> 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. If you don't consume enough protein, fat or carbohydrates to fulfill that energy need, then your body will get the energy from existing fat stores and will also scavenge from muscle under certain conditions. A small person living a sedentary lifestyle might get by on 800 calories a day, but most adults would eventual become emaciated. -Tad