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Consume nothing but juices for a few days and — presto! — you’re healthier. That’s the promise many juice companies are selling, and plenty are paying big bucks to jump on the trend. But do the bottled promises really live up to the hype, or do drastic detoxes deplete the brain and mess with your metabolism and muscle tone, making it hard to operate (in life or in the gym) at optimum levels? Turns out the high price tag isn’t the only cost of a purge.
Promise: You’ll improve your mental clarity and fine-tune your focus.
Reality: Mental fog will set in with a dash of irritability. “There is nothing metabolically going on when someone does a juice fast that will increase their mental clarity,” says Melinda Johnson, clinical assistant professor and director, Didactic Program in Dietetics, Arizona State University. Your brain needs protein and fat to function optimally; without them, your concentration and mood can suffer. “Depending on the juice fast, a person may go into a state of ketosis, which can give a person ‘brain fog’ and impact mood,” Johnson adds. What’s more, drastic diets can cause obsessive food thoughts (I need chocolate NOW!) and make it almost impossible to achieve high levels of performance in the gym.
Promise: You’ll drop pounds.
Reality: Limiting your body’s calories can set you up for weight gain. Yes, you’ll shed water weight, and because most cleanses supply only half the calories you need, you may drop a pound or two — at first. But without adequate protein, your body begins to lose hard-earned muscle mass, which can affect your metabolism. “Any weight loss produced during a liquid cleanse will almost assuredly be followed by weight gain,” says Michelle Babb, MS, RD, a nutritionist in Seattle.
Promise: You’ll rid your body of toxins.
Reality: Your body doesn’t need a deprivation diet to detox. Juice companies proclaim that taking solid food out of the equation gives our bodies a chance to eliminate built-up toxins. However, it isn’t scientifically proven that your body actually needs to be cleansed or that anything extra is “freed” on a juice cleanse. “A healthy diet of whole fruits, veggies, whole grains, lean protein, low-fat dairy, healthy fats and minimal consumption of highly manufactured foods is the most wonderfully detoxifying way to eat,” says Jennifer Neily, MS, RDN, a registered dietitian in Dallas.
Promise: Juice cleansing is like mainlining nutrients.
Reality: With the nutrients comes heaps of sugar.Juices deliver a potent dose of antioxidants that help support the immune system, but it’s a temporary fix and may not be good for people with blood-sugar management issues, Babb says. That’s because juice cleanses are higher in sugar than you may think: One popular juice-cleanse program contains a whopping 180 grams of sugar in one day — that’s seven times more than the Recommended Daily Intake. Over the long haul, too much sugar may harm the brain and impair memory. You need a more balanced approach to macronutrients to fuel your workouts.
Promise: Energy levels will skyrocket.
Reality: Limiting calories can limit energy. “Depending on how long the juice cleanse lasts, our body can go into starvation mode, where it attempts to conserve energy by slowing things down — making us feel less energetic,” Johnson says. Not getting adequate fat and protein can zap energy even more, not to mention the sugar crash: “Juice can cause a rapid increase in blood sugar, followed by a sharp decline, which leaves you feeling tired and hungry,” Babb says. Remember, as an active woman, you need food to fuel your busy life and challenging workouts. Your best bet is to make healthy nutrition choices and don’t be too quick to jump on the deprivation bandwagon.