I find it ironic that many Christians who are obese also claim to be pro life. But how can you be pro life when you follow and promote a diet that leads to disease and death? By eating healthy, we choose life over death by avoiding obesity. "Oh, that you would choose life, so that you and your descendants might live" (Deuteronomy 30:19)!
I think that obesity is often justified by Christians who misinterpret the following Bible verses:
"What goes into someone’s mouth does not defile them, but what comes out of their mouth, that is what defiles them.” (words of Jesus) - Matthew 15:11
Myth: Here Jesus is clearly saying that diet has no effect on a Christian's health. Therefore a diet rich in deep-fried Twinkies, triple Whoppers, Diet Mountain Dew and even hallucinogenic mushrooms is perfectly healthy for Christians. In fact, the faithful can even expect perfect abs and a stunning physique when eating unhealthy.
The Truth: Here Jesus is saying that food is for our physical health, not our spiritual salvation. Taken in context, this comment by Jesus was a response to those enforcing ceremonial hand washing rituals. These "moral police" were more concerned with ritualistic ceremonies than a loving attitude. That being said, Jesus was not promoting a destructive, gluttonous diet filled with chemicals, preservatives and drugs. It is still wise to "eat for strength and not for drunkenness" (Ecclesiastes 10:17).
"They will pick up snakes with their hands; and when they drink deadly poison, it will not hurt them at all; they will place their hands on sick people, and they will get well.” - Mark 16:18
Myth: If Christians can drink poison and handle snakes, we can definitely handle McDonald's and Burger King every day. We also do not have to worry about cancer-causing chemicals such as sodium nitrate, benzoic acid, aspartame or MSG. In fact, chemicals found in cigarettes have been proven to cause cancer (Link) do not affect Christians at all.
The Truth: Some churches in the U.S. have taken up "snake handling" in their services. This often results in death (Link). Unfortunately, far more Christians have died early deaths because of unhealthy eating. Like the snake handlers, many Christians expect that God will simply make up for unhealthy living, even though Jesus said to never test God (Luke 4:12)! "They are headed for destruction. Their god is their appetite" (Philippians 3:19).
"Do not be with heavy drinkers of wine, Or with gluttonous eaters of meat; For the heavy drinker and the glutton will come to poverty, And drowsiness will clothe one with rags."
- Proberbs 23:20-21 (NASB)