To Juice or Not to Juice

The juice cleanse has become increasing popular as consumers strive to lose weight and detoxify their body from chemicals and processed foods.  During a juice cleanse, a person is limited to solely fresh fruit and vegetable juices and water for a period of time ranging from days to weeks.  The juices are usually freshly made and unpasteurized, and they offer an average 1000-1200 kcal per day.  While many of these juices are nutritious, a liquid juice diet may be more harmful than beneficial.

Whole fruits and vegetables are more nutritious than juices since whole foods have more fiber and antioxidants in their skin and seeds; the amount of fiber and antioxidants is decreased during the juicing process.  Because there is less fiber in the juice, the body absorbs the carbohydrates at a much faster rate, which raises blood sugar levels quickly.  Additionally, satiety is decreased when you drink beverages rather than chew food, and this fact combined with the decreased fiber in juice can leave you feeling less satisfied and less fulfilled.

A diet filled with only juices is missing many critical nutrients that your body needs to function properly, including adequate protein and fat.  Protein is the building block for tissues and muscles. It is also needed for metabolism and proper hormone and immune function. Without adequate protein, your body will break down muscle as more vital cellular processes (e.g. respiration enzymes, blood cells) recycle muscle protein for their own requirements.  Fat is necessary in the body as a source of energy and for the structural components of cell membranes. Adequate fat is necessary to regulate body temperature and help protect the heart, kidneys and liver. Additionally, fat is needed for the absorption of fat soluble vitamins which play a role in brain development, blood clotting and managing inflammation.

It is important to recognize that a juice fast can be especially dangerous for some people. Anyone with cancer, diabetes, kidney disease, or nutritional deficiencies should avoid juice cleanses. The high antioxidant level and low protein level can be dangerous for those undergoing chemotherapy, the high sugar content can increase blood sugar levels in diabetics, and the high levels of potassium and other minerals can be dangerous for those with kidney disease.  Additionally, pregnant women and those with autoimmune diseases should avoid juices cleanses because they are unpasteurized.

Despite the aforementioned issues, many people report feeling great and having more energy while on a juice cleanse. This is most likely because the daily diet of the general population consists of many processed foods and chemicals, few fruits and vegetables, and not enough water.  One of the benefits of a juice cleanse is the number of fruits and vegetables consumed in a day; you would definitely meet the recommended servings of fruits and vegetables. It can also help someone break the cycle of unhealthy eating habits.

Overall, juice fasts are a type of fad diet and not an effective way to lose weight. Most people will lose weight on a juice cleanse, but it is water weight and not fat mass, so the majority of people will regain the weight as soon as they restart a regular diet. Additionally, consistent juice fasting can permanently lower your metabolism since the body is not getting adequate nutrients and thinks it is starving.  If you still want to try a juice cleanse, modify it by adding a protein source and do it for only a few days.  Another option would be to replace one meal with a juice while again, making sure to have adequate protein. Remember that there are no quick fixes and the most effective way to lose weight is still through moderation and a healthy balanced diet.