If eating more greens is one of your New Year’s resolutions, make sure they are whole veggies not green juices. While many people are dusting off their juicers to prepare for the post-holiday “detox,” nutritionists warn that drinking green juices instead of other foods may lead to nutritional deficiencies, energy imbalance and more.

According to Eat This, Not That!, green juicing typically involves pulverizing fresh fruit, veggies and herbs to separate the liquid from the fibrous flesh. While this preserves many nutrients such as folate, antioxidants, and vitamin C, it removes the fiber.

Fiber plays an important role in lowering cholesterol, digestive regularity, and stabilizing blood sugar levels. When the liquid is separated from the pulp of fresh fruits and vegetables during juicing, most of the fiber is left with the pulp which is often discarded. So, the juice doesn’t have the same nutritional value as the whole fruit.

If your juice contains fruit, that can lead to a big dose of sugar, which can elevate your blood sugar levels, says Dr. Sean Hashmi, regional director of weight management and clinical nutrition for Kaiser Permanente Southern California. “You’re getting all the sugar straight,” he says. “So, juicing is often a great way to elevate your sugars.” Hashmi reiterates that removing the fiber is a poor choice for gut health, too. “All those wonderful bacteria you have are going to eat that fiber and grow and be able to do all sorts of amazing functions, including making several vitamins for you.” Juicing deprives your body of this benefit.

Green juice also contains minimal amounts of protein and fat, which makes it less satisfying. And unless you are getting these nutrients from other sources, you may experience vitamin and nutrient-related symptoms, such as loss of hair, skin and nail integrity, muscle loss, and delayed wound healing, say experts. While green juices are typically very low in calories, following a restricted diet that depends on juice for a prolonged period may lead to significant calorie depletion and adverse side effects to health and metabolism.

“Not only can a severe calorie deficit increase the likelihood of nutrient deficiencies and promote rapid loss of muscle — which can slow metabolism — it is unrealistic to maintain,” notes Erin Palinski-Wade, a registered dietitian, and the author of the best-selling “2 Day Diabetes Diet.”

Eating fresh, whole produce is an excellent way to add vitamins, minerals, and antioxidants to a well-rounded diet. But when juicing is used to replace whole foods and balanced meals on a regular basis, it may do more harm than good, says Eat This, Not That!

If you want to try juicing, replace no more than one meal a day with your green drink and make sure your other meals contain protein, fat and fiber not found in the juice.