You may be wondering what causes this stubborn fat to form. There are several reasons. One is that you may be aging. With advancing years, the metabolism slows down quite a bit. Low thyroid hormones is another factor with excess fat, as the thyroid gland is responsible for regulating our metabolism. Other symptoms of a poorly functioning thyroid include fatigue, dry skin, emotional problems and erratic hunger cycles, and in this case you may need a prescription for thyroid medication.Yet another reason for stubborn fat is stress. Stress can result from job concerns, relationship woes, financial pressure, family drama, or just even the difficulty of navigating life in a huge city like Los Angeles. Stress cannot be underestimated in its ability to cause us to gain weight. Stress triggers the adrenal gland to overproduce cortisol, the flight or fight hormone. This in turn makes you more likely to overeat.Lastly, sleep problems can largely contribute to problems maintaining one’s figure. Leptin is a protein that works to regulate the appetite, but it gets depleted and must be restored during the sleep cycle. Thus when we are sleep deprived, our bodies get out of whack and start to rack up the pounds.