You have decided to try fasting because of the many potential health benefits. As you start learning more about it, you see fasting is much more simply not eating. There are several different ways to approach a fast, so how do you know which is best for you?

What should you consider before choosing a fasting method to meet your goals?

Speak to Your Doctor

A great place to start if you want to begin fasting is to speak to your doctor. This is particularly important if you have any medical conditions or take medications. Fasting may be contraindicated or need to be modified for people with specific health concerns. Your doctor is the best source of information to evaluate what is right for you.

Type of Fasting

As we mentioned, there are many different types of fasting. [1] Although all involve some degree of not eating, how often and for how long will depend on the type of fast.

There are two general categories for fasting:

• Intermittent fasting: less than two days
• Prolonged or periodic fasting: greater than two days

Within these two categories there are also different methods. For intermittent fasting the different methods that exist include:

• Time restricted eating.

This type of fasting involves breaking up your 24-hour day into periods of feeding and fasting. Common methods include eating within an 8 hour window and fasting for 16 hours, sometimes called the 16:8. Or the circadian method where you eat within a 12 hour window and fast for 12 hours.

• 5:2 Method

This fasting method involves fasting two days a week while eating normally five days per week. The two fasting days might include some caloric intake, usually restricted to 500-600 calories or less.

• Alternate day fasting.

Alternate day fasting involves fasting every other day. Like the 5:2 method, the “fasting” days might involve consuming a small number of calories.

Prolonged or periodic fasting includes two primary methods: 

• Water fasting.

Nothing is consumed except water for several days. This is challenging for most people to stick with.

• Fasting mimicking diet.

Fasting with food. This is a diet designed to provide specific macronutrient ratios that help mimic the effect of fasting in the body. This diet restricts protein, glucose, and nutritious fats.

Once you understand the different types of fasting, you can then use this information to determine what method might work best for you.

Assess Your Goals and Lifestyle

When choosing the best fasting method, you want to first understand your personal goals with fasting. Are you trying to lose weight or are you more focused on the health benefits of fasting? [2] Although you can have both goals, focusing on one can help guide you in a specific direction.

You should also consider your lifestyle. Here are a few questions you can ask yourself when choosing the best fasting method:

• Based on your current lifestyle, are you able to go a day or more without food?
• Do you still need to prepare food for others even if you are fasting?
• Are you involved in any intense physical activity?
• Do you have any social commitments that involve food coming up?
• Do you have any scheduling conflicts that might interfere with fasting?

Once you identified any possible challenges you might have, it is time to choose a fasting method.

Choose the Best Fasting Method

Although it might be tempting to dive in to see fast results, for most people it is probably best to start slowly. Fasting “beginners” usually dip their toe in by starting with a 16:8 or even a 12:12 protocol.

This method is a bit simpler and easier to stick with because most of your fasting takes place while you are asleep. For most people following a 16:8 protocol just involves skipping breakfast or eating it a bit later.

Once you get the hang of fasting and see how it makes you feel, you can move on to more prolonged methods. The 5:2 diet is a great way to start fasting for longer periods and seeing even more health benefits. Remember on the “feeding” days you shouldn’t go crazy with your diet. Feeding days should involve a well-balanced diet to make up for nutrients missed on fasting days. If you are binge eating on non-fasting days, no matter how perfectly you are fasting, you won’t see the results you are looking for.

For those who truly want to improve their metabolic health a prolonged fast might be appropriate. Longer fasts may have more pronounced health benefits when compared to shorter fasts. You can learn more about some of these additional benefits for weight loss, longevity, and mental health here. [3]

Who Should Not Fast

Fasting is not for everyone. Most healthy people should be able to fast without any significant side effects. But, a few groups who should avoid fasting include:

• Pregnant women
• Women who are actively trying to become pregnant
• Lactating women
• People taking certain medications
• History of eating disorders
• Prone to severe hypoglycemia
• People over the age of 70

If you belong to one of these groups, consider reaching your health goals by eating a well-balanced diet instead.

Tips for a Successful Fast

No matter which method you choose, there are a few things you want to implement for any successful fast.

First, stay hydrated. We get a lot of water from the food we eat, therefore if you are fasting you will need to make up for this lost water. If you start to feel lightheaded consider adding electrolytes to your water or sipping on bone broth, which can really help.

Second, listen to your body. There is no reason to push a fast for longer than you are comfortable with. If you start to feel sick, extremely dizzy, or shaky consider ending your fast.

Finally, keep busy on fasting days. Keeping your mind off food will help the day and the fast go much faster.

Fasting is a great method to help with weight loss and improving health. Choosing the right method for you can take a bit of trial and error, but it can help you improve your health and reach your goals.