your just a kid which means your metabolism is high so lucky for you, you wont have to do much. First off you must know that only doing situps will not effect your stomach. Fat loss is associated on a whole body level. So if you want to lose the fat that is on your stomach then your best bet is to either start running frequently or start swimming frequently (the top two cardio fat burning exercises) and cut your eating down by a few hundred calories. this will then cause your whole body to lose fat which will then decrease the fat in your stomach.NOTE: it is impossible to just target fat loss in 1 specefic area. the body does not work like that.
At 13 you haven t hit your growth spurt yet, 120 at 5 4 is a normal, slim weight. Once puberty really gets going your waist will slim down and the weight will re-distribute itself as you get taller and change shape.It isn t a good idea to diet at 13 you need proper nutrition and most diets don t allow for the proper amount of nutrients you need to be healthy. Eat healthy foods every day and save the unhealthy ones for once in a while enjoy outdoor activities and your body will take care of itself :)Cheers!
i m thriteen and a little tuby around the edges if u likke u cna join weight watchers i have and so far i ahve lost 8 pounds over half a stone in just a few weeks.