Intermittent Fasting May Boost Weight Loss — Especially with Early Eating, Study Finds

If you’re aiming to shed some pounds, adjusting when you eat might be more effective than changing what you eat.

A new analysis by researchers at Bond University in Australia found that intermittent fasting — particularly when eating is limited to earlier in the day — can lead to greater weight loss than standard nutritional advice alone.

The review, published in JAMA Network Open, evaluated 29 clinical trials involving 2,485 participants. The findings showed that restricting eating to an eight-hour window or less was linked to the most significant weight reduction, especially among individuals with higher body mass indexes (BMIs).

Intermittent fasting (or time-restricted eating) involves confining food consumption to a specific portion of the day — and though previous research has produced mixed results, it’s been associated with benefits like reduced inflammation, improved immune response, and a lower risk of type 2 diabetes and heart disease.

However, one recent large-scale study warned of potential risks: people who ate within an eight-hour window were more likely to die from heart disease compared to those who ate over 12 to 16 hours. Despite that, the new review leans in favor of earlier and shorter eating periods for weight loss.

Eat earlier, sleep better

Stephanie Schiff, a registered dietitian at Northwell Huntington Hospital (not involved in the study), says she now regularly recommends time-restricted eating after years of skepticism.

“I usually follow a 12-hour eating window, but it really depends on your personal needs,” Schiff said, adding that not eating after 6 or 7 p.m. can also improve sleep by allowing the body to digest and promote melatonin production.

If an early dinner isn’t possible, Schiff suggests having your largest meal earlier in the day and eating lighter as the day progresses.

The Bond team also noted that fewer meals throughout the day were generally linked to less weight loss, emphasizing the importance of meal timing over frequency.

Still, researchers acknowledged limitations in the quality of most of the studies analyzed, calling for longer and larger clinical trials to confirm the results.