Your Metabolism Has Slowed Down
Like so many other body functions, your calorie-burning engine takes a dive as you age, says Moon. For the average guy, that's about fewer 10 calories per day with every year according to the Mayo Clinic. Those 10 daily calories sound small, but add up to about a pound of annual weight gain. Even if the food you consume is lean and nutritious, it boils down to math: Take in more calories than you burn off, and your stomach is not going to budge. Calculate the daily caloric needs for your age here. Then, to reduce your gut, make sure your intake is below that benchmark. Start with 100-200 calorie deficit per day (factoring in exercise) so that you're not starving. If you have substantial weight loss goals, more than 10 pounds, work up to a 400-500 calorie deficit per day.