Is intermittent fasting good for weight loss — and do I need supplements during it?

Intermittent fasting (specifically time-restricted eating within an 8–10 hour window) produces modest weight loss of 1–8% over 3–6 months in trials, primarily through a spontaneous caloric reduction, the evidence does not clearly show that the timing per se produces benefits beyond what is explained by total caloric reduction, but for men who find time restriction easier to maintain than calorie counting, the behavioral adherence advantage is clinically relevant (Lowe et al., JAMA Intern Med, 2020).

Supplements during fasting windows: creatine can be taken any time (it does not break a fast metabolically in clinically meaningful ways for most protocols). Essential amino acids and protein supplements technically end a fast. Electrolytes (sodium, potassium, magnesium) in unflavored form do not meaningfully affect fasting metabolic state. The "extended fast supplement" category (exogenous ketones, "fat burner" products claiming to preserve fasting benefits) is largely Unsupported (5) for specific health outcomes beyond novelty.

Honesty Scale: Promising (2) for time-restricted eating for weight loss in compliant men.

What to do: If you fast, continue creatine and electrolytes during the fasting window, neither breaks the physiologically relevant aspects of your fast. Take protein and carbohydrate-containing supplements within your eating window.

For the full picture, read The Supplementation Deep Dive