Fasting three days a week may be more effective — and more doable — than counting every calorie, new research suggests.

A team at the University of Colorado tracked 165 overweight adults for a year, comparing two approaches: daily calorie restriction versus a 4:3 fasting plan, where participants drastically cut calories on three nonconsecutive days per week and ate normally the rest of the time.

Those in the fasting group didn’t count calories on their nonfasting days but were encouraged to eat healthfully and mindfully.

By year’s end, daily calorie cutters had shed 5% of their body weight, while the fasters lost an average of 7.6%, which is roughly 17 pounds. Dropout rates were also lower for the fasting group, and 58% hit the benchmark of at least 5% weight loss versus just 47% in the traditional dieting group.

“It was surprising and exciting to me that it was better,” Dr. Victoria Catenacci, co-lead study author and an associate professor of endocrinology at the University of Colorado School of Medicine, told the New York Post.

“It’s just another strategy for people to consider,” she said of the results of the study, released Monday. “It’s really hard to restrict calories every day.”

The typical American consumes well over 3,000 calories daily — nearly double the minimum needed to maintain weight — much of it from sugar, refined grains and processed snacks, according to the Agriculture Department.

Obesity affects more than 40% of U.S. adults, contributing to surging rates of diabetes, high blood pressure, and heart disease, the agency contends.

Some fasting regimens ask people to abstain every other day or twice a week, but researchers say those extremes are too harsh or too mild to make a lasting difference.

“With this 4:3 approach, where they’re fasting three days a week (which are flexible and can be worked around a personal schedule), it might be a middle ground where they feel like they can adhere to it, and it’s feasible to implement in their daily lives,” Dr. Danielle Ostendorf, another of the study’s authors, told the Post. “It also produces a significant calorie deficit across the week.”

Participants in the fasting group also saw more improvement in key health metrics like blood pressure, cholesterol and blood sugar levels, though the study wasn’t large enough to draw firm conclusions on those fronts.

“With previous studies, we just hadn’t seen that intermittent fasting was any better than calorie restriction,” Dr. Ostendorf said. “But this 4:3 plan might be the sweet spot.”

Researchers are testing the method in other populations, including breast cancer survivors, and plan to develop clinic-friendly versions of the program.

“We need more tools in the toolbox,” Dr. Ostendorf said. “This one shows real promise.”

• Emma Ayers can be reached at eayers@washingtontimes.com.