Every one of these comes with a reward that seems nowhere near the punishment you're putting yourself through if you complete the mission.  Some will waive the bill of roughly $50, others will give you a t-shirt that lets you advertise the fact that gluttony is your favorite of the Seven Deadly Sins, many will take a picture of you afterwards and post it on their Wall of Fame (or shame?), and there are a few that give you... wait for it... more food.

Bon appetit.

The Fat Shack Challenge (Fort Collins)

Three 1 1/2-pound sandwiches with fries, which you have to eat in 30 minutes.  Two people have done this so far.  https://www.fatshack.com/

 

Sports Station American Grill's Atomic Wing Challenge (Loveland)

One pound of wings in 10 minutes with nothing to drink.  Oh, and no napkins, either.  http://www.bestcoloradosportsbar.com/

 

Beau Jo's Legendary 14'er Challenge (Fort Collins, Denver, Arvada, Idaho Springs, Evergreen, Boulder, and Steamboat Springs)  

Two people have one hour to eat the Grand Sicilian – 14 pounds of hamburger, sausage, pepperoni, green peppers, onions, and mushrooms all covered with cheese atop a thick, 16” crust.  This one comes with a $100 cash.  https://www.beaujos.com/

 

Pho 95's Pho-King Challenge (Denver and Centennial)

2 pounds of noodles, 2 pounds of meat, 200 ounces of broth, and a separate plate of vegetables.  (No time requirement??)  http://www.pho95noodlehouse.com/pho-king-challenge

 

Jack and Grill's 7-Pound Breakfast Burrito Challenge (Denver, Littleton, and Westminster)

5 pounds of grilled potatoes, a dozen eggs, ½ pound of ham, ½ pound of cheese, onions, and your choice of chili - and all you get is your picture on the wall.  (The burrito alone is worth it, right??)  http://www.jackngrill.com/

 

De Antonio's Colossal Carnivore Challenge (Winter Park)

45 minutes to devour an 18” stuffed pizza with sausage, pepperoni, ham, meatballs, and mozzarella.  No one has done this yet.  https://www.facebook.com/DeAntoniosPizza/

 

Rib City's Beast of the East  (Fruita, Glenwood Springs, Grand Junction, and Rifle)

1 pound of baby back ribs, 2 pounds of chicken, ½ pound of sliced beef, ½ pound of sliced pork, ½ pound of baked beans, ½ pound of cole slaw, ½ pound of fries, 1 baked potato, and a few slices of Texas toast. A total of 6 pounds!  (For the vegetarian who can't take it anymore?)  https://ribcity.com/

 

The West End Tavern's Wing King Challenge (Boulder)

50 wings in 30 minutes.  https://www.thewestendtavern.com/

 

King Chef Diner's New Mexico Stomper  (Colorado Springs)

You get an hour to down this 5 pound burger served open-faced with green chili, cheese, lettuce, tomato, and a side of fries.  (Oh, that must be so fun on that 59th minute!)  http://www.kingschefdiner.com/