Juice cleanses have been all the rage the past several years and it's no wonder why. Millions of Americans are overweight and often too busy to cook healthy meals or go to the gym. So simply downing a bottle of juice sounds like a win-win — you get all the vitamins and nutrients you need in a fraction of the prep time and calories.

According to Forbes, fresh-pressed juicing has exploded to a 3.4-billion-dollar industry. With all the buzz and popularity surrounding the industry, you might be wondering if the juice (cleanse) is worth the squeeze. Below, I examine the top two claims that juice cleanses make:

Claim #1: Juice cleanses aid in weight loss.
If all you eat or drink is three juices per day for two weeks, you likely will lose some weight. How could that possibly be a bad thing?

Losing weight should never be your goal, but losing fat should be. By depriving your body of calories and protein for two weeks, your muscles will start to atrophy and some of the weight you lose will be from muscle mass, which is the opposite of what anyone who wants a toned body should strive for. Muscle mass helps give you strength, definition, and it helps raise your metabolism.

Let's put it into perspective: If you were to lose 10 pounds on a juice cleanse and five of those lost pounds were muscle, your metabolism would be slower than it was when you were 10 pounds heavier. This is what causes your weight to yo-yo. You may be 10 pounds lighter now, but with a slower metabolism, you're more likely to gain that 10 pounds back (and then some).

You could argue that working out more during your cleanse would help you keep muscle but I doubt many fitness professionals would recommend working out while only consuming a few hundred calories a day.

Dropping this low in calories will completely deplete your body of the energy it needs, not only to get through workouts, but to get through your daily life.

Claim #2: Juice cleanses help rid the body of harmful toxins.
Your body already has an excellent way to get rid of them via the kidneys, liver, etc. If you're unable to get rid these toxins from your body naturally, then you should be immediately rushing to see your doctor, not rushing to buy a 14-day juice cleanse. This argument is based solely on fear. The problem is, the fear isn't based on any science.

The takeaway: I would be remiss if I didn't mention that some these juices can have a positive effect on your health. If your normal diet is lacking in fruits and vegetables, supplementing your diet with a juice occasionally can help boost your intake. Just make sure you're not rely solely on juices and smoothies as the answer to all your health woes.

Brian Maher is the owner of Philly Personal Training, the only personal training studio or gym in Philadelphia that requires its personal trainers to possess a college degree in an exercise-related field, as opposed to a basic certification.