Obesity Obesity is an excess of body weight caused by overconsumption of calories and physical inactivity. Some other causes may include: hormonal imbalances, stress, medical conditions, genetics, toxins, or a side effect of medications. 5 Foods that Cause Obesity Sugar Increases hunger and leads to the consumption of empty calories. junk foods These foods are meant to be addictive and the quantity may be hard to control. Refined flour Refined products are also addictive and may lead to overeating. Sweetened beverages Most people do not account for the calories in the beverages before consuming them. Trans and hydrogenated fats These fats promote inflammation and are only found in foods devoid of any real nutrients.