Fasting can take many forms and serve many purposes, from showing respect during periods of religious observance to preparing your body for a medical procedure. Methods of fasting vary as well, with some encouraging the consumption of nourishing fluids like juices, smoothies, and broths, and others allowing water exclusively.
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.
Intermittent Fasting vs. Liquid Diets
Fasting is simply the practice of depriving your body of food for a set amount of time or until you achieve a particular goal, according to Cleveland Clinic. There are many types of fasts and numerous reasons for practicing any of them, but the priority when fasting for overall health is ensuring you’re not depriving yourself of crucial nutrients.
Intermittent fasting is touted as a way to regulate your weight, support your heart health, and quell inflammation, according to Mayo Clinic.
While there are several styles of intermittent fasting, each one requires restricting eating to certain windows of time each day or to certain days in a given week. For example, some people who do intermittent fasting only eat between noon and 8 p.m. each day. According to Cleveland Clinic, this regimen is one that can be maintained indefinitely, as it doesn’t deprive the body of vital nutrition for lengths of time that could be detrimental to one’s health.
Meanwhile, there are several circumstances where you may need to adhere to a full liquid diet for a short period, according to MedlinePlus. For instance, full liquid diets may be required prior to some medical tests and procedures, as well as immediately before and after certain surgeries. These diets are recommended and supervised by a healthcare professional to ensure that your nutrition needs are met during times of restriction.
Liquid diets, while not exactly fasting, are another way people choose to limit their food consumption.
Fad liquid diets, such as the “detoxifying” lemon juice, cayenne pepper, and maple syrup trend, should be avoided because they don’t provide complete nutrition, according to Kaiser Permanente.
Relying too heavily on prepared products like protein shakes for extended periods of time can also lead you to miss out on important health benefits provided by whole foods, according to Mayo Clinic.
Liquids to Drink While Fasting
To maintain a fasting state, it’s important to only drink zero- and minimal-calorie beverages, according to Cleveland Clinic. Water is the most important fluid to consume while fasting to maintain your energy and prevent dehydration, which can contribute to hunger headaches, according to Cleveland Clinic.
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
If you’re fasting for medical reasons, consult your healthcare provider for specific instructions regarding what you can and cannot consume before and after your scheduled procedure.
For instance, surgical procedures often require full fasting, restricting water consumption along with other drinks often allowed while intermittent fasting, for two hours prior to when you’re scheduled to arrive at the hospital, according to UCLA Health. But for eight hours up to your arrival time, you can enjoy all the drinks listed above, plus clear juices like apple juice and white cranberry juice (even though they contain calories).
Tips for Fasting Safely
If you’re interested in fasting for whatever reason, be sure to consult your healthcare provider first, Cleveland Clinic recommends. They can help you prepare with any necessary adjustments to medications that must be taken with food. People with diabetes, people with chronic kidney disease, pregnant and breastfeeding people, and people with a history of disordered eating are discouraged from fasting.
Based on research, it's recommend that you hydrate well before, during, and after fasting to support your body’s various needs and keep your energy up during periods of calorie restriction.
When it comes time to break your fast, consuming calories that take your body out of its fasted state, Cleveland Clinic recommends reintroducing food 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.
If you decide to give intermittent fasting a try, experts recommend starting with a smaller restriction window of just a few hours each day to see how your body adjusts, according to the University of Michigan School of Public Health. 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.
Finally, keep your body active during times of fasting, but stick to gentle movement like walking and stretching, avoiding overly strenuous exercise when your energy is naturally low, Cornell Health recommends.
