Q I’ve heard a lot recently about syndrome X, but I don’t really understand what it is. Can you please explain what the symptoms are, who is likely to develop it and how it can be treated? - AJ, Plymouth
Fats, or lipids, are the third main class of the macronutrients needed in human nutrition. The lipids are found primarily in meats and dairy foods, at least, these are the most visible sources, but most foods contain some fat.