There are literally hundreds of diet plans that promise to help you lose weight. Among the most popular are fad diets. You know, those diets that sometimes have you eating strange combinations of foods on a regular basis in order to drop those unwanted pounds.

But what is the truth about fad diets?

Do they really help you lose weight, and if so, what are some of the side effects that can happen when you go on one?

Let's look at three current popular fad diets:

Grapefruit Diet â€" This diet has been around for years, and it's still going strong. Probably because when we think of grapefruit, it's easy to imagine that eating a bunch of it for a week or two will help you to lose weight. But what's the real truth?

This diet supposedly works on the theory that grapefruit is a fat-burning food, but there is no proof that this fruit has any real fat burning enzymes.

Side effects: For most people, consuming half a grapefruit with every meal isn't going to do anything bad, except maybe make you hungry between meals. However, if you are on prescription medication, you should consult your doctor before eating any grapefruit or trying this diet. Grapefruit has been proven to interfere with medication.

This is not a diet you should follow for more than a few weeks, since it doesn't have enough carbs or protein to keep you feeling satisfied. Beware that it may also cause you to crave sweets, which can lead to overeating again.

Ice Cream Diet â€" Ok, it was only a matter of time before someone came up with this brilliant idea. Ice cream is the ultimate temptation and including it as part of a diet plan is a big plus for those who have a sweet tooth.

On the positive side, ice cream does have some nutritional value. One serving of ice cream a day helps keep your bones strong, helps to boost your immune system, and reduces cravings for other sweets. All of this is great as long as you stay within your recommended calorie intake per day. For women that means no more than one cup, for men 1-1/2 cups.

Side effects: You risk not being able to control the amount of ice cream you eat. One cup turns into a pint or half a gallon and soon you've gained even more weight.

Cabbage Soup Diet â€" Another oldie that has made the rounds numerous times, the Cabbage Soup Diet is a 7-day short-term diet that is supposed to help you drop pounds quickly. There are numerous variations of this diet, but the basic diet consists of: cabbage soup (as much as you want), fruit (except bananas), vegetables, some beef and water.

Side effects: The weight you lose is mostly water weight and will be gained back quickly. The  diet causes you to have gas and bad breath. You may experience hunger pangs, headache and dizziness due to severe calorie restriction.

The only way to guarantee that you'll lose weight is to follow an easy meal plans diet that works for your particular lifestyle. That means, the diet should have calorie requirements to maintain weight loss: For women â€" at least 1500 calories per day. For men â€" at least 2000 calories per day.

Try to look at weight loss as an investment in your good health, instead of a quick fix, this is the best way to ensure you'll be successful in losing weight permanently.