1. Reason 1: By far, the most prevalent reason that people remain overweight because they eat foods that raise insulin levels. When insulin levels rise, the body converts excess sugar into fat storage, causing excessive amounts of body fat and high cholesterol.

   Foods that cause this "insulin-triggered quick fat storage" are called "high glycemic index" foods. Some examples of high-glycemic-index foods are: high fructose corn syrup, refined sugar, white rice, white potatoes, white breads, crackers, and other foods containing refined ("enriched") white flour.

   Twice the amount of food can be eaten, with no weight gain, if the food consumed is low on the glycemic index (55 or lower).

   This glycemic index list (after clicking, page-down to view) shows the glycemic index value of most common foods. Eating foods that have a 55 or lower glycemic index value will prevent the body from being able to store fat easily and thus result in weight loss.

   Overweight people often mistakenly believe that their weight is due to large bones. This is an easily-disproved myth. The entire skeletal system of an adult female weighs an average of 2.8KG (6.2 pounds) and 4.0kg (8.8 pounds) for men. Even if a woman's bones were twice the size of the average woman (this never happens), this would only account for an extra 6 pounds.
    

2. Reason 2: Eating when no physical hunger is present. Learn to listen to your body. Only eat when you are truly hungry. Ingesting calories when the body is not really hungry adds excess weight to your body. Learn to use hunger, not your eyes or nose, as your signal to eat. Whenever your body feels hungry, it is burning stored fat. Learn to enjoy that feeling of fat melting away. Allow yourself to feel hungry for at least 30 to 60 minutes before you eat. The more often you allow yourself that hungry feeling, the more stored fat you will burn. 
    
3. Reason 3: Eating past the point of satisfaction. Once again, learn to listen to your body, and know when you have had enough to eat so that you will stop when satisfied. Eating past the point of fullness increases that spare tire around your waist.

How to eat more food without gaining weight: Avoid processed and refined foods. Some people are simply "volume eaters" who enjoy eating frequently or eating large portions. Avoiding "calorie-dense" foods allows us to enjoy eating frequently or eating larger portions without gaining weight. Calorie-dense foods to avoid are: meats, butter, processed oils (cooking oil, vegetable oil, olive, etc.), and other fats such as margerine or other processed or refined fat or oil. Fried foods are very calorie dense because they contain lots of oil which remains in the foods after frying, even when it is not very visible. Frying causes oil to penetrate food, adding huge amounts of calories. Foods that are NOT calorie dense are: vegetables, fruits, grains (oatmeal, whole wheat, brown rice, corn, barley, and other unprocessed, unrefined grains), and legumes, which are beans such as pinto, garbanzo (chick pea), kidney, black, navy, etc.; also seeds (sunflower, sesame, etc). Other foods that contain higher amounts of healthy fat, which should be eaten in limited portions are nuts (peanuts, peanut butter, almonds, cashews, etc.). Avoid any foods that have a glycemic index value or higher (click on list above).

Daily Calorie Requirement Calculator determines your daily calorie requirement. Staying under this calculated number will cause you to lose weight. Keep in mind that if you eat only foods that have a glycemic index value of 55 or lower, you will lose weight faster. 3,500 calories = one pound.