A 12-week Johns Hopkins Medicine study reveals that limiting eating to a 10-hour window results in slight weight loss among adults with obesity and prediabetes, adding to mixed evidence on meal timing benefits.
A Johns Hopkins Medicine study has found that time-restricted eating can produce modest weight loss in adults with obesity who also have prediabetes or diet-controlled type 2 diabetes, even when overall calorie intake is held steady. The research, published in the journal Obesity, adds to a growing but mixed body of evidence on whether narrowing the daily eating window offers benefits beyond simple calorie reduction.
In the 12-week trial, participants were randomly assigned either to a 10-hour eating window or to a more usual 16-hour pattern. Both groups followed the same adapted DASH diet, a heart-healthy eating plan that limits salt, sugar, red meat and high-fat foods, and both were given meal plans designed to keep body weight stable. Despite that, the people in the time-restricted group lost a median 2.7% of body weight, while those in the comparison group lost a median 2.5%, a difference the researchers said was small.
The study, led by Daisy Duan, an assistant professor of medicine at Johns Hopkins, also found that both groups reported eating in a more controlled way, feeling less driven to eat in response to stress and experiencing less hunger overall. However, blood tests did not show meaningful differences between the groups in appetite hormones or inflammation markers, suggesting that the main effect of the eating schedule may be modest weight loss rather than a broader metabolic shift.
That finding sits alongside earlier studies that have pointed in different directions. A 2022 randomised trial in JAMA Internal Medicine reported that early time-restricted eating produced more weight loss than eating across 12 hours, while a 2023 study in JAMA Network Open found no significant weight advantage when calories were kept equal. Other trials, including research in Obesity and Nutrition & Diabetes, have likewise produced mixed results, with some showing small benefits and others finding little difference from more usual eating patterns. Johns Hopkins researchers say they now want to look at whether time-restricted eating can help people maintain weight loss achieved through other approaches, including GLP-1 medicines.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
