1. Insulin Resistance

The obesity always accompanied by Insulin Resistance, resulting in hyperinsulinemia, in direct proportion to the amount of excess body fat.

Insulin allows the body to utilize glucose (sugar) and carbohydrates. If insulin is not rapidly cleared from the bloodstream after a meal, it will cause the feeling of being hungry. Usually insulin will signal the body to stop eating, but if a person has chronically elevated glucose levels due to inefficient insulin, he may eat more. Thus, the more refined carbohydrates a person eat, the hungrier he or she may become. If you already have Insulin resistance, be careful with dieting - it might raise your problems.

To make matter worse, since the insulin is not converting the glucose to energy, more glucose is then moved into the fat cells to create more fat. When an overweight person becomes more obese, the insulin problem becomes worse as well, because the individual becomes more unresponsive to the action of insulin.

2. Leptin Resistance

Being overweight produces leptin resistance. Leptin is a hormone associated with the obesity gene. Leptin acts on the brain's hypothalamus to regulate the extent of body fat, the ability to burn fat for energy. Also leptin signals the brain satiety center that sufficient amount of food has been taken. When you're overweight, your leptin levels increase, but its action is stiftled. In obesity, leptin levels increase in concert with insulin levels.

3. Cortisol resistence

Being overweight promotes cortisol reistence. As a general rule, when you are overweight, you will have chronically higher levels of cortisol (stress hormone) production. High leves of cortisol in itself promote weight gain. The primary action of cortisol is increasing blood suger levels at the expense of muscle tissue. While this is the desired effect in a fight-or-flight situation, on a chronic nasis it will lead to insulin resistense and an alteration in body composition from muscle to fat. Furthermore, researchers believe that hight cortesol tends to increase appetite, due to an association with leptin.

4. Decrease of growth hormone (GH)

Being overweight decreases growth hormone. The resistance to insulin elevate the insulin-like growth factor 1 (IGF-1), which inhibits the production of growth hormone. Since growth hormone promotes lean body mass, enhances the peripheral conversion of thyroid hormone to metabolically active thyroid hormone, and enhances processes aimed at fat burning, the reduction in this hormone has a negative effect on the body composition.

5. Diabetes

Over time, as pancreatic beta cells continue to produce larger and larger amounts of insulin and remain unable to normalize blood sugar, they will eventually become exhausted. The progression to full-fledged Diabetes can occur over time.