Sadly, exercise doesn't take off very much weight.
It is good for your general fitness and can decrease insulin resistance in your muscles but to properly lose weight you have to eat less calories.
If you get shin splints running then you need to rest your legs - but are you sure that they are shin splints?
Has a sports expert of a doctor/nurse diagnosed them?
Anyway, if your legs can't take the pounding at the moment, have you considered cycling?
It is much lower impact and will also improve your leg fitness.
You may find that after cycling has toned up your legs then you can run O.K.
If you don't want to cycle, then try walking instead of running - a program for running training for non-runners usually starts out with walking interspersed by a little gentle jogging to get your legs into the swing with out damaging yourself by trying to do too much too soon.
If you are very active during the day and your overall fitness is good, then perhaps you just need to cut back on those meals during your break.
Exercise in the fresh air can build an appetite and most of the builders I know are at least 'chunky'.
Best of luck with your exercise.
Cheers
LGC