Our physical health is a very important matter to focus on.
It is of little profit. Thank you to the apostle Paul for that insight. Paul certainly did not care too much about the condition of his health in comparison to the gospel. He would have been much healthier if he had not preached in several places. But it seems he was a glutton for punishment. After being beat and left for dead, he got up and walked back into the city, state of health ignoring.
Since our body is a temple of the Holy Spirit, we should do temple maintenance, keep it fit and free from injury and disease, as much as possible.
The point of that verse was for sin in the temple, not food.
We cannot effectively study and preach the Word, or serve others, or evangelize people, if we are sick, disabled, or weak from inactivity. The better off we are physically, the more we can do for God.
We are also going to die. It is not possible to preach, evangelize, or serve while we are dead. Should we focus on extending our life?
They did a study and determined that you extend your life roughly by the time you spend exercising. So unless you are on the treadmill while you’re preaching, you are not extending your life for the gospel, rather, for exercise. Since God gives health, and makes the food good for our bodies, I’ll trust Him to give me the health that I need when I need it to serve Him.
I think there are heavenly rewards for weight watching,
This is your opinion. That’s fine. But it doesn’t mean that it must certainly be true. If it were important for eternity, God would certainly mentioned the weight watchers crown. Since it is not mentioned, I doubt its existence.
which means honoring the body God gave us and controlling our appetites, improving our diet, and exercising.
Contemporary Christianity has pretty much ignored gluttony, to focus on condemning other types of cravings and addictions.
Contemporary Christianity has given itself over on the whole, to the satisfaction of the flesh. This is not limited to diet, and diet is the least of their problems, IMO.
But there are lots of articles that warn about pastor obesity and gluttony in general. This issue is not being brushed under the rug like it used to be.
There are lots of people who are offended by pastors and everyone who has internet may have a platform.
I Corinthians 6:19
What? Know ye not that your body is the temple of the Holy Ghost which is in you and which ye have from God, and that ye are not your own?
So as Christians, we do not defile the body with sin. It does not mean we should not defile the body with food.
Matthew 15:11
Not that which goeth into the mouth defileth a man; but that which cometh out of the mouth, this defileth a man.
I Corinthians 9:27
No, I discipline my body and make it my slave, so that after I have preached to others, I myself will not be disqualified.
But Paul has clearly taught Timothy that bringing his body into subjection is not specifically about bodily exercise. The condition of the body is not the goal of the Christian.
2 Peter 1:5-6
For this very reason, make every effort to add to your faith goodness; and to goodness, knowledge; 6 and to knowledge, self-control; and to self-control, perseverance; and to perseverance, godliness.
Self control reaches far deeper than appetite. It is the maintenance of the emotion. This is not strictly speaking of diet.
Proverbs 16:22
Better a patient person than a warrior, one with self-control than one who takes a city.
Principles to apply to diets? Sure. Dieting strictly speaking? No.
Proverbs 25:28
A man without self-control is like a city broken into and left without walls.
Temperance doesn’t exclude appetite, but I’m quite sure that the man referenced here was one who had lost his temper and not his diet plan. I don’t say they are unrelated. Just that diet would be a corollary to and not the focus of this text.
I don’t doubt your motives, but let’s keep the cart behind the horse.
1 Timothy 4:8
For
bodily exercise profiteth little: but godliness is profitable unto all things, having promise of the life that now is, and of that which is to come.
John 6:63
It is the spirit that quickeneth;
the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.
In all this, I am not advocating for gluttony. But it is not the focus.