By drinking water and eating whole foods, you can burn 100–150 extra calories a day without doing anything else.
Evidence from Studies
Supporting (1)
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Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure
This study found that eating a sandwich made with real bread and cheese burns more calories after eating than one made with processed ingredients — by about 64 calories. It doesn't test drinking water while fasting, but it does prove that whole foods boost calorie burning more than processed ones.
Contradicting (1)
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Hydration biomarkers and copeptin: relationship with ad libitum energy intake, energy expenditure, and metabolic fuel selection
This study only looked at how drinking water affects calorie burning, not whether eating whole foods vs. processed foods makes a difference — so it can't answer the claim.