You may have heard that Pastor Rick Warren of Saddleback Church in Orange County, California led his church on a mass diet and loss an unbelievable amount of weight. My pastor isn't doing that, but he is focusing on the main thing which is preaching Jesus Christ and exalting him. God accepts us the way we are physically and we do not have to lose weight to be spiritual.
We all know quite well that the Bible says that physical exercise is of some value, but spiritual exercise is of eternal value. It is paramount that we pray, witness, meditate, fellowship, study, worship, and read Scripture; but God has given us a body and we are to accept it. It is true that we were born with a body that had nothing wrong with it and what we have now is only a sign of our stewardship of this precious gift. Some of us do indeed take care of the gift better!
But we are not to exalt the body (i.e., extreme physical training for vanity sake, nor negligence due to our own fault when we know better. There is a happy medium; Jesus did not work out and I doubt he was overweight, but had a body not-to-be-ashamed-of, also. Remember that Adam was embarrassed that he was naked and feared God. The Bible talks about those who have forgotten how to blush and are a past shame; some of us should not be too proud of our physiques or figures. My pastor says that he is not ashamed of the body that God has given him.
However, the body we now have is really the body we gave ourselves by a lifetime of neglect or care. We should neither exalt nor show contempt for or mistreat the body. Ministers are examples to the flock and shouldn't draw too much attention to the issue. My pastor is very much overweight and it doesn't affect his ministries effectiveness--he says he's just had a lot of donuts and fellowship! Not everyone has the opportunity to get regular exercise, I might add. There is a reason why the Scriptures say that "your sin will find you out." Paul says the Cretans were "lazy gluttons" but that doesn't entail being fat, because it was known that people would eat and then vomit to eat more just for the pleasure of it.
My pastor says that he used to be skinny and as he aged his metabolism slowed down; I have noticed the same effect. There is no condemnation of fat people in the Bible I have noticed. Some people's sins are all too readily evident and others' are not as apparent--though they are still there. We are not to judge our brethren by their body types and be graceful in our attitudes. I would rather have a weakness for ice cream than for pornography which might be a secret sin that only God knows about.
We all want to feel accepted and must realize that there are more serious sins to worry about than the so-called deadly sin of gluttony (per Roman Catholic dogma, that is). There are many body types and one should not be biased than the one that is in fashion is the only acceptable one--a lot has to do with vanity and not health; in fact, being a little over your ideal weight adds years to your life, according to one scientific study I read. One can be thin and also guilty of gluttony and likewise obese and not a glutton, so it is wrong to judge by appearance.
Righteous people eat to their heart's content according to the Bible and as far as I know the New Testament doesn't command fasting or dieting for believers in this age, but as long as we are thankful we can eat away. We should never develop a guilt complex or let someone put a guilt trip on us. Personally, I don't believe in dieting (because most fail), but in making reforms to my eating habits step by step. Christians should say that they will stop trying and start trusting. Soli Deo Gloria!