HMN 2026: How to Try intermittent fasting for weight loss

Yo-yo dieters who struggle to lose weight and keep it off may achieve better results by following an intermittent fasting diet, rather than traditional calorie counting. An Adelaide University study focusing on the psychological aspects of both intermittent fasting and calorie restriction compared the effects the diets had on eating behaviors, mood, sleep and quality of life. The research is published in the journal Clinical Nutrition.

Although both diets led to similar amounts of weight loss, those on the fasting diet didn’t feel as though they needed to make major changes to their eating behaviors—such as monitoring overeating or counting calories—to lose weight.

This contrasts with the calorie restriction diet, where participants reported consciously having to think about restricting their food intake and avoiding overeating. That improved control accounted for 15% of their weight loss.

“While many diets can result in weight loss, they may be difficult to stick to, and this makes keeping that weight off long term more challenging,” said Professor Leonie Heilbronn from Adelaide University’s School of Medicine and the South Australian Health and Medical Research Institute.

“The results of our study indicate intermittent fasting could offer an alternative pathway for people who find conventional dieting challenging.”

More than 200 people with obesity were involved in the 18-month trial, which saw participants split into three diet groups—intermittent fasting, continuous calorie-restricted and standard care.

The intermittent fasting group was required to consume 30% of their energy needs between 8 a.m. and noon on three nonconsecutive days each week, followed by a 20-hour fast. On nonfasting days, they were able to eat their regular diet.

Those on calorie-restricted diets were limited to eating 70% of their usual diet, while the remaining participants followed standard diets but were given healthy eating guidelines.

Participants on both calorie-restricted and intermittent fasting diets lost around 7 kilograms (15.4 pounds) in six months, compared with just 2 kilograms (4.4 pounds) lost by those on the standard diet. They also reported improved levels of depression and well-being—even on fasting days.

The findings suggest calorie restriction and intermittent fasting diets may drive weight loss through different psychological and behavioral pathways.

“Psychological and behavioral effects have a major influence on people’s abilities to adhere to diets. Intermittent fasting may help people achieve weight loss through ways that are less dependent on consciously restricting intake,” said Heilbronn.

While intermittent fasting has become increasingly popular, relatively little is known about its long-term psychological and behavioral effects compared with standard dieting approaches.

“Future trials should be designed to identify individuals who struggle to improve eating behaviors, as they may do better with intermittent fasting diets, enabling more personalized weight management,” said Heilbronn.

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