A cleanse may also keep some people’s energy levels more consistent, Ms. Czerwony said, because of what they are eliminating from their diets, as opposed to what they’re adding. When people opt for a cleanse, they tend to drink more water and consume less added sugar than they normally do, she said. If they typically eat heavy, processed foods and then swap those out for fruit- and vegetable-based smoothies, they might reap the benefits of cutting back on added sugars and fat. Foods loaded with refined carbs, like white bread and pastries, can make our blood sugar spike, and then our energy levels may crash as our glucose levels slide back down.
But while some people may feel more energetic on a cleanse, others might be exhausted and struggle to get through the day because of how few calories they are consuming, Ms. Czerwony said. Some people experience headaches and become irritable; they can also develop diarrhea or constipation.
There’s no science-backed, individual component of a cleanse that makes you healthier, Ms. Czerwony said. A 2014 review of past studies on detoxes found that the research was largely flawed; a separate 2017 review found that juicing and detoxification diets led to weight loss over short periods of time because of how few calories the participants consumed while on them, but they tended to experience weight gain once they resumed eating normally.
If you are going to try a cleanse, you should choose one that lasts no longer than three days, Ms. Czerwony said. The limited time frame is important so you avoid nutrient deficiencies and imbalances in your electrolyte levels. It’s also critical to make sure you’re not consuming dangerous levels of vegetables and fruits, which may seem counterintuitive. A few case reports have found that people on juice cleanses can develop kidney issues, because certain vegetables like spinach are high in oxalate, and high oxalate levels can cause kidney stones, Dr. Mullin said.
“They don’t just do one smoothie — they live on it,” he said. “Some people overdo it.”
And any supposed benefits from a temporary juice cleanse won’t counteract the toll of an unhealthy diet, Dr. Ring said. To incorporate healthier habits for the long term, eliminate processed, packaged foods as much as possible, and make sure you’re getting the recommended five servings of fruits and vegetables per day, Ms. Czerwony said. Opt for complex starches like whole grains instead of processed flour, and stick to foods that are high in fiber, like nuts, beans and apples, which can help regulate your G.I. tract. A moderate level of exercise and good sleep can also give you more energy throughout the day. But you don’t need to turn to a detox to feel better. As Dr. Mullin said, “the body knows how to take care of itself.”
