Time-restricted eating boosts weight loss in adults with obesity, prediabetes

A recent study published in the journal Obesity suggests that time-restricted eating can lead to modest weight loss in adults with obesity, prediabetes, or diet-controlled Type 2 diabetes. Time-restricted eating, also known as intermittent fasting, involves consuming food within an 8- to 10-hour window each day. Led by Daisy Duan, an assistant professor of medicine at Johns Hopkins Medicine, the study examined whether restricted meal timing without calorie restriction could alter obesity-related factors like eating behavior, inflammation, and appetite hormones.

The study involved a predominantly female (92%) and Black (92%) cohort of adults aged 18–69 with obesity and prediabetes or diet-controlled Type 2 diabetes. Participants were randomly assigned to either a 10-hour time-restricted eating schedule (19 participants) or a 16-hour usual eating pattern schedule (20 participants). Both groups followed the same adapted Dietary Approaches to Stop Hypertension (DASH) diet, which is heart-healthy and limits red meats, high-fat foods, sugar, and salt intake.

The caloric intake for each individual was personalized to help maintain their starting weight. Meals were provided and prepared by the Johns Hopkins ProHealth Clinical Research Unit.

Before and after the study, participants provided fasting blood samples for measuring inflammation markers and appetite hormone levels, as well as completed the Three-Factor Eating Questionnaire, which gauges their interaction with and thoughts about food. The researchers tracked and compared physical and psychological changes over time between the two groups.

At the study's conclusion, both groups experienced similar and modest weight loss (median 2.7% for time-restricted eating and 2.5% for usual eating pattern). Additionally, participants reported increased restraint around food, reduced stress-eating, and overall lower hunger levels after the study period. However, the appetite hormones (ghrelin and leptin) and inflammation markers (C reactive protein, cortisol, and sRAGE) were comparable between the two groups, indicating no unique, body-wide health benefits specifically linked to time-restricted eating beyond weight loss.

Future research may explore how time-restricted eating influences weight loss maintenance among individuals who have already lost weight through other interventions, such as GLP-1 receptor agonists.