Fat Mice And The Laws of Thermodynamics

      73 Comments on Fat Mice And The Laws of Thermodynamics

In a Weight Watchers discussion group, someone recently posted this advice:

The key to successful weight loss is simple mathematics . . . ingest fewer calories than calories expended in a day.

That second part of that sentence is, of course, correct. Your body won’t tap the energy reserves in your fat cells unless the energy is needed.  You have to expend more than you ingest.  But that doesn’t mean successful weight loss is all about “simple mathematics.”  Biological systems aren’t simple.

Unfortunately, too many people grasp (again, correctly) that gaining or losing weight requires an imbalance between the energy consumed and the energy expended, but then take a leap in logic and conclude that:

  1. Consuming additional calories is the root cause of becoming fatter (as opposed to a response to storing more calories as fat).
  2. Everyone who becomes fatter is either eating more or moving less than before.
  3. Consuming fewer calories will automatically lead to a lower weight and less body fat.

In other words, they think it’s about simple mathematics, just like a savings account.  To dispute any of these conclusions, we’re told, would be to ignore the laws of thermodynamics. So let’s see how that contention holds up in the face of controlled research.

In a study published earlier this year, researchers conducted two experiments, each lasting three or four weeks, in which obese mice were divided into two groups: a control group that ate freely (ad libitum) and a calorie-restricted group. In the first experiment, researchers first recorded the average caloric intake of the mice when they were allowed to eat freely, then limited the calorie-restricted group to 95% of that intake. In the second experiment, researchers observed the on-going caloric intake of the mice allowed to eat freely, then limited the calorie-restricted group to 95% of that intake. In other words, if the mice eating freely ate more, the calorie-restricted mice were given more food … but they were still eating 5% fewer calories than their freewheelin’ cousins.

A legitimate criticism of many diet studies is that the researchers relied on food-recall surveys or diet journals to determine how much people ate. Those methods can be notoriously inaccurate. Realizing this, the researchers on this study elected not to allow the mice to keep their own diet journals. Instead, the researchers precisely measured and recorded how much each mouse ate — even going so far as to examine the little critters’ cages and subtracting any bits of food they found from the food-intake totals.

In both experiments, researchers took precise before-and-after measurements of weight, lean body mass, and adipose-tissue mass. In the second experiment, they also used infrared sensors to track locomotor activity levels (“moving around” to us laypeople), and measured oxygen consumption and carbon-dioxide output to calculate how much energy the mice expended. I’d say that’s about as precise as a diet study gets.

Now, according to Jillian Michaels and the other leading experts in thermodynamics, there are only a couple of possible outcomes for these experiments:

  1. The calorie-restricted mice, who were prevented from making little pig-mice of themselves, ended up weighing less and were leaner.
  2. If the calorie-restricted mice somehow ended up fatter, it could only be because they were far less active than the mice who ate freely.

Yup … if you get fat, by gosh, it means you’re either eating more or moving less. Now let’s look at the actual results:

At the end of first experiment (four weeks), the calorie-restricted mice weighed a teeny bit less than their free-eating counterparts — the difference was not statistically significant, but it was there. However, the calorie-restricted mice also had 68.5% more fat mass, and 12.3% less lean mass.

Being put on a diet made them fatter.

At the end of the second experiment (three weeks), the average weight for both groups was virtually identical — it was also virtually identical to their baseline weights. But the calorie-restricted mice had 43.6% more fat mass and 6.4% less lean mass than the free-eating control mice. Once again, being put on a diet made them fatter.

Well, clearly, those fat little calorie-restricted mice must’ve spent too much time sitting around watching reruns of The Biggest Loser while their free-eating cousins were whipping themselves into shape by running on the big wheel, right?

Nope. According to the study data, there was no difference in locomotor activity levels between the two groups.

The calorie-restricted mice ate less, they moved around just as much, but they ended up weighing the same as the mice allowed to eat freely, and also ended up with more fat and less muscle. Oh, dear me … did these mice find a way to violate the laws of thermodynamics?

No, heck no, for the thousandth time, NO.

The researchers didn’t take body-heat measurements (too bad), but reported that the calorie-restricted mice expended significantly less energy: 5% less overall, and 20% less while at rest. Simply put, their metabolisms slowed down, even though they were just as physically active.  No laws of thermodynamics were violated in the process.

I once sent a link to this study to someone who insisted that according to the laws of thermodynamics, weight gain is caused by eating more or moving less, period.  His reply was something like, “That doesn’t prove anything!  I’m not a mouse.  I’m talking about people.”

Well, I agree that mice aren’t little furry people, which is why I’m not concerned when this-or-that food is shown to trigger cancer in mice.  (Mouse chow probably wouldn’t agree with me either.)  But remember, we’re talking about The Laws of Thermodynamics here.  They don’t apply to one species, but not another.  If mice can become fatter without eating more or moving less, yet somehow avoid violating the laws of thermodynamics in the process, then so can people.

The researchers were at a bit of a loss to explain why the calorie-restricted mice grew fatter, but I’m pretty sure we can rule out gluttony and sloth. They suggested perhaps the mice were reacting to the stress of a limited food intake.

“Reacting,” of course, means something hormonal was going on. (It wasn’t thyroid hormone. The researchers checked.) Perhaps the calorie-restricted mice produced more cortisol. Perhaps evolution geared the mice to respond to the threat of starvation by accumulating more fat, even if it means sacrificing lean tissue.

The point is, they didn’t get fatter by eating too much, and they didn’t get fatter because they decided to expend less energy. They began to expend less energy (in spite of being just as active) because they were being hormonally driven to accumulate more fat, even on less food.

Doesn’t that sound something like the process described by a best-selling science journalist who supposedly doesn’t understand that his hypothesis would violate the laws of thermodynamics?

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73 thoughts on “Fat Mice And The Laws of Thermodynamics

  1. Lawrence

    So, what you’re saying is that calorie intakes aren’t the major issue when it comes to nutrition, but that the quality of the food you are ingesting is which in turns affect one’s metabolism? If so, that is intriguing.

    If your metabolism is working correctly (which the proper diet helps to maintain), your appetite will take care of itself. Over-eating is a symptom, not the cause.

    Reply
  2. Poisonguy

    Let’s take another quick look at the “insignificant” weight change claim. To say the mice from both groups had insignificant weight change, comparatively, I think, is misleading as this weight change is measure in grams. But their intake was measured in calories, not grams, so let’s stick with calories, if you will. So, calorie-wise, the calorie-restricted mice have had an enormous shift in energy; an increase in energy (calories) by replacing bodily protein (4 kcal/g) with fat (9 kcal/g)—with far fewer calories ingested. So, they may not have gained weight, but they experienced an enormous increase in potential energy which is quite significant (let’s do an experiment to see who can burn it off quicker!). This is a great study to show the foolishness of the calories-in/calories-out riffraff.

    And according to the “it’s all about the calories” crowd, they should’ve lost weight compared to the control mice. Ending up at the same weight with a higher percentage of body fat is significant.

    Reply
  3. Charise

    My understanding of IF is this:
    If you are ‘starving’ yourself but eating meat and things that don’t spike your insulin (i.e. the things we were MADE to eat), then your body is able to access your fat stores = you keep your muscle, and lose your fat first.

    If you are starving yourself but eating nothing but whole grains and all that Weight Watchers garbage, then your body has no way of burning anything but muscle for fuel since you’re in a constant state of elevated insulin.

    So instead of your body naturally realizing “okay, food is scarce, we’ll use some of that butt fat to last through this” your body goes “WE HAVE NO FAT ANYWHERE, I CAN’T FIND IT, MAYDAY, MAYDAY, LIQUEFY THE BICEP! EAT MORE! STOP MOVING! AUGGHHH!”

    I believe that’s why I felt absolutely starved when I tried Slim Fast.

    Reply
  4. Poisonguy

    Let’s take another quick look at the “insignificant” weight change claim. To say the mice from both groups had insignificant weight change, comparatively, I think, is misleading as this weight change is measure in grams. But their intake was measured in calories, not grams, so let’s stick with calories, if you will. So, calorie-wise, the calorie-restricted mice have had an enormous shift in energy; an increase in energy (calories) by replacing bodily protein (4 kcal/g) with fat (9 kcal/g)—with far fewer calories ingested. So, they may not have gained weight, but they experienced an enormous increase in potential energy which is quite significant (let’s do an experiment to see who can burn it off quicker!). This is a great study to show the foolishness of the calories-in/calories-out riffraff.

    And according to the “it’s all about the calories” crowd, they should’ve lost weight compared to the control mice. Ending up at the same weight with a higher percentage of body fat is significant.

    Reply
  5. Charise

    My understanding of IF is this:
    If you are ‘starving’ yourself but eating meat and things that don’t spike your insulin (i.e. the things we were MADE to eat), then your body is able to access your fat stores = you keep your muscle, and lose your fat first.

    If you are starving yourself but eating nothing but whole grains and all that Weight Watchers garbage, then your body has no way of burning anything but muscle for fuel since you’re in a constant state of elevated insulin.

    So instead of your body naturally realizing “okay, food is scarce, we’ll use some of that butt fat to last through this” your body goes “WE HAVE NO FAT ANYWHERE, I CAN’T FIND IT, MAYDAY, MAYDAY, LIQUEFY THE BICEP! EAT MORE! STOP MOVING! AUGGHHH!”

    I believe that’s why I felt absolutely starved when I tried Slim Fast.

    Reply
  6. Quinlan

    Nonsense! Those fat mice need to get their lazy arses off the couch and stop stuffing their greedy faces with big macs and twinkies! 😉

    If they’re like humans, the leaner miced looked at them and said, “How can you let yourself go like that?”

    Reply
  7. Quinlan

    Nonsense! Those fat mice need to get their lazy arses off the couch and stop stuffing their greedy faces with big macs and twinkies! 😉

    If they’re like humans, the leaner miced looked at them and said, “How can you let yourself go like that?”

    Reply
  8. Jerica Michael

    LOL I just have to say, there are many times in which I would love the chance to do like on facebook and ‘like’ people’s comments. XD Many of them are just as funny as the post. I’m mainly looking at Charise’s here.

    Reply
  9. Jerica Michael

    LOL I just have to say, there are many times in which I would love the chance to do like on facebook and ‘like’ people’s comments. XD Many of them are just as funny as the post. I’m mainly looking at Charise’s here.

    Reply
  10. Ben

    Hi Tom love the movie and the site. I found Gary Taubes new blog the other day and on there a very adamant and lets just say acidic person post a bunch of stuff about how Taubes knows so little about biochemistry. He then linked a site called http://carbsanity.blogspot.com and the first article referenced this article you wrote. I didn’t really have time to read the whole article but he basically said you were misleading in your post. One thing that did catch my eye was a comment that basically sad while rats didn’t get fatter they got fattier, by which I think he meant they didn’t gain weight but their body mass shifted to have a higher percentage of fat. And then uses that to explain why the insulin stores fat theory is wrong. Now I admit I didn’t read much of the site since I was in a hurry and his comments make him sound like a “don’t listen to those low carbers I’m the only one to listen too” kind of guy but I was wondering if you know what the hell he is talking about on his site…is he full of bologna?

    The site he linked is run by a mentally unbalanced person who has become obsessed with Gary Taubes and is now stalking him all over the internet and leaving dozens of comments on any site (blog, news site, etc.) that references him, all while insisting on remaining anonymous herself and apparently not recognizing that the stalking behavior is borderline insane — especially since 1) people who read Taubes and accept his hypothesis will end up going on the same diet she follows herself, and 2) she already has a blog in which to express her opinions, which ought to be enough for a mentally healthy person. Imagine what it would say about my emotional health if instead of being satisfied with writing my opinions on my blog, I also spent all day leaving dozens of comments on any site I could find that recommended a vegetarian diet, telling them how wrong they all are.

    Gary Taubes tried to engage her in an actual discussion, but she preferred to continue stalking and attacking him, so he gave up. She’s now attempting to pick fights with me as well, which I’ve elected to ignore. I’ve dealt with enough not-quite-sane people to know that the best strategy is to refuse to engage. They will happily spend eight hours arguing that the sun is blue, and when you finally give up and walk away because you actually have other things to do, they’ll say, “Aha! Afraid to debate me, aren’t you, huh? Huh?” Then they’ll call you at home to continue the argument. That’s pretty much what our almost-sane stalker is like, which makes the “sanity” part of the blog name worth a chuckle, if nothing else.

    Reply
  11. Ben

    Hi Tom love the movie and the site. I found Gary Taubes new blog the other day and on there a very adamant and lets just say acidic person post a bunch of stuff about how Taubes knows so little about biochemistry. He then linked a site called http://carbsanity.blogspot.com and the first article referenced this article you wrote. I didn’t really have time to read the whole article but he basically said you were misleading in your post. One thing that did catch my eye was a comment that basically sad while rats didn’t get fatter they got fattier, by which I think he meant they didn’t gain weight but their body mass shifted to have a higher percentage of fat. And then uses that to explain why the insulin stores fat theory is wrong. Now I admit I didn’t read much of the site since I was in a hurry and his comments make him sound like a “don’t listen to those low carbers I’m the only one to listen too” kind of guy but I was wondering if you know what the hell he is talking about on his site…is he full of bologna?

    The site he linked is run by a mentally unbalanced person who has become obsessed with Gary Taubes and is now stalking him all over the internet and leaving dozens of comments on any site (blog, news site, etc.) that references him, all while insisting on remaining anonymous herself and apparently not recognizing that the stalking behavior is borderline insane — especially since 1) people who read Taubes and accept his hypothesis will end up going on the same diet she follows herself, and 2) she already has a blog in which to express her opinions, which ought to be enough for a mentally healthy person. Imagine what it would say about my emotional health if instead of being satisfied with writing my opinions on my blog, I also spent all day leaving dozens of comments on any site I could find that recommended a vegetarian diet, telling them how wrong they all are.

    Gary Taubes tried to engage her in an actual discussion, but she preferred to continue stalking and attacking him, so he gave up. She’s now attempting to pick fights with me as well, which I’ve elected to ignore. I’ve dealt with enough not-quite-sane people to know that the best strategy is to refuse to engage. They will happily spend eight hours arguing that the sun is blue, and when you finally give up and walk away because you actually have other things to do, they’ll say, “Aha! Afraid to debate me, aren’t you, huh? Huh?” Then they’ll call you at home to continue the argument. That’s pretty much what our almost-sane stalker is like, which makes the “sanity” part of the blog name worth a chuckle, if nothing else.

    Reply
  12. Carol Bardelli

    “Clearly those babies are just nursing too darned much and not spending enough time playing with their toes. Someone should have a talk with them.” LOL!

    Mehmet Oz back pedaled on the whole grains on Good Morning America. He admitted they could be toxic. Maybe he’ll promote low carb openly one day. Jillian, on the other hand, is a lost cause. Biggest Loser is in bed with grain purveyor companies like Subway and cereal makers.

    I’m pleased to hear Dr. Oz is willing to change his mind.

    Reply
  13. Carol Bardelli

    “Clearly those babies are just nursing too darned much and not spending enough time playing with their toes. Someone should have a talk with them.” LOL!

    Mehmet Oz back pedaled on the whole grains on Good Morning America. He admitted they could be toxic. Maybe he’ll promote low carb openly one day. Jillian, on the other hand, is a lost cause. Biggest Loser is in bed with grain purveyor companies like Subway and cereal makers.

    I’m pleased to hear Dr. Oz is willing to change his mind.

    Reply
  14. Ben

    Hey Tom thanks for getting back to me. I’m new to this side of the health stuff, I like most people believed the government recommendations. My eyes were definitely opened with your movie, Gary’s books and Mark Sisson’s website. Like every community it does attract its kooks and I don’t know who and where they are yet. I found the time to actually read some of the posts on that site…and lets just say I won’t go back. Even if I found the science listed on there convincing (I’m a high energy physicist so I do actually know something about science) I wouldn’t go back. There is a way to get ideas out there without being that acidic, its just unpleasant to read.

    My attitude exactly. The shame of it is, there’s some good stuff there. But there are also some very strange leaps in logic.

    Reply
  15. Ben

    Hey Tom thanks for getting back to me. I’m new to this side of the health stuff, I like most people believed the government recommendations. My eyes were definitely opened with your movie, Gary’s books and Mark Sisson’s website. Like every community it does attract its kooks and I don’t know who and where they are yet. I found the time to actually read some of the posts on that site…and lets just say I won’t go back. Even if I found the science listed on there convincing (I’m a high energy physicist so I do actually know something about science) I wouldn’t go back. There is a way to get ideas out there without being that acidic, its just unpleasant to read.

    My attitude exactly. The shame of it is, there’s some good stuff there. But there are also some very strange leaps in logic.

    Reply
  16. Dana

    Miss (In)Sanity has issues with simple math, I’ve found. Some commenter on one of Jimmy Moore’s blogs stated that if you’re metabolically messed up you could wind up gaining two pounds of fat instead of one from eating a pound of junk food because your body would freak out and convert a pound of muscle into a pound of fat. This lady went nuts on him and ranted that it was impossible to gain more than one pound of weight from one pound of food. But he wasn’t talking about one pound of *weight*, he was talking about one pound of *fat.* It certainly *is* possible to change your body composition that way. Like the Twinkie Diet guy, who did indeed get his overall weight down to a somewhat normal BMI–but when he posted his body comp test results on his Facebook, he’d lost several pounds of lean mass and his bodyfat percentage was just under obese level for his demographic category.

    You’ll notice that a lot of these people arguing for calories and against hormonal factors in weight gain always want to bring the argument around to focus on WEIGHT loss, not FAT loss. If they put their focus on fat loss where it should be, after all, their approaches to the problem would soon be discredited and they’d all be out of a job. Nobody dealing with a weight problem wants to sacrifice muscle and internal organs to solve said weight problem–not really, and if given a viable alternative to that, will abandon those muscle-consuming weight-loss programs in droves.

    Kind of makes me wonder if CarbSane’s really Jillian Michaels, since Gary’s joked a few times about her in interviews lately…

    I don’t read her posts, but apparently when I wrote about the mice who got fatter on 5% fewer calories than the control group, she tried to explain how they became “fattier” but not “fatter.” So I guess if I’m 6’0″ and weigh 200 with 30% body fat, I’m no “fatter” than a guy who’s 6’0″ and weighs 200 with 5% body fat. I’m just “fattier.” Now that’s … uh … a beautiful mind at work.

    Reply
  17. Dana

    Miss (In)Sanity has issues with simple math, I’ve found. Some commenter on one of Jimmy Moore’s blogs stated that if you’re metabolically messed up you could wind up gaining two pounds of fat instead of one from eating a pound of junk food because your body would freak out and convert a pound of muscle into a pound of fat. This lady went nuts on him and ranted that it was impossible to gain more than one pound of weight from one pound of food. But he wasn’t talking about one pound of *weight*, he was talking about one pound of *fat.* It certainly *is* possible to change your body composition that way. Like the Twinkie Diet guy, who did indeed get his overall weight down to a somewhat normal BMI–but when he posted his body comp test results on his Facebook, he’d lost several pounds of lean mass and his bodyfat percentage was just under obese level for his demographic category.

    You’ll notice that a lot of these people arguing for calories and against hormonal factors in weight gain always want to bring the argument around to focus on WEIGHT loss, not FAT loss. If they put their focus on fat loss where it should be, after all, their approaches to the problem would soon be discredited and they’d all be out of a job. Nobody dealing with a weight problem wants to sacrifice muscle and internal organs to solve said weight problem–not really, and if given a viable alternative to that, will abandon those muscle-consuming weight-loss programs in droves.

    Kind of makes me wonder if CarbSane’s really Jillian Michaels, since Gary’s joked a few times about her in interviews lately…

    I don’t read her posts, but apparently when I wrote about the mice who got fatter on 5% fewer calories than the control group, she tried to explain how they became “fattier” but not “fatter.” So I guess if I’m 6’0″ and weigh 200 with 30% body fat, I’m no “fatter” than a guy who’s 6’0″ and weighs 200 with 5% body fat. I’m just “fattier.” Now that’s … uh … a beautiful mind at work.

    Reply
  18. Steve

    “What would happen? I’d say the 2nd group would lose more fat. Why? Because of, in part, the TEF of protein. Then get the calories-in/calories-out people to explain the result.”

    The thermic effect of food in no way violates the energy balance equation.

    “Like the Twinkie Diet guy, who did indeed get his overall weight down to a somewhat normal BMI–but when he posted his body comp test results on his Facebook, he’d lost several pounds of lean mass and his bodyfat percentage was just under obese level for his demographic category.”

    This is incorrect; as you can see on his facebook page, his bodyfat percentage went down.

    http://www.facebook.com/pages/Prof-Haubs-Diet-Experiments/152304481454281?sk=photos

    Can’t quite figure out who you’re responding to, since this goes back a ways. From what I saw of his records online, he did indeed lose both body fat and lean tissue.

    Reply
  19. Steve

    “What would happen? I’d say the 2nd group would lose more fat. Why? Because of, in part, the TEF of protein. Then get the calories-in/calories-out people to explain the result.”

    The thermic effect of food in no way violates the energy balance equation.

    “Like the Twinkie Diet guy, who did indeed get his overall weight down to a somewhat normal BMI–but when he posted his body comp test results on his Facebook, he’d lost several pounds of lean mass and his bodyfat percentage was just under obese level for his demographic category.”

    This is incorrect; as you can see on his facebook page, his bodyfat percentage went down.

    http://www.facebook.com/pages/Prof-Haubs-Diet-Experiments/152304481454281?sk=photos

    Can’t quite figure out who you’re responding to, since this goes back a ways. From what I saw of his records online, he did indeed lose both body fat and lean tissue.

    Reply
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