In the diet industry, anything goes. Many of them are short-term fixes and they do not work for the majority of the overweight people. If they did, there would not be so many of them still around.
There are no short cuts and no magic pills. Losing weight sensibly and safely requires a multifaceted approach. That includes setting reasonable goals, changing eating habits and exercise. Diet pills and fad diets may help some people over the short-term, but they are not a substitute for adopting healthy lifestyle changes over the long-term.
Fad Diets
A fad diet is one that makes unrealistic promises. Most fad diets are very low in carbohydrates and in calories, causing fluid loss from the body, which indicates a loss of weight on the scale. One gram of carbohydrate binds 4 grams of water. So if you lose 400 grams of carbohydrates, you lose 1600 grams of water & you will weight 2 kg less on the weighing scale. But once the body gets rehydrated with water, the weight will come right back.
Low Carbohydrate Diets
There is hardly a shred of scientific evidence that low carbohydrate diets benefit anyone. Low carbohydrate diets come in many forms. The Zone diet (less extreme form) recommends less carbohydrate (40% instead of 55%), more protein (30% instead of 15%), and limits fat to no more than 30%. It includes advice about types of carbohydrate (low versus high GI), and types of fat (unsaturated versus saturated). In order to keep to these limits, specially nature is such that after a while you will find yourself yearning for high-carbohydrate foods like bread & potatoes.
A more extreme form is the Atkins diet, which is being used to induce short-term weight loss. This diet is based on the concept of avoiding carbohydrate foods - even fruits & vegetables are restricted (absurd!)- while meat 7 dairy foods laden with saturated fat, cholesterol and calories form the core. A recipe for sudden heart attack! It may also compromise kidney function if prolonged.
Low Calorie Diet
Low calorie diet (LCD) provides a calorie deficit of 500 to 1000 kcal/day from maintenance requirement. LCDs reduce total body weight (average of 8-10% over 6 months) and waist circumference. Weight loss is usually about 75% fat (mainly abdominal fat) and 25% lean tissue. You can expect an average weight loss up to 11 kg as well as a reduction in waist circumference of 1.5 to 9.5 cm after 6 to 12 months.
In general, a LCD diet containing 1,000 to 1,200 kcal/day should be selected for most women; a diet between 1,200 kcal/day and 1,500 kcal/day should given to men and also for women who weigh 75 kg or more or who exercise regularly. if the person is unable to lose weight on 1,500 kcal/day diet, a 1200kcal/day diet may be tried. If the person remains hungry on either diet, then the calorie intake can be increased by 100 to 200 kcal/day.
