Causes of obesityObesity is a complex issue with many causes. Obesity and overweight is caused when extra calories, particularly those from foods high in fat and sugar, are stored in the body as fat.Obesity is an increasingly common problem because the environment we live in makes it difficult for many people to eat healthily and do enough physical activity.Genetics can also be a cause of obesity for some people. Your genes can affect how your body uses food and stores fat.There are also some un