by jpowell » Fri Jun 29, 2012 11:13 pm
(Sorry: OT in that I don't know anything about shakeology, I haven't and probably won't use the product)... but I felt I had to but in with my 2c on the more tangential side of this thread...
Curious if there is any scientific evidence at all for a steadfast belief in constancy of food calorie equations, or if its just one of these popular nutrition/exercise memes that have become true rather through enough people repeating them, and a general superficial plausibility. I've never found any evidence and when you really think about what's involved in it being true, seems kinda hard for me to imagine at least the strong case/claims.....
You people do realize that the "calories in" various foods are not even their actual total potential chemical energy to start with, right? Nutritionists know that some types of carbohydrates are converted to energy not at all by humans, some minimally, some very variably and others well, so they use rough approximations based on possible "typical" processing. Then there's the extent to which they body can use protein as energy if it absolutely must (rather than only for bodily functions), which is surely non-zero but also quite controversial, and some of the fat content is not used for energy but other bodily functions too! Finally, the structure of food, even how it has been prepared, probably affect how much is really digested and used.... and it doesn't seem unlikely to me that more energy would be extracted from processed foods or, rather, less from whole foods, and less from raw vs cooked foods). Where does this leave you with energy in vs energy out... well if you start detailed measurements of the chemical potential energy of all bodily excretions as well as food, and you make the incredibly unlikely assumptions that they are invariant with other aspects of dietary composition, timing of when you eat food, exercise and other individual factors, together with the incredibly unlikely (i.e. contrary to probably a large body of exercise science) assumptions that metabolic rate is fairly invariant to diet and lifestyle factors, then you can still approximate energy expenditure through activities plus a basal metabolic rate and make some kind of meaningful energy balance calculation. Even then, conservation of calories can't correspond DIRECTLY to your physical weight.... since fat contains much more calories per gram than proteins (muscle, skin, ligaments, etc), and there are at least 3-4 different types of water weight that contain negligible calories per gram (and have different advantages, disadvantages and reasons to each other).
There are, of course, parameters. Certain patterns of activity require certain amounts of energy as a minimum and, all other things being equal or, in an extreme case, even if they are not, the more you eat, the bigger you can, even must, become (fatter, or larger muscles, depending on other factors) ... but those statements are so watered down and obvious as to be almost meaningless.
