If obese people eat only during certain hours of the day without counting calories, their body may handle insulin better than if they do nothing—but it’s not any better than just eating fewer calories, and we need more research to be sure.

If you're an adult with obesity and you eat only during certain hours of the day for a year, it won't make you more likely to have bad side effects than if you just eat fewer calories every day.

If you're overweight and eat only between 8 a.m. and 4 p.m. for a year, you’ll lose about 8 kg — but if you just eat fewer calories without worrying about when you eat, you’ll lose about 6.3 kg. The difference is so small that it doesn’t really matter which method you pick — cutting calories is what matters most.

If you eat only between noon and 8 p.m. without counting calories, you’ll lose about the same amount of weight over a year as someone who cuts their daily calories by 25%—the difference is so small it could just be due to chance.

If obese people only eat between noon and 8 p.m. every day—without counting calories—they tend to lose about 4.6 kg (over 10 pounds) in a year, just by changing when they eat, and not by eating less.

When obese women only eat during a short window each day (without counting calories), they lose less weight and gain more belly fat than when they eat fewer calories overall.