Dear Erni,
Thanks very much for your letter. Sorry that I haven't written for so long but I was busy at work. I've so much to tell you that I don't know where to begin. Don't worry too much. I'll try to give you some advice on how to improve your eating habits and be fit.
First of all, if I were in your position I'd try not eat so much junk food and ready cooked meals. Moreover, you must cut down on sweets and fats. I think that you should remember about a proper diet consists of fish, meat, fruits, vegetables, still water and or two glasses of red wine a day. Your diet must be balanced. Crash diet is the first step to anorexia and it is very unhealthy way to get fit.
Secondly, you should do some exercises three or four times a week. I suggest swimming and joining a gym. Don't go everywhere by car, because your body needs plenty of physical activity. You will lose weight and soon you'll get in shape and feel better.
I hope that my advice helps. Let me know what happens. Give my best wishes to your family. I look forward to hearing from you.
Love,
Adam