A. Eating more calories than you use all day leads to weight gain; eating fewer leads to weight loss. So, in theory, no matter when you eat them, as long as the number of calories you eat each day matches how many you burn, you won’t gain weight.

But some research has shown that way that that food calories are distributed may affect hunger—and that, in turn, could affect weight gain. A 1999 study in the journal Appetite found that when lean, healthy men spread their meals evenly throughout the day—as opposed to eating larger meals more infrequently—they were less hungry. Other studies have shown that people who skip breakfast, or who delay eating earlier in the day, are more likely to binge later.

Going for long periods without eating creates a state where the body is low on fuel. Metabolism may slow to preserve energy, and the body may be more sensitive to the calories that come later—it may be more likely to store those calories as fat and not use them. Irregular eating usually leads to eating larger meals to make up for the energy deficit. A big meal may overload the body's capacity to use those calories, and the extra may be more likely to be stored as fat.

While a highly-active person may be better equipped to handle larger meals because they are more likely to burn off excess if they overeat, even athletes show differences in body composition according to how they eat throughout the day. A 2000 study in the journal Medicine & Science in Sports & Exercise looked at the eating patterns of 62 female college athletes (elite-level gymnasts and runners). The researchers found that when the women in both sports ate erratically creating large energy deficits throughout the day (that is, they went for long periods without eating), they were more likely to have higher body fat percentages compared to the women who ate more regularly. This was true in both sports, and none of these athletes were overweight.

Since the body slows down in the evening, calories consumed at night may be more likely to be stored rather than used. Not only is a person less active, but all cells operate according to circadian rhythms, or fluctuations in their patterns of activity throughout a 24-hour period. Body processes—such as gut motility in digestion or the absorption of nutrients from food—also seem to operate on a kind of body clock showing decreased activity at night. But there do not appear to be studies that prove that if you eat past a certain time you will gain weight because of it.

Irregular eating is probably more of a problem than night eating. People who skip breakfast often shift their caloric intake to later in the day, eating the majority of their daily calories at night. Many obese people display eating behaviors that often involve skipping breakfast. For people who eat most of their daily calories later in the day, when they stop eating in the evening, they may experience weight loss. It’s easy to assume that it’s because eating at night is more fattening. But it may simply be that they are cutting calories, or dieting, by limiting their evening eating.

If you are eating healthful, regular meals and snacks during the day, a late meal probably won’t be a problem if you keep the meal size sensible. If you feel stuffed by the time you are crawling into bed, you may have gone too long without eating, then binged.

Avoid eating an overly-large dinner by eating a larger lunch. Make sure to snack on something every three to four hours. If you can nibble on nuts or fruit while you’re at work, you are likely to come home less hungry and will be able to eat a smaller meal.

Reproduced from MSN Health & Fitness by Martica Heaner, M.A., M.Ed.