Comment by mkn | Hacker News Reader

Comment by mkn | Hacker News Reader

Since a pound of fat is roughly equal to 3500 calories, this means you accumulate roughly 7000 calories worth of fat every year. Divide that 7000 by 365 and you get the number of calories of fat you stored each day and never burned roughly 19 calories. Let’s round up to 20 calories, so we have a nice round number. (In the new book I discuss this issue in a chapter called "The Significance of Twenty Calories a Day.")

He neglects the metabolism one needs to maintain that fat tissue each and every day. One rough rule of thumb is 11/cal/day/pound to maintain your weight. Being 40 lbs overweight thus takes not just his (apparently trivial) 20 calories per day to gain that weight, but 440 additional calories per day to maintain it. If the weight was truly gained in a linear fashion, that's an average of 220 calories per day to maintain it, above the 20 per day to gain it. This is the real math. This is why weight gain and weight loss correspond to gross caloric intake and expenditure. The dynamic equilibrium of an organism's weight is a feedback mechanism in which the mass of the organism appears as the magnitude of the gain on the negative feedback term.

Someone who is truly obese, say someone who is 300 lbs who should 180 lbs, for example, is running an ongoing daily calorie surplus of 1320 calories through diet and lifestyle, not the 60 per day that Taubes would suggest. This is not an insignificant disparity, and this guy's work will be truly harmful wherever it is--help us all--taken seriously.

I could maybe take the rest of his ideas more seriously if he were not so obviously wrong right out of the gate.

I'm not sure how the maintenance expenditure is relevant to his point - the point is that if you only eat 20 calories/day more than you "should" (the amount that would cause your weight to remain the same) then you will gain the weight. The fact that the baseline changes is an irrelevant detail. Regardless of what the baseline is at any given point, how does the system (meaning the person's body+brain) know when to stop eating?

the point is that if you only eat 20 calories/day more than you "should" (the amount that would cause your weight to remain the same) then you will gain the weight.

The point is that you won't ever gain the 40 lbs if you only eat the 20 cal/day extra.

Imagine you start eating the 20 cal/day extra. Initially, your weight climbs at 1 lb/year. However, by the time you gain that one pound, you have to spend an additional 11 cal/day to maintain that weight, so now you're gaining at a bit less than 1/2 lb/year. By the time you (asymptotically) approach having gained 20/11 ~ 1.9 pounds (which really only happens at infinity, but let's imagine you splurged to put yourself over), then you're at maintenance for your new weight. In order to gain more, you have to increase your uptake again.

As you gain weight, you accumulate metabolic load, so it takes a serious surplus of calories to continue to gain in the long term.

The steady-state condition of obesity requires a large ongoing surplus of calories to maintain.

Plausible fixes are incorporating more fiber in the diet to increase the feeling of satiety, reduce portions generally, cut out high-calorie drinks, and start exercising, even if only moderately but consistently.

Succinctly, the amount you "should" eat is not the amount to maintain your current weight, but the amount you need to maintain a healthy weight.

This is all true, but I'm wondering if you are mistaking a strawman for Taubes actual argument. The bit about '20 calories/day' is his attempt to explain the current philosophy, which he feels is fatally flawed, in the way you mention among others. He's setting up this argument merely to tear it down. Despite being the simplified version of the standard wisdom, he agrees with you that it's wrong.

His actual point is at the end: 'Maybe when we get fat it’s because those physiological, metabolic and genetic factors you mentioned are dysregulating our fat tissue, driving it to accumulate too much fat'. He might be wrong about this, but his point is that the difference between an obese and non-obese person cannot be fully explained by an intake difference of 20 calories per day over a lifetime. There must be something else in play.

...his point is that the difference between an obese and non-obese person cannot be fully explained by an intake difference of 20 calories per day over a lifetime...

If that's his point, it's wrong. The intake difference between the obese person and the non-obese person is just shy of 1 big mac/day after 40 years (440 cals maintenance + 20 cals excess).

Defen is correct, you're using a different referent of "excess". Taubes means excess of maintenance (which may vary), not excess from ideal. No one is disputing that if a 300 lb person ate what a 180 lb person needs, he would probably loose weight. Taubes refers to this low-cal diet as a starvation diet, but his book has more to say about its problems and limitations. His point is that staying within 20 cals of maintenance by counting is nearly impossible, so counting isn't what is responsible for weight control, otherwise everyone would be wildly far from ideal weight.

I don't know the answer, but I presume that 40 lbs of fat requires far fewer calories to maintain than 40 lbs of lean body mass. Does the 11/cal/day/pound rule of thumb apply to fat? Muscle?

I have no actual numbers on hand but muscle is a lot denser and needs a lot more energy to maintain; putting on even a small amount of muscle and doing just enough exercise to keep the muscles around helps with weight loss (as well as general fitness)

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