ASK THE GURU ARCHIVES – Daniel Duchaine

GURU: Why can some bodybuilders eat so many calories each day? If I eat over 2,500 calories a day, I get fat. Do these mega-calorie eaters have super-fast metabolisms?

Big bodybuilders have always confounded the scientists. I’ve known numerous top bodybuilders who actually eat at least 6,000 calories a day. Sure, they train hard, but the amount of energy expenditure isn’t all that enormous, not like an endurance runner or a bicycle racer. And if you bothered to find out the body temperatures of the big muscle guys, they aren’t usually over normal. So what’s happening with all the calories? There’s no magic going on here. Most scientists don’t often see human bodies over 250 lbs with less than 10% bodyfat. Fatter bodies at the same body weight don’t need as much food. Fat cells don’t use very much energy. Fat also is an excellent insulator. You should understand that body temperature is not only how much head is generated within the muscle cells. It’s also tied in to how much heat is radiated out into the air. When bodyfat is lowered into single digits and the skin is only about two to four millimeters thick, tremendous amounts of heat escape into the environment. If we could suddenly throw another 25 pounds of fat on a 250-pound lean bodybuilder, the energy requirements would lessen because more heat would be held in by the body. If you want to eat more food without getting fat, lower your bodyfat, so you become a better heat radiator. You may not be able to eat 6,000 calories, but then again, if you were 250 pounds and had 6% bodyfat, you wouldn’t be asking the question, would you?

GURU: I’ve gotten those thyroid tests that you recommended in your last letter. Here are the results: T3: 0.78, T4: 1.22, TSH 3.48. Would you explain the results to me? And by way, you were right, my morning body temperature was 97.2°F. Do I need thyroid and, is so, which type?

In my diet book, ::  BODYOPUS :: I’ve written several chapters on the specifics of body temperature, thyroid hormone, and how to optimize them. Usually, I would respond to this question personally rather than answer it in this column format, but the answers will be applicable to many, many readers, as thyroid levels will affect not only the quantity of calories you can consume in a day without getting fat but, more importantly, the quality of the calories consumed.

Let me fill you in on the woman who wrote me with the question above. Valerie is a female bodybuilder living in Paris. She has had a very hard time gaining solid muscular weight without gaining bodyfat. Her caloric intake is less than 2,000 calories a day and even with the use of various thermogenic drugs like ephedrine and clenbuterol, her bodyfat hovers around 15%, which for a bodybuilder, even a female one, is too high. I suggested that she go to her doctor and order up some blood tests, including the three thyroid tests, the results of which we just saw in her question.

Of the three hormones, the thyroid hormone is the only one that regulates body temperature. The other two are the noradrenalines and the prostaglandins. We all have various thyroid hormones circulating in the blood stream, but there is only one active one that actually binds onto the cells and imparts the various instructions to the cell. The first kind is Triiodothyronine (or the synthetic Liothyronine) T3 for short. Most of the thyroid that is produced and floating through the bloodstream is the nonactive thyroxine or T3 type, is converted from T4 with the use of an enzyme called 5′deiodinase. (Hint for the future: most enzyme names end with an “ase”.)

But wait, please don’t be scared off with all these long and unpronounceble words. The worst is over. Valerie had three thyroid tests done. This first on the list is the active T3 level. This value affects body temperature. Whenever a blood test result is given, the normal range of values is also given. The normal range (yes, even in Paris) is between 8 and 2.2. Valerie’s T3 level is .78. Whoa, it looks like the .78 value is not just low but off the normal scale. Why is it so low?

This is why we want to see the other thyroid values. Next on the list is the T4 amount. Valerie’s T4 value is 1.22, and it looks pretty normal, considering the usual range of values is between .70 and 1.90. The third test is the Thryoid Stimulating Hormone (TSH) test. TSH is manufactured by the pituitary, and it causes the thyroid gland to secret the other thyroid hormones. The TSH value here was 3.48, right in the middle of the .2 to 5.0 TSH normal range.

What have we learned? Valerie’s thyroid is adequately producing the nonactive T4 thyroid, but somehow, there isn’t enough of the thermogenic T3 one. Where is it going? As you learned a few lines back, the enzyme 5′deiodinase converts T4 to T3. Obviously, in Valerie, it’s not working very well. What we haven’t seen (because the test wasn’t performed) is that all the T4 was converted nto another non-active thyroid called reverse T3.

I wish we had some kind of stimulating enzyme drug or amino acid that would rev up this enzyme, but we don’t. So let’s look backwards to see how the enzyme inhibition happened.

In this particular case, the culprit was clenbuterol, the thermogenic agent Valerie was using. This is something I pointed out a few years ago. (Hold on, this whole thing still applies to you even though most of you will rarely use this non-FDA approved drug). A more common 5′deiodinase inhibition is from being on a low-calorie diet for awhile. That’s right; regular dieting, even without thermogenic agents, will eventually lower the body’s T3 levels. I think you know that evenutally just about all low-calorie diets stop working. The dieter gets stuck. To get the fat loss moving again, the individual has to once again lower calories even more. And remember, the more calories dropped, the more muscle lost. So when the dieter gets stuck, what’s happening? The T3 is lowered and the body temperature is lowered enough so that not as much food is needed to maintain body heat. The rough estimate I use is that every 1.5 degree (F) lost from the individual’s normal morning temperature indicates a 20% reduction of calories needed. The medical term of this T3 impairment is Euthyroid Sick Syndrome.