What's the difference between different types of diets?Although diets like Atkin's, South Beach, Weight Watchers, Cabbage Soup, etc. vary in some ways, the one factor they all have in common is that the primary goal for all of these diets is to get people to lower their total food/calorie intake. Whether a diet program has you count carbs, points, food exchanges, or actually count your calories, the goal is the same...lower the amount of food or the number of calories you're taking in on a daily basis.

Why do people lose weight faster on some diets compared to others?

The primary reason people lose weight faster on some diets is because of a lower calorie intake. The less food you eat, the more weight you lose (in the beginning). The problem with this is that if you cut too much food out, then your body adapts to surviving on less, and your metabolism slows down. This is what causes a plateau in weight loss and also can cause weight re-gain to levels even higher than where you started. So, faster weight loss is not necessarily better (although the idea is very attractive to many people, hence the popularity of many of these diets).

What's the difference between a low-fat compared to a low-carb diet?

A low-fat diet helps people to reduce their calorie intakes by reducing the number of calories taken in from fats (each gram of fat has 9 calories compared to only 4 calories in carbohydrates and in protein). So, cutting fat can potentially cut out a lot of calories. This is good to a point because excess fat in the diet leads to heart disease, but we do need to have some fat in our diets to be healthy. Also, fat helps us to feel full, so a diet too low in fat will leave someone feeling hungry all the time. A low-carb diet helps to reduce calories taken in because normally half of the foods we eat come from carbohydrate sources, so if we cut out half of the food we normally eat, we're obviously going to lose weight. One of the attractions to this type of diet is the ability to eat foods high in fat, which is what Americans tend to enjoy. Also, the higher fat foods help dieter's to feel more full on less, so people don't tend to be as hungry on the "low-carb" diets. The down side is that too much fat in the diet will ultimately lead to higher cholesterol and potentially heart disease or stroke.