Key facts about fats Fats are perceived negatively by most people. They are usually seen as ingredients which contribute to weight gain. But are all fats really unhealthy? Which of them are worth eating and which should be avoided as much as possible? What are the functions of fats in our bodies? What are the characteristics of products with good fats in their composition? Is it really worth buying them? Are all fats harmful? Some people will probably say yes.