“Beer belly” is one of several slang names for abdominal fat. Male beer drinkers often develop “beer barrel” bellies—also called “beer gut.” The term “beer belly” dates from the late 19th century.
Wikipedia: Abdominal obesity
Abdominal obesity, colloquially known as belly fat or clinically as central obesity, is the accumulation of visceral fat resulting in an increase in waist size. There is a strong correlation between central obesity and cardiovascular disease.
Visceral fat, also known as organ fat or intra-abdominal fat, is located inside the peritoneal cavity, packed in between internal organs and torso, as opposed to subcutaneous fat which is found underneath the skin, and intramuscular fat which is found interspersed in skeletal muscle. Visceral fat is composed of several adipose depots including mesenteric, epididymal white adipose tissue (EWAT) and perirenal depots. An excess of visceral fat is known as central obesity, the “pot belly” or “beer belly” effect, in which the abdomen protrudes excessively. This body type is also known as “apple shaped”, as opposed to “pear” shape, in which fat is deposited on the hips and buttocks.
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Several colloquial terms used to refer to central obesity, and to people who have it, refer to beer drinking. However, there is little scientific evidence that beer drinkers are more prone to abdominal obesity, despite it being known colloquially as “beer belly”, “beer gut”, or “beer pot”. One of the few studies conducted on the subject did not find that beer drinkers are more prone to abdominal obesity than nondrinkers or drinkers of wine or spirits. “Love handles” is a colloquial term for a layer of fat that is deposited around a person’s midsection, especially visible on the sides over the abdominal external oblique muscle.
“Muffin top” is a pejorative term used for a person whose midsection spills over the waistline of his or her trousers in a manner that resembles the top of a muffin spilling over its baking pan.
Merriam-Webster Dictionary
Main Entry: beer belly
Function: noun
Date: 1951
: potbelly
— beer–bel·lied \ˈbir-ˌbe-lēd\ adjective
(Oxford English Dictionary)
beer belly slang, (a) a protruding stomach or paunch caused by drinking large quantities of beer; (b) transf., one who has such a stomach.
1942 BERREY & VAN DEN BARK Amer. Thes. Slang § 121/7 Drunkard’s paunch, beer barrel, *-belly, -muscle or tumor.
1969 Rolling Stone 28 June 26/1 Woods pauses to tuck his shirt between a beer belly and a silver belt buckle.
1972 G. BEINE Land of Coyote 26 They described Pa as a beer-belly and said Ma was unfriendly.
1986 D. GETHIN Dane’s Testament xviii. 120 He wore a ridiculously tight shirt that accentuated his beer belly.
2 May 1876, Indianapolis (IN) Sentinel, Pg. 1:
...Mr. Thomas with a beer belly, to the high office of councilman, and help reduce the tax on tea and coffee.
11 March 1896, Omaha (NE) World Herald, pg. 8:
He says he is six feet in height, weights 200 pounds and has no “beer belly.”
Google Books
It Can’t Happen Here: a novel
By Sinclair Lewis
Edition: revised
Garden City, NY: Doubleday, Doran & Company, Inc.
1935
Pg. 205:
The Rabbi was unable even to answer, but little Dr. Schmidt the had a doughnut mustache, a beer belly, and black button boots with soles half-an-inch thick said, “Macgoblin, I suppose I may talk frank with an old student, there not being any reporters or louispeakers arount.”
Showbiz Spy
Johnny Depp Wants to Grow a Beer Belly
May 22 2009. Posted by Adam
Johnny Depp can’t wait to retire from Hollywood — so he can grow a beer belly.
The Pirates of the Caribbean actor — who started out as one of Freddy Krueger’s first victims in the 1984 film A Nightmare On Elm Street — is being remarkably modest in his plans for old age.
“I just want to become a traditional old man with a beer belly,” says Depp, who will soon be seen in gangster thriller Public Enemies. “I’d like to be sitting on the veranda of our place in France, just staring out over the lawns.”