Juicing has become an increasingly popular way for people to get more nutrients into their diets. With the rise of intermittent fasting, many people wonder if drinking juice during their fasting periods will break their fast. In this article, we’ll take an in-depth look at whether or not juicing breaks a fast.
What is Intermittent Fasting?
Intermittent fasting (IF) is an eating pattern that involves cycling between periods of eating and fasting. Some popular intermittent fasting methods include:
- 16/8 method: Fast for 16 hours per day, eat during an 8 hour window.
- 5:2 diet: Eat normally 5 days per week, restrict calories to 500-600 per day 2 days per week.
- Alternate day fasting: Fast or restrict calories every other day.
- Eat-stop-eat: Do a 24 hour fast 1-2 times per week.
No matter the specific protocol, the goal of intermittent fasting is to give your body an extended break from eating to tap into fat stores for energy. This can help with weight loss, insulin sensitivity, and other health markers when done consistently.
What is Juicing?
Juicing refers to extracting the nutritious fluids and vitamins from fruits and vegetables. This is done by running produce through a juicer machine that separates the pulp and fiber from the juices.
Some benefits of juicing include:
- Increased nutrient absorption – Juices are absorbed faster than solid foods.
- Easy way to get veggies – Allows you to consume vegetables you wouldn’t normally eat.
- High in antioxidants – Juicing extracts live enzymes and antioxidants.
People juice fruits and vegetables either as a meal replacement or as a supplement to an overall healthy diet. It has become popular among intermittent fasters looking for an easy way to get nutrients while fasting.
Does Juicing Break a Fast?
Whether or not juicing breaks a fast depends on your fasting goals and the ingredients in your juice.
For Calorie Restriction
If your goal with intermittent fasting is calorie restriction for weight loss, juicing will likely break your fast.
Most fruit and vegetable juices contain around 100-200 calories per 16 oz serving. Even though juices don’t have the same fiber content as whole produce, they can still provide a substantial number of calories in liquid form.
Drinking juice adds calories and sugar into your system, which means your body needs to produce insulin and digest, even if it’s natural sugar from fruits and veggies. This would take you out of a fasted state.
For Metabolic Switch
If your goal with intermittent fasting is to achieve the metabolic switch from burning glucose to burning fat, juicing is less likely to break your fasted state.
Though juices contain calories and sugars, they don’t seem to significantly impact insulin or glucose levels compared to solid food. One study found that juice did not raise insulin, glucose, or cholesterol levels in a similar way to solid carbohydrates.
Your body can still access fat stores for energy while absorbing juices. So drinking juice may not completely disrupt the metabolic adaptations of fasting.
For Gut Rest
If your goal with intermittent fasting is gut rest and reducing digestion, juicing will break your fast.
Even though juice doesn’t require the same digestive process as solid food, your gut still has to work to break down and absorb the nutrients. Juicing defeats the goal of giving your GI tract an extended break.
Impact of Different Juice Ingredients
Not all juices are created equal when it comes to breaking a fast. Some ingredients are more likely to disrupt your fasted state.
Fruit juices like orange, apple, grape, mango, etc. are high in natural sugars. The concentrated sugars could spike blood glucose and insulin, taking you out of fasted mode metabolically.
Vegetable juices like spinach, kale, carrot, celery, etc. have fewer sugars and thus less impact on insulin. However, they still contain calories that could technically break a calorie-focused fast.
Root Vegetable Juices
Root vegetables like beet or sweet potato are higher in starch and sugar compared to greens. Their juices may be more likely to disrupt a fast metabolically.
Some juice fasts or cleanses involve drinking only juices for an extended period. These are too high in calories to allow fasting benefits and will take you out of a fasted state.
Bone broths contain protein and some calories, but generally will not stimulate insulin or glucose. So plain broths are less likely to break a fast than fruit or veggie juices.
Recommended Juice Intake While Fasting
Given the nutritional content of most juices, here are some recommendations for juicing during intermittent fasting windows:
- Limit juice intake to 4-8 oz per day maximum
- Consume juices earlier in the fasting window
- Stick to low sugar vegetables like spinach, kale, cucumber
- Avoid pure fruit juices
- Dilute juices with water, coconut water, or plain tea
Consuming small amounts of low-sugar juices earlier in your fast is least likely to impact your progress. Juice in moderation as a supplement, not a meal replacement.
Does Juicing Help or Hurt Fasting?
Based on the evidence, here is a summary of how juicing affects different fasting goals:
|Does Juicing Help or Hurt?
|Weight loss via calorie restriction
|Hurts – adds calories
|Metabolic switch to fat burning
|May help or hurt – impacts insulin variably
|Hurts – requires digestion
If your priority is calorie reduction or gut rest, juicing will likely take you out of a fasted state. If your focus is the metabolic switch, judicious juicing may be permissible, but limit intake.
Should You Juice While Intermittent Fasting?
Due to its impact on fasting goals, regular juicing during fasting windows is not recommended.
Occasional use of low-sugar vegetable juices in small amounts may be alright for some people. But juicing should not replace water, black coffee, tea, or zero-calorie beverages as your main liquids when fasting.
If you want to juice, it’s best done during your feeding period. Juice can be a great way to hydrate and get extra nutrients after a workout or with a meal.
Some better options during fasting periods include:
- Unsweetened tea
- Black coffee
- Carbonated water
- Apple cider vinegar drinks
- Bone broth
These provide hydration and some benefits without disrupting your fasted state.
Juicing is a double-edged sword when it comes to intermittent fasting. While juices can provide beneficial vitamins and minerals, they may also break your fast depending on the ingredients and your fasting goals.
For those doing intermittent fasting for calorie restriction or gut rest, it’s best to avoid juicing during the fast. For those focused on the metabolic switch, occasional low-sugar vegetable juices in small amounts may be ok.
Make sure to listen to your body and how it reacts if you try juicing while fasting. Pay attention to hunger, satiety, energy levels, and other factors to assess its impact. Juicing during feeding windows is likely a better option for most people.
At the end of the day, juicing should not replace zero-calorie beverages like water, plain tea, and black coffee as your go-to’s for intermittent fasting. Prioritize these unsweetened fluids as much as possible when fasting for best results.