The weight loss industry generates a lot of revenue each year, estimated at around 50 billion dollars.  Most diets are aimed at reducing calorie intake. Short periods of calorie restriction are sometimes encouraging to the person dieting because with them comes initial weight loss, but it is often the wrong kind of weight. Most of the weight lost in the first few weeks of a calorie restrictive diet is water and carbohydrate lost from muscle tissue, and not a reduction in fat.There are some disadvantages to calorie restrictive diets including; loss of lean body mass, possible malnutrition, metabolic disorder, and fatigue. Other diets that don’t work are high fat diets, and high protein diets. The only way to safely lose body fat, is to combine a healthy diet without excess calories, fats or sugar and regular exercise.  One of the most asked questions “How many calories do i need?”. There is no easy answer. Calorie requirement is dependant not only on your height and weight, but on your lean body mass, daily activity level, and metabolism. A guideline you can follow is: For weight loss; current body weight in lbs x 10= number of calories you can consume daily, For weight maintenance; Current body weight in lbs x 12= number of calories you can consume.It is  important to remember that healthy weight loss will happen gradually, at a rate of no more than 2 pounds per week. People who want to lose weight need to remember that it is a lifestyle change, and a lifetime commitment.