To fast or not to fast, that is the question

Oldenburg N, Mashek DG, Harnack L, et al. Time-restricted eating, caloric reduction, and unrestricted eating effects on weight and metabolism: a randomized trial. Obesity (Silver Spring). 2025; 1-14. doi:10.1002/oby.24252

What was the study about?

• A 12-week clinical trial compared time-restricted eating (TRE), caloric restriction (CR), and unrestricted eating (UE) to see which was more effective for weight loss and metabolism.

Who was studied?

• Adults following either: TRE (8-hour eating window), CR (15% fewer calories daily), UE (normal diet, no restrictions - control group)

What did they find?

• TRE alone was not superior to caloric restriction.

• CR led to slightly more weight loss (-2.5kg vs. -1.4kg for TRE).

• No major metabolic improvements in glucose, insulin, or fat metabolism.

Why does it matter?

• While TRE may help control calorie intake, it might not be better than simple calorie reduction for weight loss.

• More research is needed to fine-tune fasting approaches for metabolic health.