Dietary lipids: less fat or best fat?

Obesity and overweight occurrence is growing around the word. This is often considered as a consequence of high fat diets, and some recommendations encourage "light" diets, including low fat intake. However, most trials with low fat intake do not demonstrate any benefit and could be worse than low carbohydrate diets. The key role of insulin could explain that eating fat do not make body fat. On the other hand, several unbalanced fatty acid intake are reported, i.e. saturated/mononunsaturated fatty acids and w6/w3 polyunsaturated fatty acids. Thus, fat intake could be improved in this respect. Moreover, the molecular and supramolecular structures of fat in food are new challenges to address in order to ameliorate the recommendations for healthy diets.