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Okay, sorta got it. I was using the old fallacy that skeletal muscles were consider as "stores". Plus, I confused the discussion with the mention of ATP.

What I still don't understand is at what point does the body start the cannibalization of skeletal muscle. Is that what body-building "over-training" is about - simple lack of protein vs exercise? Using the amino acids in other muscle groups to repair the damage of the muscles just exhausted? Sort of a self-defeating Peter paying Paul cycle? So more protein will correct this cycle? Right? At what point with additional protein are you adding fat plus muscle? That's the tough one for us amateur weight lifters.

I also don't get why nutritionists suggested 5 or more small meals (Weight Watchers) rather than 2 or 3 meals of comparable calories and macro-nutrient ratios. Although with your burn formula, I do now better understand why Atkins works so well. Thanks for the feedback. What a complex system our bodies are and no wonder there has always been so much contradicting info out there to us laymen.

What I still don't understand is at what point does the body start the cannibalization of skeletal muscle. Is that what body-building "over-training" is about - simple lack of protein vs exercise? Using the amino acids in other muscle groups to repair the damage of the muscles just exhausted? Sort of a self-defeating Peter paying Paul cycle? So more protein will correct this cycle? Right? At what point with additional protein are you adding fat plus muscle? That's the tough one for us amateur weight lifters.

If you've radically increased your lean body mass in the form of skeletal muscles, you'll increase the required energy intake to fuel that muscle and stay at an energy balance where you won't gain fat. If you decrease your energy intake and maintain the same level of energy expenditure (not only resting metabolic rate, but large muscle activity), you'll make up the difference required from stored body fat. After that, the energy deficit will have to be made up from skeletal muscle. Also, if you've built up your muscles and increased muscle tone to a high degree and just stop the physical activities that led to that state, you'll lose both muscle tone and muscle mass. I don't know what the signaling pathways are for that, but it's not desirable from a survival standpoint to continue to expend large amounts of energy to maintain a level of musculature that is not being used. If you continue energy intake at the level needed by that level of muscular development, then you're going to be in energy surplus and will 1. lose muscle mass and 2. gain fat mass. That's probably where the idea came from that not using your muscles leads them to turn into fat. It's known for certain that moderate physical activity, an hour or so several times a week, even as light as brisk walking, is very helpful in maintaining weight loss. As far as the supply of amino acids for muscle repair goes, with a typical American diet you'll almost never be at a loss for adequate amino acids for muscle building and repair. You have more proteins in your diet than you need for protein synthesis plus your body is continuously breaking down proteins of all kinds and providing a pool of amino acids for continuous protein synthesis. Look at an 80 lb 13-year-old growing to a heavily muscled 160 lb 17-year-old. In four years he doubles his body weight and it's just by what he's getting in his everyday diet. You, on the other hand, are not anywhere near those kinds of demands for energy and growth. Your main problem as an adult is avoiding eating too much and getting an increase in fat mass.

I also don't get why nutritionists suggested 5 or more small meals (Weight Watchers) rather than 2 or 3 meals of comparable calories and macro-nutrient ratios. Although with your burn formula, I do now better understand why Atkins works so well.

If the kilocalorie content is the same, you could eat 1 meal or 15 small meals over the course of a day and it won't make any difference at all. There will be no difference in weight gain or loss except to the extent you over or undersupply your energy requirements. The larger number of smaller meals has the benefit of assuaging your hunger. People who eat only a couple of meals a day or who go for a long time between meals are more likely to overeat because they get so hungry. Once you start eating something, it takes a while for satiety to kick in. It's very easy to exceed what you need just by eating a whole lot very quickly. But regardless, your body is so efficient that it will absorb almost the entire nutrient content of what you eat whether you need it or not (unless, of course, you've had part of your small intestine resected). I remember discovering this when I was a teenager in Brazil when I was invited to eat at a missionary's house. I was so nervous and ate so slowly (that is, at the rate the others were eating, not my typical teenage jet intake) that after about 20 or 25 minutes I was amazed that I was no longer hungry in spite of having eaten so little. I had eaten at a rate at which my satiety signals weren't outrun by my rate of eating. This also calls to mind my nephew who, when he was little, was pretty hefty. I asked him once, "How do you know when you've eaten enough?" He replied, "When it hurts."

Thanks for the feedback. What a complex system our bodies are and no wonder there has always been so much contradicting info out there to us laymen.

Sure! The body really is fearfully and wonderfully made.

BTW, I should have used a plate of pasta as a contrast with saltine crackers for differences in glycemic index. A baked potato is about the same as a cracker, ~100.