Being seriously overweight is not caused by one single factor. There are a number of things that contribute to one becoming morbidly obese. These include:
Family history — Genes do play a part in how your body balances calories and energy. Children whose parents are obese also tend to be overweight. You can not change your genetic makeup by willpower any more than you can make yourself taller or shorter by wishing. But, you can still achieve your weight loss goals even with a family history of obesity.
Culture — People learn to eat and cook the way in which they were brought up. Food choices and combinations are learned very early in life, and social events and family rituals often are centered around meals.
Physical inactivity — Overweight people are usually less physically active than normal weight adults. Seriously overweight people may have difficulty moving. To add to this, we depend on many labor-saving devices which makes for less physical activity.
Emotional or psychological factors — For many, food is often a source of comfort or celebration. Some eat when they are feeling sad; most of us eat to celebrate events and occasions. Food may become less important to you after weight loss, especially surgery. Weight loss will allow you to acquire new interests and become more active and focused on other things besides food.
Gender — Women are more likely to be obese than men simply because men have more muscle than women. Muscle uses more energy than fat does, and men burn 10 to 20 percent more calories than women do at rest.
Age — As you get older, the amount of muscle in your body tends to decrease, and fat accounts for a greater percentage of your weight. This lower muscle mass leads to a decrease in metabolism.
High-fat/High-calorie diets — Ounce for ounce, fat provides more than twice as many calories as protein or carbohydrates. This energy difference may explain how fat promotes weight gain.
A good way to recognize obesity is by using a BMI calculation. This tool measures your height/weight ratio. It is your weight in kilograms divided by the square of your height in meters. BMI calculator
Another indicator of risk for obesity is if the waist circumference for males is greater than 40 inches and more than 35 inches for women.