The ‘eat-too-much, do-too-little’ theory of obesity claims that weight loss is possible through forced calorie restriction and exercise. However, neither of these things treat the cause of obesity, and for this reason both are ineffective. Obesity is a metabolic disorder characterised by insulin resistance. The underlying causes of obesity are complex, but it is becoming clear that low quality diets, typified by high intakes of refined carbohydrates including fructose, are pivotal in the aetiology. Research suggests that it is the overloading of the liver by such nutrients, that results in an inability of the hepatocytes to process the energy. This causes an increase in the production of fats, which ultimately get deposited in muscle and liver tissue, causing insulin resistance. As obesity develops, insulin resistance causes further misallocation of energy from oxidation to storage, with the result that adipose tissue becomes excessive.
Humans can store fat in both a subcutaneous compartment and an abdominal compartment. The subcutaneous fat is the visible fat below the skin, and storage of triglycerides in this location is not associated with disease. The abdominal fat, also called visceral fat, is stored around and in the organs of the abdomen, and is associated with cardiovascular disease and increased mortality. While subcutaneous fat is highly visible, abdominal fat can often be present in normal weight individuals. Being overweight itself does not increase the risk of mortality unless abdominal adiposity is present. Obese individuals attempting to lose this excess weight have a problem, in that they have become leptin resistant. Any attempt to reduce calorie intake or increase physical activity is met with reductions in resting metabolic rate and physical activity levels because the leptin signal suggests to the hypothalamus that reserves of energy are low.
In order to overcome obesity, it is necessary to remove the leptin resistance. This can be achieved by reducing insulin levels, the primary cause of the disrupted leptin to hypothalamus signal. Insulin resistance is reversed through intake of a high quality diet that contains no refined carbohydrates, particularly fructose. Reductions in the intake of fructose reduces the metabolic overload induced on the liver and decrease the production and deposition of fats in the liver and muscle. This reduces the insulin resistance and, in combination with low insulin stimulation through avoidance of refined carbohydrates, causes the oxidation of fatty acids. Because the abdominal adipose tissue is labile, the fatty acids for energy production come primarily from this compartment. This explains the improvement in metabolic parameters with increased diet quality. Only following this process is intense physical activity then effective at removing the subcutaneous fat.