The key to weight control is keeping energy intake (food) and energy output (physical activity) in balance. When you consume only as many calories as your body needs, your weight will normally remain constant. If you take in more calories than your body needs, you will put on extra fat. If you utilise more energy than you take in, you will burn extra fat.

How much exercise is needed to make a difference in your weight depends on the amount and type of activity, and on how much you eat. A medium-sized adult would have to walk a mile in a day for 30 days to burn up 3500 calories, which is equal to one pound of fat. Remember one thing, you don’t increase your food intake to reverse the effects of walking.

If you consume 100 calories a day more than your body needs, you will gain approx. 10 pounds in year. You could that weight off, or keep it off, by doing 20-30 minutes of moderate (limited) exercise daily. The combination of exercise and diet offers the most flexible and effective approach to control your weight.
Calories burned per hour in some activities
Bicycling 6 mph 240
Bicycling 12 mph 410
Jogging 5.5 mph 740
Jogging 7 mph 920
Jumping Rope 750
Running in pace 650
Running 10 mph 1280
Cross-country 700
Swimming 25 yards/min 275
Swimming 50 yards/min 500
Walking 2 mph 240
Walking 4 mph 440

Eat lots of fruits and vegetables
Fruits and vegetables contain more nutrients , relatively low in fat, and can fill you up without you having to consume a lot of calories.

5 Best exercises to try at home