Generally, half-marathon training programs start with the assumption that you can run 3-4 miles relatively easily, and are running three or four days a week. If you're there, a 12-week program should get you ready by July. If you're not, I agree with the previous poster that you might want to think about a shorter distance--a 10k would still be a challenging distance, but would be a bit more attainable.
As for whether the training is compatible with losing weight, it can be, but isn't necessarily. Running those distances is going to make you *hungry*! And once you get into some longer distances, you'll have to fuel your body during your runs, as well as before and after.
So, bottom line is that you might be able to lose weight while you're training, but I think losing a significant amount might be a stretch.
|92 Days until: Chicago Marathon