Do you want to lose weight or fat? Too many times people tend to confuse the two terms, viz. "weight loss" and "fat loss". They feel that both terms mean one and the same thing and so they can be used interchangeably. However, there is a big difference between weight loss and fat loss. If you want to lose fat but not weight, your approach will be different from someone who is looking forward to losing weight.
For example, when your weigh yourself on a scale, you get your body weight, not fat weight. If you weigh yourself on a scale early in the morning before breakfast, you will get to see the lowest measurement of your body weight. This measurement won't tell you how much fat you have lost but it it will give you an idea of your total body weight, which includes fats, muscles, tissues, waste products, etc.
Now, if you are tired of being an overweight adult and want to become slimmer, what you need to lose is fat and not weight. Many obese adults want to lose only fat, but they mistake it for weight loss.
About dieting. So, what about fad diets? Well, fad diets help you lose weight but do not necessarily help you lose fat. You see, most fad diets place severe restrictions on your food intake. More often than not, these fad diets will ask you to eliminate carbohydrates totally from your diet. Some fad diets will also call for a drastic reduction in food intake. When you reduce your food intake, your body doesn't get the right amount of nutrition; moreover, since you have totally eliminated carbs from your diet, it cannot produce energy either. Then it turns to your muscles instead of fat: it eats away your muscles in order to produce the required energy. This makes you weaker, but NOT leaner, because you have not lost an iota of fat from your body; it is kept as reserve by your body for emergency. So if you expected that once you skip meals your body will automatically burn fat you will see just the opposite. Fad diets can actually burn muscle (instead of the fat deposits you wished to burn) which are the source of your strength,. This is how fad diets fail to make people slimmer.