How many times have you heard someone complains that they started exercising to lose weight, but it didn't work at all? Why? The key to "losing weight" is to burn more energy and reduce body fat, but you can't increase the calories you expend simply by exercising longer. The amount of energy you burn depends on your weight and speed. To get more effective results with a walking routine, it is important to understand the mechanisms of how the body burns fat, and how much exercise is required to burn energy.
It is the balance of calorie intake and energy output. If the amount of energy you burn (via exercise, etc.) exceeds the amount of energy you eat, the body will use body fat to compensate for the discrepancy., and you will lose body fat.
On the other hand, if the amount of energy you eat exceeds the amount of energy you burn, then the excess energy will be stored as fat, even if you walk long hours.
1 kg (2.2 lbs) of body fat = 800 g (1.8 lbs) of fat + 200 g (0.4 lbs) of water
The amount of energy in 1 g (0.04 oz.) of fat: 9 calories/g
800 g (1.8 lbs) of fat = 800 g (1.8 lbs) x 9 calories/g = 7,200 calories
1 kg (2.2 lbs) of body fat = 7,200 calories
If you burn 7,200 more calories than you eat, you will lose 1 kilogram (2.2 pounds) of body fat.
Let's calculate the amount of exercise necessary to burn 1 kilogram (2.2 pounds) of body fat for a person who weighs 70 kilograms (154 pounds).
How much energy a 70-kilogram (154-pound) person burns when he/she walks for an hour at 6 km/hour (3.7 miles/hour) = Approx. 210 calories
How long it will take to burn 7,200 calories = 7,200 calories ÷ 210 calories/hour = Approx. 34 hours
Losing 1 kilogram (2.2 pounds) of body fat by walking seems a bit hard and you may think reducing caloric intake is much easier. However, losing weight just by eating less not only reduces body fat but also leads to loss of muscles and bones, easily resulting in rebound weight gain.
One kilogram reduction by walking, on the other hand, has additional merits. Your physical strength will improve and you can also expect lower blood pressure and declined blood sugar level. Therefore, the best way to lose weight is combining both walking and dieting.