What is fasting in the Bible, and how do Christians fast today?

In the Bible, fasting usually means going without food for a set time in order to seek God. It shows up in both the Old and New Testaments, in many different situations. Jesus fasted, and he spoke about fasting as something his followers would do.

Fasting in the Bible

People in the Bible fasted for different reasons. A few examples:

• In grief. When Nehemiah heard that the wall of Jerusalem was broken down, he sat down and wept. He mourned for many days, fasting and praying (Nehemiah 1:3-4).
• In danger. Esther planned to go to the king, even though it was against the law. First she asked the Jews in Shushan to fast for her for three days. She and her maids would fast too (Esther 4:16).
• With a partial fast. While Daniel mourned for three weeks, he ate no pleasant food and had no meat or wine (Daniel 10:2-3).
• As part of worship. Anna, a prophetess who was very old, served God in the temple night and day with fasting and prayer (Luke 2:36-37).
• Before big decisions. The church in Antioch was ministering to the Lord and fasting when the Holy Spirit told them to separate Barnabas and Saul for the work he had called them to. They fasted and prayed again before sending them off (Acts 13:2-3). Paul and Barnabas also prayed and fasted when they appointed elders (Acts 14:23).

Jesus fasted as well. He was led into the wilderness, and after forty days and nights of fasting he was hungry. That is when he was tested (Matthew 4:1-2).

If you are praying about a big decision of your own, read How do I know what God is calling me to do?

What Jesus taught

In Matthew 6, Jesus teaches about giving and prayer before he gets to fasting. Each time, he says “when you” (Matthew 6:2-6).

“Moreover, when you fast, do not be like the hypocrites, with a sad countenance.” (Matthew 6:16, NKJV)

He told his listeners to anoint their heads and wash their faces, so that only their Father would know they were fasting. He sees in secret, and he will reward them (Matthew 6:17-18).

When people asked why his disciples did not fast, Jesus said the time would come when the bridegroom would be taken from them. Then they would fast (Matthew 9:14-15).

What fasting is for

Going without food makes room. The time and attention you would spend on eating can go to prayer.

The Bible is also clear that fasting means little if the rest of your life ignores God. In Isaiah 58, God’s people complain that he has not noticed their fasting. God answers that on their fast days they exploit their labourers, and that they fast for strife and debate (Isaiah 58:3-4). The fast he has chosen includes letting the oppressed go free and sharing bread with the hungry (Isaiah 58:6-7).

Through the prophet Joel, God calls his people to come back to him with all their heart, with fasting and weeping. He wants a change of heart more than an outward show (Joel 2:12-13).

How to fast today

Here are some ideas if you are starting out:

1. Know why you are fasting. Write down what you are praying about.
2. Start small. Skip one meal and spend that time praying or reading. Our guide on how to start reading the Bible can help you use the time well.
3. Try a partial fast. Like Daniel, you could give up certain foods for a set period.
4. Keep it quiet. Jesus said your fasting is for your Father, who sees in secret.
5. Decide when it ends. Set the length before you begin.

A long fast

In episode 7 of Tea Time With Thandie, When the Wilderness Gets Loud, Thandie mentions that she had fasted for over two months. The episode looks at Matthew 4, where Jesus is tested in the wilderness after his own fast.

In Matthew 4, Jesus’s fast was followed by testing. If you feel flat or far from God after a fast, read When God feels silent.

Look after your health

Fasting affects your body. Get advice before you start if your health could be affected.

• Diabetes. Diabetes UK says fasting can be dangerous if you have diabetes, and advises talking to your diabetes team before you decide to fast (Diabetes UK).
• Prescribed medicine. NHS advice for people fasting during Ramadan says to keep taking prescribed medicine as normal, and to check with your GP if you have concerns about doses or timing (Northumbria Healthcare NHS Foundation Trust).
• Pregnancy or breastfeeding. The pregnancy charity Tommy’s advises talking to your midwife or doctor if you are thinking of fasting (Tommy’s).
• Eating disorders. The British Dietetic Association warns that fasting can trigger a relapse for someone with an eating disorder (BDA). The charity Beat runs a free helpline. In England the number is 0808 801 0677. Check its opening hours on the Beat website.

If you start to feel unwell while fasting, stop and get medical advice. The same NHS advice suggests 111 online, a pharmacy, calling 111 or your GP practice.

For more honest conversations about faith, listen to Tea Time With Thandie.