I should eat less while exercising to lose weight

Though you should certainly look to improve your diet when you embark on a fitness and diet programme, don't listen to that old adage that says less calories will help you reach your target quicker. You should aim to match your intake with the intensity of exercise you are doing - if you are burning thousands of calories a week then you need to eat plenty (of the right foods) to fuel your workouts.

In fact, you can pretty much eat as much as you like (within reason), so long as your diet is made up of healthy, balanced, natural ingredients and not foods that are high in saturated fat and sugar.