Time-restricted eating vs calorie restriction — which is better for longevity?

These aren't really competing mechanisms — TRE's own best trials suggest it works largely by causing incidental calorie restriction, not through a separate metabolic pathway. A large NEJM trial and a JAMA trial both found calorie restriction with or without a restricted eating window produced similar weight loss, meaning TRE's benefit mostly comes down to eating less overall, not when you eat. Calorie restriction itself has the deeper evidence base for actual longevity (not just weight loss) — it's one of the most robust life-extension interventions in animal models, though direct human lifespan data doesn't exist and can't ethically be tested via RCT. Practically: if TRE helps you naturally eat less without a lot of effort, it's a reasonable tool for that — just don't expect it to add a longevity benefit beyond the calorie deficit itself.