The present invention relates to a method for the prevention and/or treatment of overweight in mammals. More particularly the invention is concerned with such a method comprising the enteral administration to a mammal of a preparation comprising an effective amount of a combination of dill or an isolate thereof and one or more components capable of stimulating in vivo lipolysis. Suitable examples of components capable of stimulating in vivo lipolysis include methylxanthines, adrenergic amines, Paullinia cupana or an isolate thereof, Zingziber officinale or an isolate thereof, Camellia sinensis or an isolate thereof, Ilex paraguayiensis or an isolate thereof.Another aspect of the invention relates to a solid or semi-solid unit dosage, preferably selected from the group consisting of tablets, pills, microparticles, microspheres, suppositories, capsules, caplets and the like, that is suitable for enteral unitary administration to human subjects and other mammals comprising: a. dill or an isolate thereof in an amount equivalent to between 5 mg and 20 g dill and b. a component capable of stimulating in vivo lipolysis.