Disclosed is the use of a composition comprising docosahexaenoic acid (DHA) and/or arachidoic acid (ARA) in human subjects that are on the typical Western-type" high-fat high-sugar diet. It was found, in a humanized animal model, that said composition is capable of compensating for one or more of the adverse health effects of said diet. Particularly, an effect was found in body weight reduction, without a lowering of food intake. The composition can be administered as an oral (pharmaceutical) dosage unit, as a nutritional supplement, or as a component in a food or drink.