Controlling food intake and energy balance: which macronutrient should we select?

Introduction ‘Count genes, not calories’ was the title of a nutrition article in the Financial Times of Friday, 13 June 2003. It referred to the results of the Human Genome Project and the discovery of our 35 000 genes, whose functions are currently both known and unknown. It also mentioned the study that painstakingly and systematically analysed all 17 000 genes of the Caenorhabditis elegans worm to see which ones were involved in fat storage [1]. The result was 305 genes whose inactivation reduced body fat and 112 whose loss led to extra fat. As the titles of these articles indicate, it is clear that more emphasis should and will be focused on the importance of genetic background in body weight regulation. Putting on weight is the end result of a highly complex and still largely unknown system, almost every step of which can be modified according to our genes.