The equilibrium between calorie intake and energy use determines a person's weight, the bottom line is that obesity occurs when you take in more calories than you burn through exercise and normal daily activities. Your body stores these excess calories as fat. Therefore the most common causes of obesity are overeating and physical inactivity. At present, we know that there are many factors that contribute to obesity, some of which have a genetic component:
§ Genetics: Genetics plays a crucial role in a person’s life. You are likely to develop obesity if one or both parents are obese. Your genes may affect the amount of body fat you store and where that fat is distributed.
§ Overeating: Overeating leads to weight gain, especially if the diet is high in fat. Foods high in fat or sugar for instance, fast food, fried food, and sweets have high energy density foods that have a lot of calories in a small amount of food. Studies have shown that diets high in fat contribute to weight gain. Unhealthy eating habit, having a diet that’s high in calories, junk food, skipping breakfast, eating most of your calories at night, consuming high-calorie drinks and eating oversized portions all contribute to weight gain.
§ A diet high in simple carbohydrates. The role of carbohydrates in weight gain is not clear. Carbohydrates increase blood glucose levels, which in turn stimulate insulin release by the pancreas, and insulin promotes the growth of fat tissue and can cause weight gain.
§ Prevalence eating. The relationship between prevalence of eating (how often you eat) and weight is somewhat controversial. There are many reports of overweight people eating less often than people with normal weight. Scientists have observed that people who eat small meals four or five times daily, have lower cholesterol levels and lower and/or more stable blood sugar levels than people who eat less frequently (two or three large meals daily). One possible explanation is that small frequent meals produce stable insulin levels, whereas large meals cause large spikes of insulin after meals.
§ Slow metabolism. Women have less muscle than men. Muscle burns (metabolizes) more calories than other tissue. As a result, women have a slower metabolism than men, and hence, have a tendency to put on more weight than men, and weight loss is more difficult for women. As we age, we tend to lose muscle and our metabolism slows; therefore, we tend to gain weight as we get older particularly if we do not reduce our daily caloric intake.
§ Physical inactivity: If you live sedentary lifestyle, if you spend most of your day sitting, watching television or at a desk or in the vehicle-in other words not moving, seldom walk more than 100 meters, a job that keeps you inactive, if you do not do 30 minutes to 45 minutes of exercise at least twice a week it means you are living a sedentary lifestyle.
§ Medical problems: Obesity can sometimes be traced to a medical cause, such as Cushing’s syndrome, polycystic ovary syndrome, and other diseases and conditions. Some medical Problems, such as arthritis, can lead to decreased activity, which may result in weight gain.
§ Emotional factors: For some people, emotions influence eating habits. Many people eat excessively in response to emotions such as boredom, sadness, or anger, stress. While most overweight people have no more psychological disturbances than normal weight people, about 25% percent of the people who seek treatment for serious weight problems have difficulties with binge eating.
§ Medications: Medications associated with weight gain include certain antidepressants fertility drugs, antidepressants.
§ Pregnancy: During pregnancy a woman’s weight necessarily increases. Some women find it difficult to shed weight after the baby is born.
Insomnia: Inability to get eight hours of sleep at night can cause changes in hormones that increase your appetite