Some experts claim that eating at night can make you gain weight. One study found that mice who were fed later in the day gained more weight than mice fed the exact same number of calories earlier in the day.
However, many nutritional experts argue that a calorie is a calorie, no matter what time of day you consume it. Their argument is that the only way to gain weight is to consume more calories than you burn, and losing weight is a result of burning more calories than you eat.
Which is correct?
The problem may have less to do with when you eat than what you eat. Late-night snacks tend to consist of large portions of high-calorie foods. Many after-dinner treats are eaten in front of the TV or computer, making it more difficult to monitor portion sizes. In these cases, weight gain is likely not a result of eating at night, but of overeating without enough physical activity to burn off the excess calories.
In addition to being conducive to poor eating habits, eating too close to bedtime can cause indigestion and dangerous nighttime acid reflux.
Instead of avoiding nighttime snacks all together, dieters may be better served by sticking to healthy, portion-controlled snacks. Also, focus on eating every three to four hours during the day to stabilize your blood sugar and avoid late-night junk food cravings.