The present invention relates to whey protein micelles for use in the treatment and/or prevention of overweight and/or obesity in a subject. The invention relates also to a non-therapeutic use of whey protein micelles to increase satiety and/or postprandial energy expenditure in a subject. A further aspect of the invention is a food composition to be administered to an overweight or obese subject, or to a subject at risk of becoming overweight or obese.