While many claim that overeating is the cause of weight gain, evidence actually suggests that it is poor blood sugar control that contributes significantly to the slow and insidious accumulation of body fat in cases of obesity. Physiologically, rapid elevations in blood sugar can produce nutrient overload in cells, and this may increase insulin resistance through the generation of oxidative stress. The development of insulin resistance is detrimental because aberrations to the insulin system cause a multitude of downstream physiological changes that then compromise metabolic regulation and make weight gain more likely. In particular, insulin resistance decouples the normal satiety response from energy intake and energy stores and also inhibits the correct oxidation of fuel. Regaining control of the insulin system through correct glycaemic control is therefore paramount in fat loss. The success of this approach is reflected in studies showing the effectiveness of high protein low glycaemic index diets in weight control.
Using a low energy diet to cause weight loss is particularly problematic, because often the energy restriction does not correct the metabolic changes that lead to the weight gain. Although weight is lost, much of this weight is muscle, and this detrimentally affects the resting metabolic rate. When normal energy intake resumes, often the same poor quality foods are consumed because the dieter has done nothing to improve the quality of the diet, but instead just simply restricted poor quality foods. Weight regain is therefore a problem as the same insulin resistant state exists following weight loss, or can quickly develop in the period of normal energy consumption. To reduce the risk of weight regain, higher quality diets should be consumed, and these diets should emphasis a high protein intake and contain carbohydrate sources of low glycaemic index. Studies show this significantly reduced the risk of weight regain, as long as high quality foods are maintained in the diet.
For example in one study researchers1, caused weight loss in subject through energy restriction. This energy restrictive diet put the subjects at high risk of weight regain. The subjects were then given one of a number of diets. One group ate a control diet which was free from restriction. The other subjects consumed either a high protein low glycaemic index diet, a high protein high glycaemic index diet, a low protein high glycaemic index diet or a low protein low glycaemic index diet. The low protein diets contained 13 % of energy from protein, whereas high protein contained 25 % of energy as protein. The results of the study showed that after 26 weeks of their respective maintenance diets, only the high protein low glycaemic index diet group remained below the weight they achieved following the weight loss phase. All other groups regained significant amounts of the lost weight. The high protein low glycaemic index group also retained the most participants suggesting that it was the easiest diet to follow.
RdB
