Question: "Is gluttony a sin? What does the Bible say about overeating?"
Answer: Gluttony seems to be a sin that Christians like to ignore. We are often quick to label smoking and drinking as sins, but for some reason gluttony is accepted or at least tolerated. Many of the arguments used against smoking and drinking, such as health and addiction, apply equally to overeating. Many believers would not even consider having a glass of wine or smoking a cigarette but have no qualms about gorging themselves at the dinner table. This should not be!
Proverbs 23:20-21 warns us, “Do not join those who drink too much wine or gorge themselves on meat, for drunkards and gluttons become poor, and drowsiness clothes them in rags.” Proverbs 28:7 declares, “He who keeps the law is a discerning son, but a companion of gluttons disgraces his father.” Proverbs 23:2 proclaims, “Put a knife to your throat if you are given to gluttony.”
Physical appetites are an analogy of our ability to control ourselves. If we are unable to control our eating habits, we are probably also unable to control other habits, such as those of the mind (lust, covetousness, anger) and unable to keep our mouths from gossip or strife. We are not to let our appetites control us, but we are to have control over our appetites. (See Deuteronomy 21:20, Proverbs 23:2, 2 Peter 1:5-7, 2 Timothy 3:1-9, and 2 Corinthians 10:5.) The ability to say “no” to anything in excess—self-control—is one of the fruits of the Spirit common to all believers (Galatians 5:22).
God has blessed us by filling the earth with foods that are delicious, nutritious, and pleasurable. We should honor God's creation by enjoying these foods and by eating them in appropriate quantities. God calls us to control our appetites, rather than allowing them to control us.