Most people don't "lose their chest" unless they diett rapidly and excessively, so if you are carrying extra weight in general by watching what you eat, doing some aerobic exercises and some wiehgt training can help. If it's an actual skin texture issue you might talk to your folks about seeing a dermatologist to find out if there are any surface creams or laser treatments - but if it has to do with "fat deposits" - you're going to have to tackle that first.
Finally, the same self-tanners creams/lotions that tan leg cellulite and help to camoflage the areas a bit - may also helf your torso.
Finally I'd get fast food and processed food out of your diet since it certainly doesn't help your waistline, your skin and may be having an impact.