It is not !

why is it best to include both exercise and calorie-reduction in a weight-loss plan? a. if you only cut back on calories, you’re more likely to regain the weight. b. you won’t be able to lower your weight without both exercise and calorie-reduction. c. dieting without exercising places an overwhelming amount of stress on the heart. d. you’ll be unable to fight off viral illnesses if you reduce calories but don’t exercise.