Always remember that it is more important to have a quality workout than to have a long one. However, you should try to progressively increase the time spend working out from twenty minutes to an hour. Besides working out, you also need a healthy diet if you want to lose weight.
Raspberry Keytones are all natural rasberry supplements that speed up metabolism and fat burn, it was even recommended on the Dr. Oz show. I'm also taking Hydroxycut Proclinical, both you take 30 min before a meal and it suppresses your appetite and speeds metabolism; it ultimaley has made a big difference as well. I started 5'7" 145lbs and now dropped 8 lbs in a few weeks with a 1500 cal diet and mild exercise. The supplements are very low risk and what I needed to get those extra stubborn pounds. To further your weight loss, drink only water or green tea (boosts metabolism and suppresses hunger, etc). 0 calories too. Go all natural and stop going out to eat. Small changes likes choosing wheat/whole grain instead of white help a TON. Do a little bit of weights, google excersices for your problem areas. And do lots and lots of flat-ground cardio to burn the fat (biggest help). After excercise refuel with protein to burn even more calories and help sustain muscle health. Do all that and you can't go wrong. It only takes dedication and remember it takes time. Anything is possible.