In terms of treating obesity, a low calorie, low sugar diet is the most effective and recommended diet for sufferers of the disease. However, dieting itself can have a negative impact. When a person loses weight, the body ‘thinks’ it is starving and energy expenditure is reduced in order to conserve calories. The reduction in energy expenditure with dietary weight loss requires that, in order to maintain weight loss, the dieter eat even fewer calories than someone of equal body size who has never been on a diet. However, eating less is difficult following a diet because there are long-term changes in regulators of appetite that increase the desire to eat and the amount of food that can be consumed. Such diet-induced changes lead to a positive energy balance and weight regain and, because the conditions responsible for the reduction in energy expenditure and increased drive to eat persist long-term, an individual will often not only regain all of their lost weight, but even more.
In addition, diets can also have a negative impact on a subject’s metabolism. With dietary weight-loss, the amount of dietary fat the body burns is reduced by approximately 50 percent. In addition, dieting reduces the amount of fat the body burns for fuel during low-grade activity such as walking, cleaning the house, fixing dinner, or working on a computer. The reduction in the amount of fat that is burned for fuel following a dietary weight-loss makes more fat available to be stored, and dieting increases the capacity for fat depots to store even more fat than before a diet.
Therefore, while dietary changes are necessary when seeking to lose weight, it is very easy for them to fail and prove not only ineffective but cause a subject to gain even more weight than previously. It is necessary to consult with a dietician before creating a meal plan to ensure you have a diet that suits your personal needs, wants and lifestyle.