Rather than just make a resolution to go to the gym or eat healthier, why don't you try to change the way you think? The first step to thinking positive and living a happier, healthier life is to love yourself. Now I'm not saying it in the sense that you look in the mirror 24/7 asking, 'who's the fairest of them all?'- I mean that you need to smile, and never doubt yourself.
A smile is a very attractive thing. It attracts others, who will also smile. You may be surprised at the difference in response and looks you get form others when you walk around with a smile on your face!
Have self respect by keeping your head held high in confidence. Don't let anybody put you down, they don't deserve to make you miserable. If there are people in your life who get in the way or come across negative, then you don't need them. Sure, you can't simply avoid certain people, but block their negativity out of your mind. A lot of people will judge you. Never judge others apart from yourself.
Remember to 'think happy to be happy'. Love your humour, do what you want to do for your life and deny any other negative person who says you can't do something. Respect your body to feel better.
It's a new year, and a new you!