Dietary guidelines and caloric percentages
Q. I really appreciate the dietary guidelines that you publish from time to time, but my wife and I find it hard to do the math in a busy supermarket. Can you give us targets that are easier to use than "percentages of daily calories"?
A. I understand the problem, and I'll try to help. The reason we use percentages of daily calories is that dietary needs vary from person to person. But let's do the math for a hypothetical person, and then give you a template so you can run the numbers for yourself.
The first step is to determine how many calories you need for an average day. As a rough guide, a sedentary person needs about 13 calories per pound of body weight to maintain a steady weight; moderate physical activity boosts the daily quota to 16 calories a pound, vigorous exercise to 18 calories a pound each day. For a 175-pound man with a moderate exercise schedule, that comes to 2,800 calories a day.