Time-restricted eating, also known as intermittent fasting, produced similar weight loss results to traditional calorie counting in adults with obesity, according to a small study.

Obesity is a major health issue, affecting millions globally. Many traditional weight loss diets involve counting calories, which can be cumbersome and difficult to do well.

Time-restricted eating, without calorie counting, has become a popular weight loss strategy because it is simple to do. However, whether it’s effective in producing weight loss, especially beyond the short term, is unclear.

Researchers from the University of Illinois, Chicago, studied 90 adults with obesity to determine whether intermittent fasting or calorie-restricted eating would be more effective for weight control and cardiometabolic risk reduction.

The small randomised controlled trial, published in Annals of Internal Medicine, found that participants who engaged in 8-hour time-restricted eating had improved insulin sensitivity compared to those in the control group who ate their calories any time over 10 or more hours a day.

Participants were randomly assigned to 1 of 3 groups: 8-hour time-restricted eating (eating from noon to 8 p.m. only, without calorie counting); calorie restriction (reducing 25 per cent of their calories daily), or no change in calorie consumption, with eating taking place over 10 hours or more throughout the day.

Both the time-restricted eating and calorie-restriction groups met a dietician regularly. The researchers found that participants who engaged in time-restricted eating ate 425 fewer calories per day than the control group and lost about 10 more pounds than the control group after one year.

The calorie-restricted group ate 405 fewer calories per day and lost about 12 more pounds after one year. Participants showed high adherence to both interventions.

Access to dieticians likely helped participants in the restricted eating group make healthier food choices, said authors of an accompanying editorial from the University of Colorado School of Medicine.

They believe the results of this study can help guide clinical decision-making partially by taking individual preferences into consideration, rather than just choosing a diet that may be more effective.

They also emphasised that the results of this study highlight the substantial individual variability in weight loss using these interventions and that further research is needed to determine who would most benefit from each of these interventions.