Autoimmune Thyroid Disease

An Unfortunate and Lengthy Adventure in Misdiagnosis

More boring weight loss stuff

with 2 comments

I’m being controversial again. I seem to find myself nit-picking over details. I’m told it’s bad form to quote oneself. With that in mind, here’s what I just posted on LCHF:

I feel somewhat misinterpreted again: I didn’t say calories don’t count, I said they aren’t the one and only factor.

The basal metabolic rate of normal, healthy adults with normal thyroid hormone levels still varies between +/- 15% of the mathematic calculation. A calculator might calculate you to have a BMR of 1,800 kcals, but different individuals of the same weight, size, age and activity level may burn anywhere between 1,530 – 2070 kcals per day in reality.

This is even before we consider individuals with an underactive thyroid, who may burn as much as 25% less energy than predicted. The same study you describe that shows the clear underreporting in energy intake in obese patients (presumably “The Calorie: Myth, Measurement and Reality“) admits this metabolic fact but sweeps it under the rug. Furthermore, the study only deals with subjects who are maintaining their weight, not with what happens when calories are genuinely reduced. Nor does it consider that obese patients may be reporting lower calorie intakes to scientists and doctors because they feel ashamed, it doesn’t necessarily mean they are underreporting those additional calories to themselves.

I should be eating around 1,800 kcals a day to maintain my weight, yet I maintain my weight on 2,000 kcals a day, and I maintain my weight on 1,500 kcals a day. I don’t lose weight until I go as low as 1,200-1,300 kcals a day. I use scales religiously when I want to lose weight. This suggests to me at least that my metabolism varies on demand to keep me in a status quo.

Starvation and serious or abrupt calorie restriction can dramatically reduce BMR by up to 30%. Low calorie diets can cause a drop by as much as 20%, which is why people experience stalls on genuine calorie restriction. There are numerous other issues that affect the metabolic rate: exercise, genetics, sex hormones, thyroid hormones, external temperature, illness, insulin, and nutrients like vitamin A, zinc, iodine, calcium, magnesium.

The study concludes: “Although our results strongly indicate that [the 17] patients referred to us for disturbances in body weight regulation were underreporting their food intake, we did observe one patient with a resting and total energy expenditure 25% below that predicted based on body composition. It is thus possible to have a modest reduction in energy requirements, and more research is needed to explore the underlying causes of a low resting metabolic rate in the presence of normal serum thyroid hormones.” It neither mentions nor explains the +/- 15% that is so important to most normal individuals, instead singles this patient out as being some sort of freak of nature, which is a distortion of fact.

The “modest reduction in energy needs” referred to is the whopping difference between me eating 1,800 kcal a day or eating 1,350 kcal a day.

Caloric control isn’t about a fine line (1 kcal over or under 1,800 would cause weight gain or loss), it’s a wide band, for which most people must transgress +/- 15% to see weight gain or loss. The occasional pat of butter is irrelevant.

This page has a slightly broader view:

Fat loss = 12 – 13 calories per lb. of bodyweight
Maintenance (TDEE) = 15 – 16 calories per lb. of bodyweight
Weight gain: = 18 – 19 calories per lb. of bodyweight

If I reduced my calories to 1,550 a day, I should lose half a pound a week, right? Well I don’t. If I increase my calories to 2,000 a day, I should gain half a pound a week, right? Well I don’t.

I lost 12 pounds in two weeks when I first went on Atkins. There is no way on this earth that 8-10 pounds of that was water weight. Sure, I ate less. But I didn’t eat THAT much less. At the start of my fat fast, I lost weight too quickly, then my weight loss slowed down to a crawl and I repeatedly plateaued on an average of 1,200 kcals per day. I went cold, and I had to add high-calorie days back in to get my weight to shift.

You must push beyond that 15% band to lose weight: sometimes people have a band of 20-30%, which makes life hell. But woe betide you if you push too far beyond the band, because your metabolism suffers long term.

As yet there are no studies to determine BMR variation in one individual during calorie restriction in a calorie chamber. So what evidence do we have?

Well, there are studies like this that show the effects of micronutrients on BMR. And in athletic women with menstrual disorders. Studies of fat free mass show big differences in BMR. Elderly Italians have a significantly lower BMR than matched elderly French, independently of the measured thyroid hormones (the French of course eat more fat, and Italians more carbohydrate). There are studies that show differences in BMR in acutely ill patients. And reductions in the BMR of mice on calorie restricted diets. And this study claims a reduction of BMR of 25% in fasting patients, but no change in those who eat a very low calorie diet, though thyroid hormones are changed in both groups!


Written by alienrobotgirl

18 April, 2006 at 2:23 pm

2 Responses

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  1. Are you sure that you have to restrict calories so drastically, now that you’re on failsafe? The last time you fat-fasted it was when you were still eating chemicals. Perhaps the elimination of salicylate, amines, sulphites, etc. will improve your metabolism (particularly salicylates)? You could try a 1400/day regimen to find out.p.s. I think I’m going to get in trouble on LCHF now for my latest response! haha.

    Mother Nuture

    18 April, 2006 at 4:53 pm

  2. I really don’t know how much I’ll have to restrict calories. I was hoping that my very moderate restriction last week would take a pound or half a pound off. I didn’t get through that 15% barrier. I didn’t lose any weight, in fact I’ve gone through some sort of horrible rebound and have weighed 8st 13lbs for the last two or three days.I think your response on LCHF was perfectly justified under the circumstances – it’s hard enough hearing “you’re lying about food” from thin people, let alone other fat people!

    Alien Robot Girl

    18 April, 2006 at 6:53 pm

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