New Year, new you, new juice cleanse. Right? Wrong. At the start of a new year many people look to healthier options to clean up their eating habits, but embarking on a "detox" diet of solely fruit and vegetable juices is not an ideal road to take. And we've got the science to prove it. Many dietitians, doctors, and scientists recently told TIME that they consider detox juice cleanses even less effective than fasting with water. And they also revealed what exactly happens to your body when you put it through one of these fairly detrimental diets. (Spoiler: It doesn't sound all that healthy.) They are the reasons that you should never, ever go on any kind of juice cleanse.

1. Your metabolism will slow down.

The system that converts your food into energy takes a serious breather once you stop fueling it with basic daily requirements (about 1,200 calories per day). Sure, cutting calories can lead to weight loss but cutting too many can have the opposite effect because your body goes into "conservation mode." This will have the added effect of making you feel weak, light-headed, or sluggish, and even give you headaches.

Transport, Passenger, Service, Public transport, Employment, Machine, Airline, Air travel, Aerospace engineering, White-collar worker, pinterest
GIPHY

2. You'll only drop water weight.

Don't get excited about the lost pounds; they're only temporary. When you eat a very low-calorie diet, your muscles use up their glycogen storage, which holds water. Once you return to a normal diet, you'll gain back glycogen (and the water weight) almost immediately.

Wall, Ceiling, Snout, Symmetry, Stuffed toy, Molding, Primate, Plaster, Toy, Daylighting, pinterest
giphy

3. Your skin will dry out.

With all that lost water weight comes lost moisture in your skin. A prolonged juice cleanse can also prematurely age your skin since you'll be lacking essential fatty acids.

Face, Nose, Lighting, Eye, Hairstyle, Skin, Chin, Forehead, Eyebrow, Lampshade, pinterest
giphy

4. Your hair and nails won't grow.

Your juice cleanse means you're not consuming enough nutrients and your diet isn't balanced. (Obviously.) But those missing proteins, fats, and carbohydrates means your hair, nails, and skin won't be as healthy. And that's just a damn shame.

Human body, Chest, Abdomen, Fashion, Cool, Trunk, Thigh, Costume, Undergarment, Muscle, pinterest
giphy

5. You'll be more sensitive to cold temperatures.

Most people look to hot foods like soups, stews, and even hot tea to help regulate their body temperature once the weather dips below freezing. When it's frigid outside, who wants a cold-pressed juice over a belly-warming broth?

Face, Cheek, Forehead, Helmet, Collar, White, Organ, Headgear, Personal protective equipment, Electric blue, pinterest
giphy

6. You don't "flush" any "toxins."

You want to "detox?" Well what exactly are you trying to get rid of? Most patients have no idea, says Dr. James H. Grendell, the chief of nutrition at Winthrop-University Hospital in Mineola, N.Y. And even if they did, they wouldn't need kale juice and apple cider vinegar to do it. "The human body is well designed to eliminate wastes and toxins, and a number of organs play a role," he told the New York Times. Basically, your body can do this on its own. No need to give yourself diarrhea for a week.

Follow Delish on Instagram.