The practice of fasting has been regaining momentum during previous years. Athletes are using it for body composition and performance improvement goals. Nutrition-savvy doctors are using it to improve medical outcomes. And others are using it as a weight loss approach instead of chasing diets.

Fasting is not a fad, nor is it anything new. Fasting dates back to our ancestors, when it wasn’t necessarily a choice, or when it was practiced for religious reasons. Buddhists practice fasting as a means of building a disciplined regimen that assists the meditation practice. Many other religions use fasting as a way to show abstinence and gratitude.

Perhaps you’ve tried fasting before and were not successful. The truth is, there are many types of fasting. The trick is to find the fasting method that works for you and is geared towards the outcomes you desire.

Related: 5 Principles of Spartan Nutrition

Types of Fasting

What is the best fasting diet? It depends on you and your goals. Here are four methods to fasting that anyone can use:

The 12-Hour Fast

How to: The simple practice of not eating for 12 hours following the time you finish your last meal of the day. For example, if you finish dinner at 6pm, you will not have anything to eat until 6am the following morning.

Pros: This daily ritual is easy to implement because many people do it naturally.  A bulk of the time spent fasting occurs when we are sleeping. The 12 hour fast can be implemented immediately.

Cons: None

Take-aways: This short-duration fasting period should be seen as a daily ritual that we all practice as a minimum.  The bulk of this fast happens when we are sleeping and allows our digestive system to rest, digest, and repair itself.   

16:8 Fasting

How to: The 16:8 fasting pattern describes the window of time in which you are fasting (16 hours) and eating (8 hours). The rules are simple, you have an 8 hour window of time daily in which you can eat as you desire. Once you hit the 8 hour mark, you’re done until the following day.

Pros: The 16-hour length of time allows your body additional time each day to promote the utilization of stored energy (aka fat) as a fuel source. Most people, regardless of what they eat during the 8 hour window, find reduced overall body fat due to this process. The reduced pressure of not having to consume anything during the first hours after waking can also help with stress reduction.

Cons: You will need to take time in the beginning to pay attention to the clock. Getting on a schedule (such as first meal at 11am and final meal by 7pm) is important, but can easily be a challenge if you let the evening get away from you. Intense training, in the beginning only, may be affected as you adjust to not have fuel before or directly after.

Take-aways: Optimal nutrition should always be a focus of your food choices. Minimizing processed foods and eating whole sources is important, but this 16:8 pattern can help promote stored fat use and healthy cell turnover regardless. This pattern can be a great start for someone looking to focus less on what they are eating, and more on the timeframe in which they eat.

Related: Do You Need to Count Calories to Lose Weight?

24-Hour Fast

How to: This fast requires a 24-hour fasting window from the time of your last meal. For example, if you finish dinner at 6pm on Thursday, you will not eat again until 6pm on Friday.

Pros: As with the 16:8 pattern, the 24 hour fast elongates the time in which your body is forced to use stored energy as fuel. If done once per week, in addition to a regular healthy eating plan and activity, the 24 hour fast can help increase the rate of fat loss. Bonus: Not eating for 24 hours means not having to think about what to eat or meals to pack, while saving money on food.

Cons: Not eating can be mentally challenging. Hunger pangs and the desire to eat will still occur at times when you normally would be eating. Don’t worry, they will pass. This fast will also affect those that live with you, such as spouse and kids. It’s important to plan ahead for this by having a conversation with them. Will you still need to cook dinner that night or can your spouse take over? Prepping dinner and not being able to eat it will be a game of mind over matter. Intense training may be affected, so planning the 24-hour fast on a rest day often helps.

Take-aways: The 24 hour fast is a great way to promote additional body fat loss. The lack of fuel can affect training intensity and duration, although athletes of all background find that they can train just as they would on non-fasting days. The key is to plan smart during your first few trials and have them occur on rest days. As you learn how your body feels during the fast, you can then begin to add training sessions if desired.

Multiple-Day Fasting

How to: Multiple-day fasting is anything beyond a 24-hour fast period. Some people will consume water, tea, black coffee, water with pink Himalayan sea salt, or bone broth during these times. The recommended type of fluid you take in will vary by person and be based on the length of your fast. A general daily multivitamin is also suggested to cover your bases.

Pros: Increased fat turnover, increased (natural) cell turnover, natural detoxification, and a reset of your hunger scale.

Cons: Mentally challenging, can affect the lives of those around you, can affect your training capabilities, and may induce more stress on some individuals.

Takeaways: Multiple-day fasting can be done for various reason and for various lengths. Some people enjoy a 7-10 day fast once annually as it has been suggested to promote apoptosis (natural cell death) as an approach to cancer prevention. Some enjoy a 3 day fast once per month as a re-set. Healthy multiple-day fasts can be used as an approach to “recover” from events such as holidays or vacations (although this can be a slippery-slope towards disordered eating, so be cautious).

Recap: Types of Fasting

No matter what you decide is the best fasting diet for you, fasting can be done by almost anyone, anytime, anywhere. It takes minimal planning: Just don’t eat. It takes no money: You don’t have to buy any special foods or supplements. You actually save money! It takes no time: No food prep, no food packing, not even a lunch break. It takes no education (for the most part): You don’t have to learn about nightshades, gluten, or any other special categories of food.

Do it Spartan style: Eating (or not eating) shouldn’t be difficult. Eat, or don’t. But when you don’t, make it whole foods from real sources, and mostly plants.