To start the year off on a positive note, avoid resolutions in the spirit of self-dislike. Rather than focusing on weight loss, why not resolve to improve your relationship with food, and while you're at it, your relationship with your body? This will help you now and will last way beyond the crash-diet/gym-heavy January norm.
Other ideas for resolutions:
Develop a healthier relationship with exercise
Accept yourself as is, while still leaving room for change and growth