Which Drinks to Sip and Skip While Fasting

Fasting can take many forms and serve many purposes, like being a component of religious observance and preparing your body for a medical procedure. Methods of fasting vary as well, with some encouraging you to consume nourishing fluids like juices, smoothies, and broths, and others exclusively allowing water.
The best way to ensure a safe and effective fast is to plan ahead based on your specific intentions and needs, stocking your kitchen accordingly. Here, learn about the types of liquids allowed on various types of fasts along with tips for fasting safely.
Intermittent Fasting vs. Liquid Diets
Then there are full liquid diets, which while not exactly fasting, are another way people choose to limit their food consumption. And — spoiler alert — they’re typically neither healthy nor sustainable.
With any kind of restriction-based diet, it’s best to loop in your doctor or a registered dietitian who can guide and monitor you to ensure you’re getting adequate nutrition.
Liquids to Drink While Fasting
Again, various fasting plans exist and carry their own guidelines — some of which can be supportive of an overall healthy lifestyle and others less so.
Several other fluids are generally acceptable during periods of fasting, such as:
- Black coffee
- Unsweetened tea
- Seltzer water
- Zero-calorie electrolyte drinks without artificial sweeteners
Tips for Fasting Safely
No matter what type of fast you’re following or why you’re doing it, it’s important to follow a few key safety tips.
- Consult your healthcare provider first. They can help you prepare with any necessary adjustments to medications that must be taken with food. Fasting is not a healthy choice for a number of people, often including those with diabetes, chronic kidney disease, pregnant and breastfeeding people, and people with a history of disordered eating.
- Hydrate. Research supports the importance of hydrating well before, during, and after fasting to support your body’s various needs and keep your energy up during periods of calorie restriction.
- Reintroduce food carefully and methodically. When your fast is over, incorporate food into your eating plan slowly and gradually with small portions of easy-to-digest fruit and other light foods. Consider medical supervision when breaking lengthier fasts to prevent any complications as you reintroduce solid foods.
- Start small with intermittent fasting. If you decide to give intermittent fasting a try, start with a smaller restriction window to see how your body adjusts. From there, you can extend the window gradually to suit your needs and goals. And when you’re in a non-fasting period, prioritize healthy, whole foods to ensure you get the balanced nutrition your body needs.
- Stick to gentle exercise. While more research is needed to give specific physical activity recommendations for periods of fasting, Cleveland Clinic recommends you steer clear of intense workouts, like breaking your personal records. Also, pay attention to cues from your body that you need a break or a rest day, like dizziness or nausea.
The Takeaway
- People fast for a number of reasons, including religious observance, preparation for a medical procedure, and weight loss. There are also different forms of fasting, like intermittent fasting and adhering to a full-liquid diet. Each type has different guidelines for what you can and can’t consume during each fasting period.
- Depending on the plan you’re following, you may be allowed to consume water, black coffee, unsweetened tea, seltzer water, and zero-calorie electrolyte drinks with no sweeteners while fasting.
- Before you start a fast, make sure you consult a healthcare professional who can help ensure you are following a plan that is safe for you.
- 6 Tips for Fasting Safely. Cleveland Clinic. March 5, 2024.
- Nutrition and healthy eating. Mayo Clinic. March 8, 2025.
- What Is Intermittent Fasting? Cleveland Clinic. January 26, 2026.
- Detox diets and cleanses: What our clinicians have to say. Kaiser Permanente. April 2, 2023.
- I'm trying to lose weight. Could protein shakes help? Mayo Clinic. February 27, 2025.
- Full Liquid Diet. MedlinePlus. July 24, 2024.
- When to Stop Eating and Drinking. UCLA Health. July 2023.
- Sunardi D et al. Assessment of water consumption during Ramadan intermittent fasting: Result from Indonesian cross-sectional study. Frontiers in Nutrition. July 25, 2022.
- Fasting: How Does It Affect Your Heart and Blood Pressure? Cleveland Clinic. February 3, 2020.
- Is It Safe to Work Out While You’re Fasting? Cleveland Clinic. March 6, 2024.

Karen E. Todd, RD, CSCS, EP-C, CISSN
Medical Reviewer
Karen E. Todd, RD, CSCS, EP-C, CISSN, is a registered dietitian and strength and conditioning specialist committed to evidence-based education in lifelong wellness, sports nutritio...

Brynne Chandler
Author
Brynne Chandler is an avid runner, swimmer and occasional weight-lifter who fell in love with all things fitness related while writing TV Animation in Los Angeles. Her passion for ...