Hi Kevin and welcome, Like you I have always struggled with my weight, and although I lost it all at 20 I put it back on again by 25, now I'm 28 and I really regret having missed out on so much.
When it comes to food you have to remember you are the one in charge of what you eat, don't let the food control you or like me you will really regret it later on.
For me it was noodles and chocolate. A big bowl of noodles, chicken legs and some vegetables to make me feel like I'm eating healthier.. then chocolate as a snack. 3 months into my diet I have not had any noodles and not a single bit of chocolate, and I don't even miss either of them.
The fact that you're posting here shows you want to make a change, and you will if you really want to.
Exercising alone is not for everyone, maybe joining a gym would be good for you, or having a like minded friend to exercise with, then you can push each other on.
sit-ups are OK if you want to train your abs, and you will burn a little off that way but not much, the more muscle groups you train at the same time the more fat you burn, so you can do aerobic exercises and resistance training.
For me I like to do weight training such as squats, bench press, flat dumbbell fly, overhead press. Training as many muscle groups as I can at the same time. But as I'm on a diet I wont be gaining much bulk, I need an excess of calories each day for that.
For aerobic training I started off with just long walks and moved onto walking up and down hills, now I go up and down some steep steps for 40 minutes each night.
what ever you decide to do, keep it simple, get a workout you like and stick to it, push yourself with what ever exercise you do and the more you push the better the results, all the best!!
