The claimEvidence B · meta-analysis
Even drinking water makes you fat
The evidence
Water has zero calories and cannot become fat. A 1-2 kg daily swing is water: glycogen binds 3-4× its weight (Olsson & Saltin 1970) + sodium retention + hormones. Watch the 2-week trend.
The mechanism, in brief
A phenomenon that troubles many people: you didn't overeat, yet you wake up 1-2 kg heavier; or 'I feel like even drinking water makes me fat.' This is almost certainly water weight, not fat. Let's do the math first.
Sources (2)
- Olsson, K. E., & Saltin, B. (1970). Variation in total body water with muscle glycogen changes in man. Acta Physiologica Scandinavica, 80(1), 11-18. About 3-4 g of water is stored with each gram of muscle glycogen; a carbohydrate-rich diet raised total body water by ~2.2 L, attributed to glycogen storage.
- National Academies of Sciences, Engineering, and Medicine. (2019). Dietary Reference Intakes for Sodium and Potassium. National Academies Press.