If you are new to fasting it’s good to ease into it. If you have health conditions it’s also good to get advice from your physician.
In recent years, the definition of fasting has become broader. For example, people say they are fasting from tv, social media, listening to music, video games, or whatever. I am all for consecrating in these ways, but I think we should stick to the way people defined fasting for thousands of years. Fasting is essentially abstaining from food and/or water.
I don’t recommend fasting from water for more than a day. I think at three days without water you can really start getting into a danger zone. We can go without food, however, for about 40 days. Here are some suggestions, starting with the easiest. There’s no right way of doing these, so be creative and morph them into your own.
Partial fast
This might be “no meats, no sweets.” Or maybe eat breakfast, skip lunch and then eat dinner. You could eat a piece of toast for breakfast, an apple for lunch and then break your fast at dinner. You could fast during daylight (easier in the winter!).
Daniel fast
These fasts are inspired by Daniel in the Bible: "Test your servants for ten days; let us be given vegetables to eat and water to drink” (Daniel 1:12). If you are already a vegan or vegetarian, this is too easy, okay? But for people who eat lots of meat, sugary foods and carbs—this is hard! This is a very healthy fast, by the way, that could develop into a lifestyle. The Daniel fast can be done strictly with just vegetables and water or you can add beans, juice and even whole grains. This is the kind of fast you could do for several days or even weeks.
20 hour fast
One of the things about fasting is that it can interrupt good routines. If you exercise in the afternoon, then fasting breakfast and lunch is hard. You also might not be very pleasant if you have to work 9-5! This 20 hour fast might be best for you. Eat breakfast and lunch, and then fast until breakfast the next day. It’s 20 hours noon-8am. It’s important to have the evening of your fast free so you can devote yourself to prayer and the Word.
Juice fast
This is another common fast that eliminates all food and drink except a small amount of juice 2-3 times during each day. Some stick with lighter juices like apple or grape to not overload the digestive system. Others drink heavier smoothie-type juices to give them more energy. Speaking of energy, the juice fast amazingly brings you into a strange heightened energy after a while. I think that we don’t realize how much energy our bodies use to break down food on a normal day. One thing to note, however, is that the first day or two of fasting can be rough because your body is releasing toxins.
Just water
This one doesn’t need much explanation. No food. Just water. This can be very difficult, so I wouldn’t recommend starting with this. The fatigue is intense, and some people get headaches. I personally never do this and don’t plan on ever doing this—unless the Lord Himself descends from heaven and tells me to.
A few more things
If you are just starting out I would recommend the easier fasts and start with one day. It’s a little like exercise. You don’t jump into bench pressing 200 pounds on day one. Start small and work up. It’s best, in general, to fast when you have at least a good part of the day to spend in prayer. Prayer and fasting often go together in Scripture.
One last but very important thing to understand is that if you fast for more than a day you need to ease back into food so you don’t get sick. The longer the fast the slower you need to be easing back into your normal diet. Start with lighter foods and not too much. Don’t eat carbs right away and wait several days before eating meat. This requires self-control. Because after fasting several days—food tastes so delicious! And the temptation is great to eat too much too soon. I’ve failed in this many times and can testify that the stomach aches are terrible :/
There’s so much more to say about this, but hopefully this helps to get you going. I encourage you to do your own research before attempting a longer fast. Feel free to respond back to this email if you have a specific question. I’m happy to help if I can.
John Piper
Lastly, I want to let you know about another resource. John Piper is a pastor in the states and is one of the most influential Christian voices of our day. In addition to pastoring, John is the founder of a global ministry called Desiring God (I think he may have recently stepped out of pastoring and is now focusing on writing and preaching). Though Piper is older he has a huge following with the younger generation. Many of the younger Christian leaders like Matt Chandler, Francis Chan and David Platt, look up to him immensely. Piper has written countless books and articles and has preached thousands of sermons, all of which can be found at www.desiringgod.org. The reason I’m bringing up Piper today is because he has a meaty book on fasting and prayer called Hunger for God. I also came across this article on fasting by one of their writers on staff if you want some bonus material.