The amount of subcutaneous fat has been found to have a significant association with HDL cholesterol in serum. It has been proposed that chronic hyperinsulinemia is largely responsible for hunger, cravings and weight gain observed in many obese. This has been attributed to the frequent failures of diet and behavioral modification programs. Epidemiological evidence and animal experimentation support the role of chronic hyperinsulinemia as a major factor in obesity. This cycle maintains excess fat and can override attempts of dietary and behavioral intervention.
Body fat is reduced when a chronic negative caloric balance exists.
Both an increase in caloric expenditure through exercise and a decrease in caloric intake is usually recommended to accomplish this goal. Sheer weight loss may be challenging to predict since weight loss can vary dependent upon the method of caloric imbalance. For example, fasting and extreme caloric restriction diets can markedly decrease lean body weight and body hydration. In contrast, exercise can induce a negative caloric balance which decreases fat or increases muscle mass in varying magnitudes and proportion.