Whats the difference between burning off calories and eating less calories?

j2k43 Asked: Whats the difference between burning off calories and eating less calories?

What's the difference If I ate 1000 – 1200 calories a day and only did some light exercise for health (e.g. 20 mins brisk walking) or eating 1500 – 1700 calories a day and doing alot of exercise to burn 400+ calories.
Which is better for weight loss – and ASIDE from the health benefits of excerising I just want to know what difference it would make to loose weight if I would just not eat the calories I would burn in exercising?

Many thanks.. BEST ANSWER GIVEN