ZTG1992

Im a 17 year old male and was looking for some help for a diet. I'm about 240 lbs and 5'10.

I was looking at a program "fitday" and was hoping to lose around 40 lbs in a few months and it suggested I eat consume around 800-1000 calories a day, not considering calories lost through exercise.

I was planning on riding a stationary bike for atleast an hour a day, and hopefully finding a gym that allows minors to work out there.

Is a calorie diet a good idea or might there be a better way? I considered limiting carb intake as well.