Intermittent fasting has become an increasingly popular diet and lifestyle approach for weight loss, health, and longevity. Juicing, which involves extracting the nutritious juice from fruits and vegetables, is also gaining popularity among health-conscious individuals. But can these two regimes be combined? Is juicing allowed during intermittent fasting periods? In this comprehensive guide, we’ll explore the pros and cons of juicing while intermittent fasting to help you determine if it’s right for your goals.
What is Intermittent Fasting?
Intermittent fasting (IF) is an eating pattern that involves cycling between periods of fasting and eating. Rather than restricting what you eat, it focuses on when you eat. The most common IF approaches involve daily 16-hour fasts or fasting for 24 hours, twice per week. During the fasting periods, you can consume water, black coffee, and other non-caloric beverages. The eating periods vary based on the specific IF plan.
Research shows that IF offers a variety of potential benefits, including:
- Weight loss – By restricting calories and meal frequency, IF makes it easier to reduce calorie intake which can lead to weight loss.
- Reduced inflammation – Fasting periods give the digestive system a rest and are associated with lower markers of inflammation.
- Improved insulin sensitivity – IF can help improve the body’s response to insulin and blood sugar control.
- Heart health – Some research indicates IF may reduce blood pressure and LDL or “bad” cholesterol.
- Brain health – IF may boost the production of proteins that protect brain cells and improve cognitive function.
- Anti-aging effects – Studies suggest fasting triggers regenerative processes that may counteract disease and aging.
However, research is still emerging on the long-term effects of IF. It’s not suitable for everyone, so check with your healthcare provider before trying intermittent fasting.
What is Juicing?
Juicing refers to extracting the nutritious liquid from fruits and vegetables, while removing the fiber. This is typically done using a juicer appliance. The resulting juice contains most of the vitamins, minerals, and plant compounds from the produce used.
Some of the proposed benefits of juicing include:
- Increased nutrient absorption – The removal of fiber may allow for greater absorption of some nutrients.
- Convenient nutrition – Juicing lets you easily consume vegetables and fruits on-the-go.
- Weight loss aid – Replacing higher calorie foods with low-calorie juice may promote weight loss.
- Detoxification – Juicing fans claim it can remove toxins, reduce inflammation, and cleanse the body, but evidence is lacking.
- Disease prevention – The vitamins, antioxidants, and phytochemicals in juice may help prevent conditions like cancer and heart disease.
However, juicing also has some drawbacks. The fiber is removed during juicing, which eliminates many of the gut health and satiety benefits of whole fruits and veggies. Juice is also not as filling as solid food and contains natural sugars without the fiber, so it can spike blood sugar. Drinking too much fruit juice may also lead to excess calorie intake.
Is Juicing Allowed During Intermittent Fasting?
Whether or not you can drink juice during intermittent fasting depends on the specific rules of the IF plan you are following. Here are some general guidelines:
- Water fasting – Most fasting regimes allow only water, black coffee, tea, and other non-caloric beverages during fast periods. Juice would break this fast.
- 16/8 or time-restricted feeding – Whole fruit and veggie juice likely ok, but may spike blood sugar. Limit juicing to eating window.
- 24-hour fasting – Juice should be avoided during the 24-hour fasting period.
- 5:2 diet – Juice should be avoided during the two fasting days of this approach.
- Alternate day fasting – Juicing is allowed on feed days but avoided on fast days.
If your goal for intermittent fasting is ketosis or fat-burning, it’s best to avoid juice as the natural sugars will disrupt these processes. Even if juice is allowed, you may want to limit intake to a small glass, avoiding high sugar fruits like oranges or apple juice.
Benefits of Juicing While Intermittent Fasting
There are some potential benefits that make juicing an appealing option on feed days of intermittent fasting:
- Nutrient intake – Juicing makes it easy to flood your body with vitamins, minerals, and antioxidants during your eating window.
- Vegetable consumption – Juicing can help increase veggie intake for those who struggle to eat enough whole vegetables.
- Weight loss – Replacing higher calorie foods or beverages with fresh juice supports weight loss goals.
- Energy boost – The natural sugars in juice can help boost energy after fasting periods.
- Hydration – Juice provides hydration, electrolytes, and nutrients lost after water fasting.
If you break your fast with juice, stick to low sugar vegetables and greens. You can also dilute fruit juices with water or club soda to minimize sugar content.
Drawbacks of Juicing While Intermittent Fasting
There are also some potential downsides to consider with juicing during intermittent fasting periods:
- Blood sugar spikes – Juice can cause rapid rises and falls in blood sugar without protein or fat to balance it out.
- Hunger pangs – The lack of fiber may make juicing less satiating, leading to hunger and overeating.
- Loss of nutrients – Fiber and some nutrients are removed during juicing.
- Slowed metabolism – The sugar in juice may inhibit lipolysis and ketosis from fasting.
- Tooth decay – The acidity of juice may erode tooth enamel over time, especially without saliva flow while fasting.
To counter these issues, limit juice to one small glass, dilute with water or club soda, and focus on low glycemic vegetables. Be sure to brush teeth after drinking juice while fasting. Juicing is also not recommended for those with diabetes or blood sugar regulation issues.
Best Juices for Intermittent Fasting
If you choose to include juicing in your intermittent fasting plan, these are some of the best juice options:
Vegetable juices provide nutrients without spiking blood sugar. Some good options include:
- Spinach or kale
Low Sugar Fruit Juices
For a touch of sweetness, you can add small amounts of these lower glycemic fruits:
- Berries – blueberries, raspberries, blackberries
- Stone fruits – peaches, plums, nectarines
Juices made with herbal extracts add flavor without calories or sugar:
- Lemon juice
- Chamomile tea
Sample Juice Blends
Try these juice combos for intermittent fasting:
- Cucumber, celery, kale, lemon
- Carrot, beet, ginger shot
- Spinach, apple, parsley
- Tomato, broccoli, garlic
- Celery, lime, mint
Juicing vs. Smoothies for Intermittent Fasting
What about smoothies? They blend the entire fruit or vegetable, including fiber. Here’s how smoothies compare to juicing:
|Extracts liquid only||Leaves fiber intact|
|More nutrient absorption||Slower nutrient absorption|
|Less satiating||More filling|
|Quick blood sugar spike||Blunted blood sugar response|
|Lower in calories/carbs||Higher in calories/carbs|
For intermittent fasting, smoothies are generally a better option than juices. They are more likely to keep you full and satisfied during your eating window without an intense sugar crash after. But limit fruit and add protein to your smoothies to best support fasting.
Tips for Juicing During Intermittent Fasting
Here are some tips to follow if you choose to incorporate juicing into an intermittent fasting plan:
- Only juice during eating windows
- Avoid or limit fruit juices for lower sugar
- Focus on low glycemic vegetable juices
- Dilute fruit juices with water, club soda, or ice
- Add protein powder or nut butter to juices for satiety
- Drink juice alongside whole foods for balanced meals
- Limit juice to one small glass per day
- Brush teeth after drinking acidic juices
- Monitor blood sugar response and hunger levels
Intermittent Fasting Juicing Sample Schedule
Here is a sample juicing schedule for a typical 16:8 intermittent fasting protocol:
7:00 am – Wake up and drink 16 oz water
11:00 am – Break fast with veggie juice or smoothie
12:00 pm – Eat balanced lunch with juice on the side
3:00 pm – Nutritious afternoon snack
6:00 pm – Drink herbal juice or dilute fruit juice before dinner
8:00 pm – Finish eating window with healthy dinner
8:00 pm to 7:00 am – Fast with only water, tea, or black coffee
The Bottom Line
Deciding whether to include juicing in an intermittent fasting plan is a personal choice. While juice can provide a surge of nutrients, vitamins, and antioxidants, it may also cause unstable blood sugar. Most fasting regimes only allow calorie-free beverages like water, tea, and black coffee during fasts. On feed days, juice is acceptable, but limit intake to a small amount and focus on low sugar vegetable juices. For most people, smoothies are likely a better option than juices while intermittent fasting due to their fiber and protein content. As with any diet change, it’s wise to experiment, pay attention to how you feel, and modify your approach if needed.