food baby
n. A distended stomach caused by overeating.
Examples
2012
In this way, peplums also help those with less shapely body types by creating new Coke-bottle curves. Personally, I’m grateful that they mitigate signs of a "food baby," more commonly known as bloat.
—Amy Verner, “What body type works best for the peplum?,” The Globe and Mail, September 15, 2012
2011
All this follows Perry's comments at her Madison Square Garden concert on Nov. 16, where, according to multiple reports, she told the crowd she was bloated with a "food baby" from eating "New York City pizza."
—Frank Lovece, “Perry, Aguilera deny pregnancy rumors,” Newsday, November 22, 2011
2002 (earliest)
Vinny sticks out his stomach and taps it with his hands.
Vinny: I got a food baby working here.
I start laughing. It hurts my gut.
Vinny: Yeah, I'm eight months right now.
—“Guys get a dose of Pizzeria Uno's deep dish,” Contra Costa Times, April 24, 2002
Notes
I used to (and occasionally still do) marvel at the sheer variety and obscurity of associations, from the General Society of Mayflower Descendants to the National Grange of the Order of Patrons of Husbandry to the Puppeteers of America. Now I've come to believe that for almost any topic you can think of there's at the very least a web page and also likely a blog dedicated to that subject. Food babies are no exception, with The Food Baby blog ("Celebrating the Pursuit of Gluttonous Endeavors") a going concern since January, 2011.