The present invention concerns a composition prepared from a combination of non .beta.-oxidizable fatty acid entities and a protein material, and the use of said composition for the preparation of a pharmaceutical or nutritional composition for the prevention and/or treatment of insulin resistance, obesity, diabetes, fatty liver, hypercholesterolemia, dyslipidemia, atherosclerosis, coronary heart disease, thrombosis, stenosis, secondary stenosis, myocardial infarction, stroke, elevated blood pressure, endothelial dysfunction, procoagulant state, polycystic ovary syndrome, the metabolic syndrome, cancer, inflammatory disorders and proliferate skin disorders. An alternative embodiment of the invention includes oil in the composition The present invention also concerns an animal feed prepared from a combination of a protein material and a compound comprising non .beta.-oxidizable fatty acid analogues, the use of said feed for improving the body composition of an animal, and a product produced from said animal.