Fasting isn’t quite as simple as just not eating. There are several reasons why someone would fast – to lose weight, to fight disease, for spiritual/religious reasons, to balance hormones, or something else. Depending on the purpose–or the person–one type of fast might be more appropriate than another. Here are 6 different types of fasts and their respective purposes.

1. Intermittent fasting –  The benefits of intermittent fasting are many, and it’s listed first because it’s a smart, healthy long-term strategy. Essentially, you skip breakfast and only eat during a 6-8 hour window every day, i.e., from 2pm – 8pm. This gives your body (particularly the liver) time to process and eliminate toxins and sugars from previous meals. Generally, this takes at least 16 hours. It’s a great way to lose weight–or maintains weight–balance your hormones, re-establish insulin sensitivity and detox. Of course, it matters WHAT you eat during your intermittent fast (I recommend a ketogenic diet), but interestingly, it does NOT matter how much you eat–as long as it is within your 6-8 hour window.
2. 24-hour fast – It is common for people to do a 24-hour fast once per week as a sort of “reset” for their metabolism, as well as weight maintenance and the psychological sense that they are in control, rather than the food. It’s quite simple, really. Don’t eat any food and drink only water for 24 hours.
3. Juice fast – The time of this one can vary – it may be one day or even two weeks (or more). The idea is to continue to consume the important micronutrients you get from fruits and vegetables, but do it in a liquid-only format. This is often undertaken as an extreme weight loss attempt or as a way to “catch up” with any deficiencies in vitamins and minerals. My recommendation is that, if you are going to undertake a juice fast, go much heavier on the veggies–and particularly green veggies–than the fruits. The all-too-common juice-fast horror story is someone juicing a majority of fruit, then not balancing that with any other macronutrients, and essentially mainlining fructose for days at a time, leading to an inevitable crash.
4. Water fast – This is quite simple in theory. Just drink water. Except in extreme situations (like cancer or other terminal diagnoses), I tend to think the longest someone should go is 5 days. I’ve done it; some of my staff have done it. 5-day water fast will start the process of autophagy, or “self-consuming,” where the body begins to consume dead and damaged cells. Of course, a lot of people do it to lose weight, but the absolute best benefit is that this is one of the most powerful ways to reverse disease – and that includes things like cancer.
5. Lemon water fast – This is basically a water fast with a little flavor. The lemon does have some health benefits – Vitamin C, Vitamin A, etc. and, counterintuitively, it alkalinizes water, which has its own set of health benefits, particularly for fighting cancer. Just lemons though! Nothing else.
6. Salt water fast – I’ll lead with an important note on this one: MUST BE SEA SALT! Preferably Himalayan sea salt or Celtic sea salt. This gives you a dose of dozens of minerals, helps you feel a bit more full, adds some flavor, and is often considered a way to turn a fast around when it starts going bad. If you are on day 4 or 5 (or beyond) and start feeling terrible, adding a bit of sea salt is often the one small thing to get you through it.