Do You Have 20 Minutes a Day to Lose Weight?

After a while you can do it in 15 minutes.

Posted Mar 29, 2019

New research has demonstrated that spending as little as 20 minutes a day could result in “clinically meaningful weight loss.” With repetition, the participants in this study were able to cut down the time required to 15 minutes per day and still lose weight. They weren’t doing a high-intensity workout for 20 minutes and they weren’t meditating before each meal or following some esoteric diet. Rather they were just logging in to a study website and recording their daily eating.

In a study of 142 participants (90 percent female, 23 percent African-American) Dr. Jean Harvey and her colleagues found that self-monitoring needn’t be difficult or time-consuming. In a 24 week, online behavioral weight control program participants logged in to a website and recorded their intake. They received feedback on total calories consumed so far that day and were given the number of calories they could consume and still reach their daily goal. They were encouraged to monitor their intake throughout the day and plan their eating for the rest of the day. 

The researchers found that weight change was significantly correlated with the amount of time spent on the website. After six months virtually all of the participants who had significant weight loss were still self-monitoring and the successful losers monitored at least two or three times a day rather than just at a single sitting. 

When I lead weight loss groups and suggest that participants record their daily eating sometimes I hear objections like “It takes too much time,” “It’s too hard” or, “I just forget” but these rationales are rarely accurate. This study shows that it doesn’t take a lot of time and previous research has shown that scrupulous accuracy isn’t necessary for successful weight loss. What matters is frequency and consistency of monitoring, not time-consuming, finely detailed recording. 

 If there are several free smartphone apps that are easy to use (e.g., Lose It, My Fitness Pal), and precision isn’t required, and it only takes 20 minutes a day so why are there objections to self-monitoring? I suspect that self-monitoring increases awareness of food choices and that might result in feelings of guilt and self-recrimination when the inevitable slip occurs. Instead of viewing self-monitoring as a tool to judge self-discipline it should be thought of as a method to identify problem areas that need to be addressed. There’s no need to feel bad, self-monitoring is just a method to gather information to help change habits so it’s a worthwhile investment of 20 minutes.


Harvey, J., Krukowski, R., Priest, J. & West. D. (2019). Log often, lose more: Electronic dietary self-monitoring for weight loss. Obesity, 27, 380-384.