A juice fast while following a ketogenic diet may seem counterintuitive, but it is possible with some modifications. In this article, we’ll explore whether and how you can successfully combine juicing and keto.
What is a Juice Fast?
A juice fast involves consuming only freshly extracted fruit and vegetable juices for a period of time, usually ranging from 1-7 days. The goal is to flood the body with vitamins, minerals, phytochemicals, and enzymes while giving the digestive system a rest.
Juice fasts are low in protein, fat, and fiber since the fibrous pulp is strained out during juicing. The main calories come from fruit sugars and carbohydrates.
What is the Ketogenic Diet?
The ketogenic or “keto” diet is a very low-carbohydrate, high-fat diet designed to induce nutritional ketosis. In this metabolic state, the body switches from primarily burning glucose to burning fat and ketones for fuel.
Ketosis is achieved by restricting net carbs to 20-50 grams per day, with higher fat and moderate protein intake. The reduction in carbs helps lower insulin levels so the body can access stored fat for energy.
Why Juice Fasts and Keto Seem Incompatible
At first glance, doing a juice fast on keto may seem impossible because of the diet’s strict low-carb parameters.
Here are some of the potential issues with combining juicing and keto:
- Fruit and veggie juices are high in carbs from natural sugars.
- Lower fiber and protein in juices can spike blood sugar.
- Lack of fat from juices can reduce ketones.
- Excess fructose from juices can halt ketosis.
Given these conflicts, doing a traditional, high-sugar juice fast would quickly kick you out of ketosis.
Is Juice Fasting Completely Off Limits on Keto?
Not necessarily. With careful planning, it is possible to do a modified juice fast while staying in ketosis. The key is choosing low-sugar vegetables and avoiding high-carb fruits.
Here are some tips for doing a modified juice fast on keto:
Focus on Low-Carb Vegetables
Choose greens like spinach, kale, chard, lettuces, and cruciferous veggies like broccoli, cabbage, and cauliflower as the base of your juices. Stick to veggies with 5 grams of carbs or less per serving.
Avoid High-Sugar Fruits
Fruit is tricky on keto, so avoid juicing high-sugar produce like apples, mangos, grapes, bananas, and citrus fruits. The natural sugars will add up quickly.
Add Healthy Fats
Since juices lack fat, incorporate healthy fats like avocado, coconut oil, flax oil, or MCT oil. You can make “fat bombs” with these to help maintain blood ketones.
Include Non-Starchy Vegetables
Add lower-carb veggies like asparagus, zucchini, bell peppers, onions, tomatoes, etc. This provides more variety of nutrients.
Supplement with Protein
To help prevent muscle loss, add keto-friendly protein powders like collagen, bone broth, or whey isolate. You can blend these into juices.
Test Ketones and Glucose
Use urine strips or a blood monitor to track your ketone and glucose levels. This will ensure you stay in ketosis.
Sample Juice Fast Menu on Keto
Here is a sample one-day juice fast menu on keto:
| Juice | Ingredients |
|---|---|
| Green Refresh | 1 cucumber, 5 leaves kale, 1 stalk celery, 1⁄2 lemon |
| Garden Green | 1⁄2 head lettuce, 1⁄2 cucumber, 5 leaves spinach, 1⁄2 avocado, ice |
| Spinach Celery | 1 cup spinach, 2 stalks celery, 1⁄2 lime |
| Detoxifier | 1⁄2 head cabbage, 1⁄2 bunch parsley, 2 carrots, 1 tsp. ginger, garlic clove |
| Keto Bomb | 1 tbsp. MCT oil, 1 tbsp. coconut oil, 1⁄2 avocado, 1 scoop collagen, ice |
| Green Zinger | 1 cucumber, 5 leaves kale, 1⁄2 lemon, ginger, garlic, cayenne |
This provides low-carb, keto-friendly vegetable juices along with healthy fats and protein supplements. Monitor your glucose and ketones to ensure you remain in ketosis.
Should You Exercise While Juice Fasting on Keto?
Light activity like walking, yoga, or gentle stretching is fine during a modified juice fast. However, intense workouts are not recommended since you may feel low on energy.
Listen to your body and don’t overexert yourself. Take it easy until you transition back to eating regular keto meals.
Potential Benefits of Juice Fasting on Keto
Despite the challenges, a modified juice fast while in ketosis can offer benefits like:
- Floods body with phytonutrients from vegetables
- Gives digestive system a rest
- Allows ketosis to burn fat stores for energy
- Eliminates cravings for unhealthy foods
- Reduces inflammation
- Improves mental clarity and focus
The key is constructing juices wisely to avoid disrupting ketosis.
Risks and Side Effects
Potential risks and side effects to be aware of with juicing on keto include:
- Kicked out of ketosis by excess carbs
- Blood sugar spikes if juices are high in fruit sugars
- Hunger and cravings due to lack of protein and fat
- Loss of electrolytes like sodium, potassium, magnesium
- Fatigue, dizziness, headaches from low calories
To minimize these risks, stick to low-carb vegetable juices, monitor your ketone levels, and supplement juices with healthy fats and proteins. Only juice fast for 1-3 days at a time.
Who Should Avoid Juice Fasts on Keto?
Juice fasts on keto are not recommended for certain groups, including:
- Children or pregnant/nursing women
- Those with gout or kidney problems
- People with eating disorders or body image issues
- Diabetics or others prone to hypoglycemia
- Anyone on medication affected by low calories/carbs
For these populations, even modified juice fasts could be dangerous and lead to complications.
Always consult your doctor before attempting a juice fast on keto, especially if you have any underlying health conditions.
Transitioning Back to Eating After a Juice Fast
Once your juice fast is over, it’s important to slowly transition back to solid keto foods. Here are some tips:
- Introduce broths, cooked veggies, eggs after 1-2 days of juicing
- Gradually increase protein intake and reintroduce healthy fats
- Eat smaller, lighter meals at first
- Chew food thoroughly and eat slowly
- Avoid heavy fat/protein meals right away
- Stay hydrated and watch for digestive issues
Give your body time to adjust back to solid foods. Pay attention to how you feel.
Conclusion
While juice fasting presents some challenges on the ketogenic diet, it is possible by selecting low-carb vegetables and avoiding high-sugar fruits. Monitor ketone and glucose levels, supplement with fats/protein, and ease back into keto foods after 1-3 days of juicing.
A modified juice fast while in ketosis may allow you to flood your body with nutrients and give your digestive system a break, without kicking you out of fat-burning mode. As always, consult your doctor, especially if you have any medical conditions.
