By: Pallavi Vathiar. Practicing Clinical Nutritionist, Mumbai.
According to your circadian rhythm, night time is for resting, not eating.
When researchers tracked the eating habits of 52 adults, they found that those who ate past 8 p.m. consumed more total calories than earlier eaters. The extra calories consumed by late eaters could lead to weight gain over time (1).
By not eating after 7 p.m., you may train your body to become more efficient at burning fat. According to a study in 2017 at Pennsylvania, frequently eating late at night anytime between 7 and 11 p.m., can affect your body’s metabolism of fat. You’ll tend to burn fat more slowly (2).
Eating something at night, after your normal dinner hour or extending late into the evening, can cause the body to store those calories as fat rather than burn it as energy. This is because the hormone ghrelin, which stimulates appetite, peaks earlier in the day, while the hormone leptin, which keeps you satisfied, peaks later in the day. This indicates that eating early helps you stay satisfied longer, according to the Perelman study (2).
Circadian Rhythm and Meals
Your circadian rhythm is basically your 24-hour internal clock. For most adults, there’s a drop in energy from 2 a.m. to 4 a.,m. and again from 1 p.m. to 3 p.m., usually just after lunch. Known as your sleep-wake cycle, it’s controlled by your pituitary gland, and it’s what tells you you’re sleepy (3).
According to a study of American Journal of Clinical Nutrition, they found that when participants ate a meal within four hours of bedtime, the food they ate gave off a lower energy response than in those who ate earlier. The study also found that when a late bedtime becomes the norm, because of work, going to college or other reason, more food tends to be eaten during the last meal of the day. That can lead your body to store more fat, and cause you to build up more fat reserves (4).
Small Snack Before Bed-time
Eating a small snack before bedtime, however, may be less consequential. Researchers who conducted a study in 2015 found that eating a snack before bedtime, totaling 150 calories or less, typically doesn’t cause a problem. This is most notable for athletes who may get hungry more often or diabetics who need to control their sugar levels (5).
In obese women, eating before sleep has been shown to improve morning appetite but also increase insulin resistance. However, the addition of exercise training for four weeks appears to eliminate any adverse effects of nighttime feeding in this population and has been shown to improve some indicators of cardiovascular health (5).
In other diseased populations (e.g., GSD, T1DM), eating before bed is actually required for survival. However, management with individually tailored nighttime feeding protocols may optimize their clinical outcomes (5).