Being a good steward of your body is about being able to fulfill all that God has called you to do here on this earth, and honoring Him with the body He has given you.
It's about not allowing anything else to have control over you. Not food cravings, not emotional eating, not sugar. Nothing. God has given you a sound mind, and self control.
If negative thoughts and emotions are leading you to overeat in an attempt to feel better, then you may need to ask yourself if there's an idol in your life. The Holy Spirit is called The Comforter. God is referred to as The God of all comfort in 2 Corinthians. Where you run for comfort tells you where your trust lies. Do you trust God to comfort you?
There may be an area of your life you haven't fully surrendered to God and are trying to deal with on your own. It's time to lay it down at His feet and ask for His help. Food can't heal your soul, but Jesus can.
2 Corinthians 1:3-4
3 Blessed be the God and Father of our Lord Jesus Christ, the Father of mercies and God of all comfort,
4 who comforts us in all our tribulation, that we may be able to comfort those who are in any trouble, with the comfort with which we ourselves are comforted by God.
In Christ we are FREE. Not a slave to food. Not a slave to feelings. Are you being held captive by food or by your feelings? Jesus came to set the captives free. You may have relied on food to comfort you your whole life, but in Christ you are a new creation. It can be scary to let go of what you know, what's familiar and comfortable, but Jesus is trustworthy. You need to start seeing yourself as new. Allow God to reveal to you the woman He created you to be. That means removing all of the things that aren't you. God's offer is abundant life but He won't force you to accept it, nor will He force you to let go of your old ways. You have to choose the life you want. A life addicted to negative thinking, feeding your feelings, and being unhealthy, or a life of freedom and self control, where God is your comforter.
