Time-restricted eating (also called intermittent fasting) is a popular weight-loss strategy. A randomized controlled trial has found it only works to reduce weight if combined with lower calorie intake.
All meals and snacks were provided for 41 adults with obesity and prediabetes (or diet-controlled type 2 diabetes) for 12 weeks. Most participants were women, 93 percent were Black, and the average age was 59. One group ate the prepared meals in a 10-hour period, with 80 percent of their calories consumed before 1:00 p.m. The other group followed what the researchers called a “usual eating pattern,” with meals spread over 16 hours or less and 50 percent of calories consumed after 5:00 p.m. Each participant was offered the number of calories calculated to meet their daily needs, and participants were instructed to eat at specific times of day and finish all the food provided.
While both groups lost a small amount of weight, there was no significant difference between the two. This suggests that weight loss originally reported with intermittent fasting results from reduced calorie intake. In other words, it appears some people eat less when they have fewer hours in which to eat. Numerous studies have found that intermittent fasting is as effective, but not more so, than traditional calorie cutting. If you would like to try intermittent fasting, make healthy food and beverage choices and keep an eye on your portion sizes to ensure you are eating fewer calories than you typically would.