A new study from Johns Hopkins University challenges the notion that when you eat is more important than what you eat for losing weight. The findings suggest that while time-restricted eating, a popular form of intermittent fasting, can help people eat fewer calories and lose weight, the timing of meals itself may not be the key factor.

What the Study Showed

The researchers divided 41 adults with obesity and prediabetes into two groups:

• One group could only eat between 8 a.m. and 6 p.m., with most calories consumed in the morning
• The other group had a wider eating window of 8–12 am, with most calories eaten later in the day

Both groups ate the same total number of calories per day based on their estimated needs. After 12 weeks, the two groups lost a similar amount of weight on average. There were also no significant differences between the groups in measures like blood sugar, waist size, blood pressure or lipid levels.

Fasting May Still Have Benefits

While this study questions whether meal timing itself drives weight loss, proponents argue that time-restricted eating can still be an effective weight-loss tool. By limiting the hours when eating is allowed, people may naturally consume fewer calories without having to consciously track their food.

A 2020 review of 27 studies found that various intermittent fasting approaches helped people lose up to 13% of their body weight on average. Five of the studies focused specifically on participants with type 2 diabetes and found intermittent fasting improved their blood sugar control.

More Research is Needed

However, experts caution that more research is needed to fully understand the long-term sustainability and safety of time-restricted eating for weight loss. A recent study from Shanghai Jiao Tong University School of Medicine even linked intermittent fasting to potential heart health issues.

The Bottom Line

This new study adds to the debate around time-restricted eating, suggesting that while it can be an effective weight loss strategy for some, eating fewer calories overall is likely more important than the specific timing of meals. If you’re considering intermittent fasting for weight loss, talk to your doctor first to see if it’s right for you. Focus on adopting a balanced, nutritious eating pattern that you can sustain long-term.