If you’re like many people, you started a new diet on January 1st. To avoid quitting before you reach your goals, a little information about yoyo dieting might help you to stay on track, since 95% of the people who go on diets regain the weight lost, plus more, within two years of dieting.
Strive for slow and steady weight loss. A reasonable goal would be to lose one to two pounds per week. If you try to lose weight quickly by using extreme calorie restriction, you may harm your body. Restriction of calories causes muscle wasting. Your heart is a muscle, which may be affected and can lead to heart damage. All of the shrinking and expanding of the arteries and veins that happens during yoyo dieting can cause tiny tears in the walls of the vasculature, which set the stage for fat deposits in the arteries. Calorie restriction can also cause low energy due to a slow metabolism, and nutritional deficiencies, which may manifest as headaches, muscle cramps, constipation, insomnia and loss of bone density.
Calorie restriction increases cortisol levels in the body. Cortisol is a stress hormone that causes physiological changes as the body becomes stressed. When you return to your normal eating patterns after dieting, you will have a body that not only lacks muscle tone, but it carries extra fat that gets stored as a response to the stress of not having enough to eat. Lose weight gradually by eating a balanced diet and exercising moderately, which keeps your metabolism up, causing the body to burn calories, even at rest.
--Dr. Kate Kennedy