting has a lot to do with it. I think this should be considered before jumping for joy.

    This isn’t a case of Sam guessing at how much he eats on a daily basis, as in the study you linked. (Food recall surveys are notoriously inaccurate, as I’ve mentioned many times.) He measured and logged everything he ate, same as I did when I was on my fast-food diet. It seems highly unlikely that a guy itemizing all his meals down to the gram was under-reporting or over-reporting his intake.

    1. Judy

      “The question is why would an obese person be more likely to misreport than a lean person?”

      Society has a tendency to look down on obese people. You know, the “eat less, move more, and you’ll be fine” crap, which usually doesn’t work. So, maybe they’re misreporting to avoid being looked down on even more. Or, maybe they’re reporting accurately, but others don’t believe them anyway.

    2. Firebird7478

      Sam also mentioned several times in his videos that he had a tough time getting down all those calories. He was eating even when he wasn’t hungry or got past the point of feeling full in order to consume the required amount of calories to conduct the experiment.

  19. Derrick Mitchell

    Tom. Thanks for this article and I am just finishing watching Fat Head. It was entertaining but more factual and the truth is clear. I have been a lower carb person off and on and it’s clear that the processed foods are the problem. Keep up the good work and thanks for the great humour.

    Thanks for watching.

  20. Michael

    this is interesting and it might explain some things observed by those who overeat on a LCHF diet:


    “So yes, dietary fat can be stored as body fat “without” involving insulin. But its worth noting that the stimulation of ASP by chylomicron’s is enhanced in the presence of insulin ( link )”

    “Indeed I do not know of any studies of over-feeding keto in normal lean humans, only to follow them up several years later and find they maintained the elevated fat mass and are resistant to weight loss, both key features of the “obesity ” phenotype.”

    I hope NuSi will do an experiment similar to the one Feltham did but with a daily measurement of hormonal signals insulin, leptin, adiponectin, etc.

  21. Sandra

    He got most (60%+) of his calories from nuts on the low carb diet. Nuts are not highly digested, about 30% goes to waste. So that’s a non-starter.

    1. Tom Naughton Post author

      I’m curious as to why, if you’re citing math as proof his experiment is a “non-starter,” you didn’t finish the math. Take away 30% of the nut calories, he still consumed just short of 4,400 calories per day — 1,300 more per day than his usual diet — but didn’t get any fatter.

      1. Sandra

        Sorry, replied to the wrong thread.

        First, he did gain weight with that experiment.

        Second, how do you know he didn’t gain fat, and lost water weight?
        Many studies conclude that initial weight loss from low carb is from water weight.

        If he had actually measured his body fat % before that study, we would know the answer.
        He ended with 12% body fat. How do we know he didn’t start with 10%?

        Sneaky sneaky!

          1. Sandra

            He never did a bod pod prior to his first experiment, which was the low carb one.

            So we don’t know his baseline body fat % prior to starting the experiment. Sam admits to this as well.

            1. Tom Naughton Post author

              I saw a picture of him on his blog getting a bod pod. Perhaps that was at a different time.

              He did take weight and waist-size measurements. His weight barely budged after the first 21-day experiment (> 5,000 calories of LCHF) and his waist shrunk a bit. So which of these possibilities are you suggesting?

              1. Sam can’t take accurate weight and waist measurements.
              2. Sam is lying about his weight and waist measurements.
              3. He actually got fatter despite almost no weight gain and shrinking a bit around the waist.
              3. He didn’t really and truly consume an extra 1000+ calories per day (and I’m subtracting a third of the nut calories in that).

              Look, Sandra, if you’re wedded to the idea that the source of calories has no effect on metabolism or nutrient partitioning and therefore all calories have the same effect on fat gain, knock yourself out. Stick with that belief and enjoy.

            2. Sandra

              The recent NuSI study actually confirms what I’m saying as well. Low-carb / Ketogenic diets have no metabolic advantage over any other macro-nutrient ratios.

              It’s not so much a “belief”, just fact. That’s probably why Peter Attia left NuSI before the study came out. Truth is a hard pill to swallow.

              But hey, if the low-carb lifestyle works for you — great. Keep at it. Just don’t confuse the facts and be stuck unnecessarily in dogma and confusing other people in the process.

            3. Tom Naughton Post author

              Actually, it did show a metabolic advantage. Energy expenditure increased by 100 calories per day. Read the abstract.

    1. Tom Naughton Post author

      Cool. But of course, the calorie freaks will put themselves through all kinds of mental gymnastics to dismiss the study and cling to their precious (because simple answers appeal to simple minds) CICO theory.

  22. Sally

    Sam Feltham ate 3,000 calories from nuts in his low carb experiment. Nuts are approx. 35% undigestible in the human body.

    Already a fail.

    1. Tom Naughton Post author

      1. Why are you posting under two names?

      2. As I already pointed out, even if we assume a third of the nuts passed through and exclude those calories, he was still more than 1,000 calories per day over his usual diet. According to the calorie freaks, he should have gotten fatter, but he didn’t.

  23. Julianne

    I’m not sure if anyone else mentioned this – but a huge confounder here is the protein content of each diet is vastly different – you simply cannot say the results are related to high or low carb unless you keep the protein exactly the same in both diets. If you were to run stats on this – using a similar experiment with a group – you would probably find this has a major influence. Protein is highly thermogenic, and contributes to lean mass.
    When Sam was talking about this experiment I asked it he would keep protein the same and vary only the fat:carb ratio. He didn’t do this – therefore you can make NO conclusions with respect to the carbs. All you can say here is a lower protein and fat and higher carb diet led to more weight gain than a high protein lower carb diet.
    All low carb diets increase protein dramatically – yet no-one mentions this.
    I’ve done the personal experiment of keeping protein exactly the same and swapping out fat for more paleo carbs – better satiety, better poops, better cholesterol profile and less tummy fat.

    1. Tom Naughton Post author

      He did include an analysis of the predicted lost-calorie effects of both protein and fiber in his upcoming book. Bottom line is that when you include those calculations, there was still a substantial difference in weight gain that can’t be explained by calories alone.

      1. Julianne

        The fact is, adjusting for this is still theory – the only true test is real life. I personally am disappointed he didn’t do the test without the protein confounder. It would have been far more accurate.

        1. Tom Naughton Post author

          Well, I guess that would have made it easier to analyze. But in real life — which I agree is the test that matters — most of us do end up eating more protein if we dump a high-carb diet and adopt an Atkins diet. (Those restricting protein intentionally to please the keto-meter would be the exception.) In my own real-life experiences, I can stuff myself with steaks, eggs, bacon, chicken, sausage, etc., and not gain an ounce if I keep the carbs very low. I’ve done every time I’ve gone on a cruise, sometimes eating four meals per day. Is it the carb restriction? Is the thermic effect of the protein? Who cares? If I can eat like a king without gaining weight, the exact reason ultimately isn’t that important.


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