Tony Stark, AKA the Iron Man is one of the founders of the global protectors know as 'The Avengers'.
He often let's his heroic allies to live under the Stark mansion, a big house that caters every need they might have. So Captain America, Spider-man, Thor and even the Hulk had everything they needed to be on top of their game. From high tech exercise machines to a balanced diet, the Avengers were the mightiest heroes indeed.
But then, the bonbon incident happened.

Iron man was gifted by the French prime minister an endless supply of bonbon after he saved an important figure for the French parliament from a group of terrorists. Being a healthy man himself, Stark dropped the seemly endless stream of bonbon into his mansion. Where the other Avengers decided to try the candy because, well, why not?
They quickly became bonbon lovers, declaring it on public interviews it was their favorite food. Soon enough, the high influx of chocolate and sugar made them big, their muscles still remained through their new fat physiques.

The age of the Mightiest Heroes was gone, in it's place the Age of Bonbon has arrived.