Biblical fasting should not be considered a method for dieting, but a method for growing into deeper communion with God and being more in tune with His Spirit. The primary Biblical reason to fast is to take our eyes off of the things of the flesh and to open our eyes to the things of God.
Fasting is for stretching ourselves to enrich our dependence on Jesus by being in a weak state before Him, for He says “My grace is sufficient for you, for my power is made perfect in weakness” (2 Corinthians 12:9). Fasting is also a way to demonstrate to the Lord that we are serious about Him by fixing our eyes on Him alone.
The key to the different fasts that you find below is the simple act of participation. Do what you can to the point it is a sacrifice, but never to the point that you are in any way endangering your health. Fasting on a regular basis is actually good for your health as it will detox your system. Just do so in moderation and always pay attention to your body as you engage in fasting. Remember, you will be discomforted, but you should not be hurting.
You can engage in the Daniel Fast, which you can find multiple resources online that will give you guidance concerning this fast. It is a great fast for someone new to fasting. It allows you to eat regularly, but only certain foods, staying away from all things sweet. It is a very healthy way to eat even when not fasting.
This isn't necessarily Biblical in the true sense of the word. However, it does line up with Biblical principles in abstaining from things that would rob our time with God. This can be setting aside all social media, or all movies, or perhaps all the cat videos you watch on YouTube. Pick one or choose them all and step away for 30 days. You'll find in doing this your mind will be much clearer as it doesn't get bombarded by all of the vitriol from social media and it does keep one from wasting time.
Full Food Fast
This would be abstaining from food completely. However, as one would imagine this can rarely be sustained for 30 days, and we do not recommend this unless you are under the care of a professional nutritionist. What we are referring to here is to abstain from food for different periods of time throughout the 30 days. For instance: Fast a full day each Monday, or each Wednesday, or perhaps if you are used to fasting you could do two full days each week.
Modified Food Fast
This would be abstaining from certain foods. If sweets are your weakness, then set those aside. Perhaps it is pasta, or coffee, or tea, or soda, or pizza, or burgers. Whatever food you regularly indulge in, take 30 days to refrain from those foods. It's all about sacrifice. Keeping our focus on our relationship will choosing to refrain from the pleasures for a season.