Wait until tomorrow. Wait until after vacation. Wait until you graduate or get that promotion. I spoke with a woman yesterday about weight loss and fitting into some new clothes for the summer. She told me her mom has been encouraging her to wait until things in her life "slow down" then focus on eating better and exercising.
Really?!? That is horrible advice! What if in the time she waited she develop heart disease? What if she rolls her ankle and exercise gets REALLY tough? The amount of calories she will have to eventually burn is not going to stop accumulating just because somewhere in the distant future there will be some glorious plan set in place.
Listen: DO IT NOW! Don't let ANYONE tell you to stay overweight. Its your body, and the only one you will EVER get. Take care of it...not tomorrow, NOW!
Now let's go and sweat it out!