Calories, Not Meal Timing, Key to Weight Loss

A study finds that it’s caloric deficit that spurs weight loss, not any change in meal timing.

When it comes to the battle of the bulge, we have more evidence that calories are king. A head-to-head trial of a calorie-reduced diet and a time-restricted eating diet, published in Annals of Internal Medicine, found no difference in weight loss or other health indicators. For the study, 41 people with obesity and pre-diabetes were assigned to one of two eating regimens:

• Half of them engaged in time-restricted eating, where they ate only between the hours of 8 a.m. to 6 p.m. and consumed the majority of their calories before 1 p.m.
• The other half of the participants ate in a more regular pattern, eating anytime between 8 a.m. and midnight, and taking in most of their daily calories after 5 p.m.
• Critically important to the study was that everyone received prepared meals with identical macronutrient and micronutrient compositions and identical daily calorie counts.

Individuals on the fasting regimen lost an average of just over 5 pounds, while those who ate on a regular schedule lost a bit more; about 5.7 pounds (a non-significant difference). The team also saw no significant difference in blood sugar changes between the two groups. So, even though fasting diets are all the rage, if someone simply cuts their daily caloric intake weight loss can occur regardless of when food is eaten, the study authors concluded. But if someone finds it a hassle to constantly track calories each day, a fasting diet could still be a good option since fasting naturally reduces calories to levels that can trigger weight loss.