Time-Restricted Eating and Weight Loss in Prediabetes

Trial Compares Time-Restricted Eating to Usual Schedules

Time-restricted eating (TRE) produces modest weight loss in adults with prediabetes or diet-controlled type 2 diabetes. A 12-week randomized trial led by Johns Hopkins Medicine found that a 10-hour daily eating window matched a standard 16-hour usual eating pattern (UEP). The study appeared in the journal Obesity with support from the National Institutes of Health (NIH) and the American Heart Association (AHA).

Thirty-nine adults finished the intervention. The cohort was 92 percent female and 92 percent Black, with participants ranging from 18 to 69 years of age. Researchers assigned 19 adults to the 10-hour window and 20 adults to the 16-hour schedule.

Provided DASH Meals and Weight Maintenance Calories

All study participants received fully prepared meals from the Johns Hopkins ProHealth Clinical Research Unit in Baltimore, Maryland. The kitchen provided an adapted Dietary Approaches to Stop Hypertension (DASH) diet. This pattern limits red meat, high-fat items, sugar, and sodium.

Research dietitians calculated personalized calorie levels to keep each person at their baseline weight. This setup isolated meal timing from calorie deficits. Lead author Daisy Duan, M.D., noted that previous fasting studies often included unintentional calorie cuts.

Time-Restricted Eating Yields Similar Weight Loss and Restraint

Time-restricted eating yielded a median weight loss of 2.7 percent over the 12-week intervention. Participants on the standard 16-hour schedule dropped 2.5 percent. The weight reduction occurred in both arms even though meals were calibrated for weight maintenance.

Eating behaviors improved in both arms on the Three-Factor Eating Questionnaire. Participants reported greater restraint around food choices. They also reported lower susceptibility to hunger and a reduced tendency to eat during periods of stress.

Hormones and Inflammation Remained Unchanged Between Groups

Fasting blood tests showed that time-restricted eating produced no distinct changes in appetite hormones or inflammatory markers. Levels of ghrelin and leptin were comparable between the two groups at 12 weeks. Markers of inflammation also remained similar.

C-reactive protein (CRP), cortisol, and soluble receptor for advanced glycation end products (sRAGE) did not separate the arms. These findings suggest that metabolic shifts stemmed from weight loss rather than independent biological clock effects.

Discussing Time-Restricted Eating with a Clinician

Time-restricted eating provides a structured framework that may help people manage eating behaviors without counting calories. In the United States, 100 million adults live with obesity and 115 million have prediabetes. Both groups face higher risks for high blood pressure, heart attack, and stroke.

The trial was small and tested fully prepared meals in a tightly monitored clinical environment. Results might differ when people purchase and prepare their own groceries at home. Talk with your clinician about time-restricted eating before adjusting your meal timing or changing medication routines.