On Wed, 24 Nov 2004 11:27:09 -0800, Tad Glines <[log in to unmask]> wrote: >> Ken Stuart wrote: >> Subject: Re: How many calories do we really need? >> >> Zero. >> >> However, we do need (very roughly) about 100 grams of protein a day, >> and about 40 grams of fat a day is helpful, too. > >A Calorie is a measure of energy contained in a food item. 100 grams or >protein contain about 440 Calories. 40 grams of fat contains about 360 >Calories. That's a total of 800 Calories. > >One Calorie (with a capital 'C') is equal to 1000 calories (with a lower >case 'c') which is equal to 4182 Joules. > >All are measures of energy. You body's daily energy needs are determined by >genetics, activity level and muscle mass The point is that it is not that simple. The human metabolism does not look for "energy" and "calories". Instead, it runs a variety of chemical reactions. Some of these reactions require amino acids, some require lipids, some require glucose. They are not interchangeable. In the 1950's, a researcher (Peatwick, I believe?) put three groups of people on three different diets, each of which contained 1000 calories. One was 1000 calories of protein, one was 1000 calories of carbohydrates, and one was 1000 calories of fat. The three groups lost differing amounts of weight on these diets - something which thousands of "experts" have ignored *after* the research was done, and continue to prescribe certain numbers of "calories". -- Cheers, Ken