I have two sides to my feelings on this ad:
The other half of me wants to scream and yell at whomever THOUGHT THIS WAS A GOOD IDEA -- honestly by tugging-at-the-childhood-fears of the fat kid who heard this little song you added to the edit as a kid in elementary school? I am too young to have known about it, but I am that fat kid who failed the Presidential Physical Fitness Test. The "kids" that would recognize it are not the "kids" shown in the ad -- clearly. They are the next generation maybe.
Because what the hell is CHICKEN FAT?