Slow changes pay off in the long run...
Everywhere you look there is a diet promising you to lose the most amount of weight in the quickest amount of time, and if you have been trying to lose weight for some time these diets can be very tempting.
When you try a fad diet, you will lose pounds in a matter of days, as promised, because you will be eating a very restricted diet but most of the weight you will lose is just water weight and this can lead to dehydration.
Muscle loss is also a major negative effect of fad diets. Since your diet is very low in calories, your body will look for other ways to get energy. One of these ways is by eating away at your muscles. This will slow down weight loss because the more muscle you have the more calories you burn, even when you are resting. Another side effect of you restricting your calorie intake is that you will feel very low on energy and fatigued throughout the day, even your normal day to day tasks can become hard work. Once you stop the fad diet and get back to your normal lifestyle, it is highly likely you will put the weight back on, plus a few extra pounds.
The only true way of losing weight and keeping it off is by making that commitment to change your lifestyle for the better, with a healthy diet and regular exercise.