Most men need to eat 6-10% more calories per pound of body weight than their female counterparts in order to maintain muscle mass and normal body functioning. And because men tend to have higher total muscle mass, many high-mileage male runners have difficulty maintaining or gaining weight. On the flip side, men who run less weekly mileage often find it all too easy to pack on pounds. What is the happy medium? Eating three balanced meals and two healthy snacks daily is important for men who run. If you're trying to gain a few pounds or just maintain your current weight, look for healthy, calorie-dense foods such as avocados, olives, nuts, and nut butters. If you're trying to lose weight, load up on non-starchy veggies, and snack on fruits and low-fat dairy to maintain energy and keep hunger at bay.