I constantly find myself eating random food in my dorm when I’m doing homework really late at night. My dad always used to tell me to stop eating after 10 pm – seems that I brought this bad habit from home – and he gave a vague explanation saying that the body turns food into fat after a certain hour at night. It appears that a study has finally found the mechanism behind this fact that I had hoped was a myth.

A study at the Salk Institute of Biological Sciences decided not to look at the question of what to eat but when to eat. They looked at four groups of mice: one group with 24 hour access to high-calorie food, one group with 24 hour access to less fatty foods (control for 24 access mice), one group with 8 hour access to high calorie food, and one group with access to less fatty foods (control for 8 hour access mice). The point was to measure how mice, both with access to the same amount of calories in high-fat foods, could change based on 24 hour or 8 hour eating schedules. After 100 days, the researchers looked to see the differences between the two groups of mice.

The mice with 24 access to the food had more health problems than the 8 hour group, “weight gain, high cholesterol, high blood sugar, liver damage, and even motor problems when put to an exercise challenge” (Walton). The mice with restricted access weighed 28% less than the higher-fat mice. Satchidananda Panda, the leader of the study, concluded, “Every organ has a timer…When we eat randomly, those genes aren’t on completely or off completely” (Walton). This study was done in 2012, and I feel there are few 3rd variables and reverse causation is ruled out by first principles (the food came first then the health problems, both problems didn’t occur simultaneously).

A similar study was made in 2013 that found mice on this disrupted eating cycle were less responsive to insulin when a dim red light kept the mice up all night. Their sleep cycles and eating cycles were off, so the insulin didn’t break down sugars creating fat. This article did not give full details on the study itself, like how it was conducted or what the exact results were, which makes this source a little unreliable (even though it was reproduced on the Today.com). However, the study adds to the original study of 2012 on the mechanism behind the weight gain.

So in conclusion, the study found it was fine to eat on a regulated schedule in order to give the metabolism a time to rest during the night. However, it doesn’t suggest that only eating during an 8 hour span is the healthiest way to go – the food must also be healthy, the same way eating healthy foods late at night isn’t entirely healthy.