If you want to lose weight, then you need to fast longer. The problem is Americans eat for hours. Not only that, a good portion of the daily caloric intake is eaten at night.
Salk Institute researchers conducted a study participated by at least 150 volunteers in San Diego area. These people are healthy, are not on a diet at the time of the study, and don't have shifting schedules. Using a smart phone app, they took pictures of the food they ate during the day including the times they were consumed.
Based on the analyses, participants ate for a very long period of time. Moreover, less than a fourth of their total daily calories were eaten before noon while about 30% were consumed past dinnertime.
About 10% of the volunteers ate an average of 4 times per day. Frequent eaters consumed food for about 15 times. Below 10% fasted for around 12 hours.
When it comes to calories, 12% of the average calorie intake among the participants were consumed past 9:00 p.m. But based on the body weight of the volunteers and the amount of calories they need to maintain it, volunteers were actually consuming more calories if they ate past 6:36 p.m.
The initial study shows that despite believing they are eating only three square meals a day, the reality is it might not be true. Explaining this issue, the researchers cite how erratic eating patterns and eating late at night can alter the body's metabolism, which is dependent on its own internal clock.
In another related study, the same researchers used the same phone app to determine if it can help promote weight loss through a more consistent eating time. The volunteers, who were overweight, were asked to fast between 8 and 11 hours and do it consistently for the next 16 weeks. The participants averaged an 8-pound loss during the period and were able to maintain it a year after.
It isn't clear how they lost weight since they didn't alter their eating habits, but they believe that since they're fasting longer at night, they ate fewer calories. They also had longer and better sleep, and sleep could impact metabolism.
The study is published in Cell Metabolism.