Eat less + exercise. The most reliable way to lose weight is by eating fewer calories than your body burns up during a day. Look at the foods that you eat in between meals, the sweet drinks, even juices and you'll find a lot of extra calories that you probably can do without. Then try to be more active. Start walking 10 minutes a day. Increase till you're walking 30 minutes. When you're there, push for 2 miles/day.
Eat less. Losing weight is conceptually simple. Ingest fewer calories than you burn up. All diets are based on this principal. You can burn calories faster with an exercise program. Enlist the aid of your family doctor and a nutritionist and an exercise specialist.