It sounds too good to be true. Lose weight while getting a bunch of nutrients from fruits and veggies, AND have no worries about preparing all of it (beyond throwing it in a juicer)? Unfortunately, juicing is a little too good to be true, and here's why.
1. Juicing removes many benefits of fruits and veggies
When you juice fruits and veggies, you leave out, well, pretty much everything except the juice. That means you miss out on the fiber and antioxidants that the skin and pulp offer.
2. High sugar amounts
If fruits that are naturally high in sugar are included, what results is a juice that concentrates not just the nutrients of the fruit, but the sugar, too, which is not good for you in a number of ways (including weight gain).
3. No real weight loss
If losing weight is one of your goals, then juicing is not ideal. You might lose weight after the first few days, but you drink only juice, the severe calorie restriction will only slow down metabolism. The high sugar content will also contribute to this weight gain.
4. Your body doesn't need a detox
Your liver, lungs, digestive system, and kidneys work naturally (and effectively) to clean the body of any impurities. Additionally, juicing has been linked to liver disease and damage (though this, too, is due to sugar).
In the end, juicing isn't necessarily terrible for you, but like anything else, it is unhealthy without moderation. Make sure to use more vegetables than fruits if juicing, and make sure to still eat other sources of nutrients. In the end, though, it's easier and healthier to just eat the fruits and veggies whole. It's always a good idea to be skeptical of trendy "healthy" diets and fads.