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What does a juice cleanse do to your body?

Juice cleanses have become increasingly popular in recent years as a way to detoxify the body and promote weight loss. A juice cleanse typically involves replacing solid foods with fruit and vegetable juices for a period of 3-10 days. Proponents claim that juicing floods the body with nutrients and gives digestion a rest, allowing the body to heal and restore itself. But what does the science say? Here’s an in-depth look at how a juice cleanse affects your body.

The Basics of Juice Cleansing

There are a few core components that make up a standard juice cleanse:

  • Drinking 6-8 glasses of fresh, raw fruit and vegetable juice per day
  • Eliminating all solid foods, dairy, meat, and other animal products
  • Drinking plenty of water (in addition to the juices) to stay hydrated
  • Typically lasting 3-5 days, up to 10 days maximum

Juices used in cleanses are 100% raw and unpasteurized. Some cleanses permit the use of nut milks, broths, or smoothies in addition to vegetable and fruit juices. Popular juice cleanse programs include BluePrint Cleanse, Juice Press, and Liquid Diet. Cleansers aim to flood the body with antioxidants, vitamins, minerals, and phytochemicals while eliminating processed foods and giving the digestive system a break.

Weight Loss Effects

One of the primary reasons people try juice cleanses is to lose weight quickly. By consuming only fresh fruit and vegetable juices and eliminating solid foods for multiple days, a dramatic calorie deficit is created. This will inevitably lead to weight loss, at least in the short-term.

For example, someone who normally eats 2,000 calories per day would consume around 1,000 calories on a juice cleanse. This calorie deficit of 1,000 calories per day would theoretically lead to 2 pounds of weight loss per week on a cleanse. However, much of the initial weight lost is water weight, which will likely be regained once solid foods are reintroduced.

Daily Calories Calorie Deficit Expected Weight Loss Per Week
2,000 (normal diet) 1,000 (on juice cleanse) 2 lbs

While juice cleanses can give the number on the scale a dramatic drop in the short-term, much of this weight is likely to return. Crash dieting measures like juice cleanses lead to a reduction in muscle mass and a slower metabolism over time, making long-term weight loss more challenging.

Detoxification Effects

Detoxification, or cleansing the body of toxins, is frequently touted as a benefit of juice cleanses. Proponents claim that eliminating solid foods for several days allows the digestive system to rest and the liver to more effectively eliminate toxins.

While juicing does provide abundant nutrients from fruits and vegetables that can benefit health, there is little scientific evidence that juice cleanses actually remove toxins from the body. The liver and kidneys already work 24/7 to detoxify the body of harmful substances.

That said, avoiding processed foods, alcohol, and other toxic exposures during a cleanse certainly reduces incoming toxins. And flooding the body with antioxidants from fresh produce may also temporarily support the body’s detoxification processes to some degree.

Effects on Digestion and Energy

Going several days without solid foods can temporarily relieve digestive issues like gas, bloating, and constipation by giving the GI tract a break. However, as soon as solid foods are reintroduced, digestive troubles often return.

Cleanses also lead to a dramatic drop in calories, protein, fiber, and healthy fats, which can cause fatigue, headaches, irritability, and low blood sugar levels. While cleansers may feel euphoric and energetic for the first day or two, most experience crashes as their bodies adjust to the low calorie intake.

Nutrition-Related Effects

Juice cleanses pack in vitamins, minerals, and phytochemicals from fruits and vegetables. However, they lack many other crucial nutrients:

  • Protein: Lack of protein can lead to muscle breakdown.
  • Healthy fats: Fats help absorb key fat-soluble vitamins and support hormones.
  • Fiber: Fiber keeps the GI tract healthy and helps control blood sugar.
  • Calcium: Inadequate calcium can take a toll on bone health.

While juice provides concentrated amounts of some nutrients, a balanced whole foods diet with adequate calories supplies far superior nutrition overall.

Long-Term Effects

There is very limited research on the long-term effects of juice cleanses. However, a few potential long-term consequences include:

  • Slower metabolism: Severely restricting calories slows metabolism.
  • Nutrient deficiencies: Lack of protein, fiber, fats, and other nutrients can develop over time.
  • Disordered eating: Cleanses may spur unhealthy eating habits for some people.
  • Weight cycling: The weight lost from cleanses often comes back, leading to yo-yo dieting.

For most people, juice cleanses do not lead to sustainable benefits and may undermine health and metabolism over time. But with medical guidance, they may have a therapeutic role in some circumstances.

Potential Benefits

Some potential benefits of juice cleanses for certain individuals include:

  • Weight loss: Cleanses lead to a substantial short-term calorie deficit.
  • Break from processed foods: Cleanses eliminate additives, refined carbs, etc.
  • Flood of nutrients: Juices provide concentrated amounts of vitamins and minerals.
  • GI tract rest: The digestive system gets a brief break.
  • Higher veggie intake: Juices make it easy to consume abundant vegetables.

However, these benefits are usually temporary and can come at a health cost for many people if cleanses are prolonged or repeated too frequently.

Potential Dangers

Some potential dangers of juice cleanses include:

  • Nutrient deficiencies: Cleanses are lacking in protein, fatty acids, calcium, and other essential nutrients.
  • Weight cycling: The weight lost from cleanses often comes back as soon as solid foods are reintroduced.
  • Hypoglycemia: Low calorie, carbohydrate-rich juices can cause blood sugar crashes in some individuals.
  • Dehydration: Without adequate water, cleanses can lead to dehydration.
  • Metabolic slowdown: Severely restricting calories can slow the metabolism.

People with certain medical conditions like diabetes or eating disorders should avoid cleanses altogether and consult a doctor about other ways to improve health.

Conclusion

Juice cleanses promote quick weight loss and flood the body with concentrated fruits and vegetables. However, they are very low in calories and lack essential nutrients that the body relies on. Cleanses may provide a short-term energy boost and sense of euphoria, but often lead to fatigue, headaches, and other symptoms as the body struggles with the very low calorie intake.

While juice cleanses are unlikely to cause lasting harm in healthy people if only done for a few days, they do not provide sustainable benefits. The weight lost usually comes back quickly and cleanses may undermine long-term health by slowing metabolism and contributing to disordered eating patterns.

For those looking to lose weight and improve health, a whole foods diet rich in fruits, vegetables, lean proteins, whole grains, and healthy fats provides superior, sustainable nutrition without the risks of crash dieting.