A few weeks ago I was interviewed by Sam Feltham on his Smash The Fat Live show. He told me at the time that he was running an N=1 experiment to see what would happen if he consumed 5,000 calories per day on a high-fat/low-carb diet for 21 days.
Before we look at the final results, here are some quotes from an article Sam wrote when he was halfway into his experiment:
10 days ago I started a 21 day experiment where I eat 5,794 calories of a low carbohydrate high fat diet to see if a calorie is really just a calorie. I have come across some militant scientists, who say my experiment is bogus, and some very supportive ones, who have applauded me for trying to push science forward. The only premises that I’m starting with are that a calorie is a calorie, that if you eat more than you burn you put on weight and that 1lb (0.45kg) of fat is 3,500 calories.
At the start of my 21 day experiment I weighed in at 85.2kg in the morning and 86kg in the evening making my mean for day 1, 85.6kg. My waist measurement was 78cm in the morning and 81cm in the evening making my starting mean 79.5cm. As it stands from this morning, halfway, I’m in a calorie surplus of 26,841 and according to the calorie formula I should be 3.5kg heavier than when I started at 89.1kg. On day 10 of the experiment I currently weigh 85.7kg and my waist is 76cm, so a gain of 0.1kg and a loss of 2.5cm.
So after 10 days, he gained a miniscule amount of weight, but lost a bit of fat around the middle. In other words, he probably gained a bit of lean tissue.
Now here’s his report after 20 days of consuming more than 5,000 calories per day:
Day 20, and I am 86.7kg at 3am as I’m off for the weekend! Which is 0.4kg down from last night’s weigh in where I was 87.1kg making my mean for yesterday 86.45kg, which is 0.85kg up from my starting mean weight! According to the calorie formula I should be up by 6.6kg as I’m now in a 51,239 calorie surplus to 92.2kg from my starting mean weight of 85.6kg.
My waist measurement this morning was 76cm which is 2cm down from my starting AM measurement. Last night I was 77.5cm giving me a mean waist of 76.5cm, which is 3cm down from the start!
Translation for those of us not on the metric system: he gained slightly less than two pounds, but lost just over an inch around the waist. According to the usual (and wrong) interpretation of the calories-in/calories-out theory, he should have gained more like 15 pounds.
Predictably, the calorie fanatics who commented on his experiment are insisting that he simply has a super-high metabolism. Oh, really? By that logic, he should have been wasting away when he was on his normal diet of somewhere between 2,000 and 3,000 calories per day. And yet he wasn’t. So that “super-high metabolism” is a new development.
In two of my posts about the low-carb cruises I attended, I mentioned that despite eating three and sometimes four meals per day – larger meals than I typically eat at home, by the way – I didn’t gain any weight. In fact, on the first low-carb cruise I attended, I weighed myself in the ship’s health club on the first and last days of the cruise. I was a pound lighter on the last day.
People who insist weight loss and weight gain is all about counting calories like to point to studies of semi-starvation diets – people consuming 1,000 calories per day or thereabouts. Yup, in most of those studies, there’s not much of a difference between low-carb and low-fat diets. (In others, there was a difference. The low-carbers lost more.)
But in my experience, the advantage of a low-carb diet isn’t in losing more weight at a very low calorie intake. It’s in not gaining weight at a high calorie intake. Pardon me for comparing apples to oranges a bit here, but when Morgan Spurlock consumed 5,000 calories per day of high-sugar, high-carb food in Super Size Me, he gained 24 pounds in 30 days and got fat around the belly. Sam Feltham gained slightly less than two pounds while losing in inch around his waist.
After my first low-carb cruise, I wrote to Dr. Mike Eades to ask why I hadn’t gained weight while stuffing myself with eggs, bacon, sausage, burgers, steaks, lobster, salads with creamy dressing, etc. He replied that he’d seen the same phenomenon dozens of times with his patients. Some of them took being on a low-carb diet as an excuse to stuff themselves, then were disappointed when they didn’t lose weight, or only lost a couple of pounds in a month. (For the record, Dr. Eades has always insisted that losing weight requires a calorie deficit. Read the original Protein Power book if you think otherwise.) When he checked the disappointed patients’ detailed food journals, he found that they were consuming 4,000 calories per day or more. And yet they didn’t gain weight, or even lost a bit.
Why? I don’t know exactly. Neither does Dr. Eades. He told me all we know is that the body finds ways to burn the extra calories. The body may produce extra heat, it may repair and replace cells at a faster rate, it may engage in other energy-using processes no one has identified yet, or some combination of all three. Somehow, given the right hormonal conditions, a body can resist accumulating fat even with a higher-than-usual intake of calories. Dr. Richard Feinman told me pretty much the same thing.
And by the way, neither of them claimed that the extra calories vanished into thin air. They claimed that somehow, a dramatic increase in calories in caused a compensating increase in calories out. That’s what happened to me when I pigged out on the cruises, and it’s what happened to Sam Feltham during his 21-day experiment.
And no laws of thermodynamics were harmed in the process.