That is such an outdated opinion. It has been proven, for instance, that 5 year olds move around exactly as much as they did 30 years ago but are overweight. Why? Because of high sugar snacks 3 or 4 times a day and processed food with lots of sugar.
Don't buy into the BS. If you read my post you will see I didn't even up my exercise. In fact I have done less exercise (because of a damaged shoulder) but still lost weight because I cut down on SUGAR.