Obesity is caused by overeating and not doing enough activity. It makes more vulnerable to diseases such as diabetes, hypertension and arthritis. First, some people always like to eat fast foods and buffets, which these foods usually have starches and fats. Especially, sugary foods can make some people fat and unhealthy such as sugary drinks, beer drinks and desserts. Second, lack of exercise is a risk factor for diseases. If you eat too much and don’t get exercise, your body will be fat.