Read the paragraph from the text.

the best way to burn off calories is by getting up and moving around! kicking a soccer ball, riding a bike, running races, swimming in a pool—all these activities are so much fun that nobody thinks of them as exercise. but they count toward the daily 60 minutes of exercise that the national institute of health recommends for all children! children and teens can work off calories, too. running errands, raking leaves, weeding the garden, taking out the trash—all these tasks combat the forces of obesity.

what does the underlined phrase combat the forces of obesity suggest in the text?

beat up obesity
get rid of obesity
win a race against obesity
fight a battle against obesity