Walter Denton on Our Miss Brooks. It usually manifests when he arrives at Mrs. Davis' house to drive Miss Brooks to school. He usually asks for, and eats, a Mountain of Food. This is always after having breakfast at home. As a teenaged boy, it probably comes with the territory.
Both Alex and Max from Happy Endings-its more notable in Alex's case because she's tiny and petite, and Max is depicted as more of a fat guy, despite having a basically average build. Still, when the petite 5'3 girl and the 5'10 guy are eating roughly the same amount of food, you know which one is playing the trope straighter.
A more modest though still unrealistic form of this ability is displayed by the waifish title characters of Gilmore Girls. Lampshaded when Luke comes over to Lorelai's house and looks in the refrigerator:
Luke: There's nothing in here but ice cream, candy bars, cookie dough, frosting— why are you not 450 pounds?
Lorelai: I know. Scientists call it the Lorelai paradox.
Joey Tribbiani from Friends. In one episode he volunteers to eat a whole Thanksgiving turkey, which doesn't mean he'll stop eating until then. (He calls it "warming up.") Another episode involving Phoebe's birthday dinner at a nice restaurant. Over the course of the episode, everyone, including Phoebe, leaves for other activities... except Joey. He's bummed at first, but lights up when all of the already ordered entrees arrive.
Joey: Dinner for six for one? (to waiters) You guys are about to see something real special... (he even eats the birthday cake afterwards) Joey: This is the best birthday ever!
He even eats - and enjoys - Rachel's infamous Shepherd's Trifle. He likes it so much that he sneaks around and eats the four uneaten portions that the others couldn't manage.
Joey: What's not to like? Custard? Good. Jam? Good. Meat? Good.
Dean Winchester of Supernatural eats constantly and spends most of his life sitting in a car, but still manages to look as toned as Jensen Ackles. All the "Dean eats constantly" jokes have been getting slightly jarring recently because Jensen Ackles looks like he's lost even more weight while Jared Padalecki (the one who's never seen to be eating) looks like he could bench-press him easily.
Leviathans takes this Up to Eleven when it's found out that they not only want to turn humans into livestock, they also want to kill anything else that might eat humans because there's only seven billion of us.
Fred of Angel is shown to eat a lot, despite being played by the waifishly thin Amy Acker. Lampshaded when, after a breakfast with Gunn, he says "Where do you put it all in that little tiny body?"
Another Korean Drama, 49 Days, has the thin Ji Hyun's stomach constantly growling whenever anybody mentions food. She also never turns down an offer of dinner.
Best Friends Whenever: Despite having a slim built and impressive athletic poweress, Cyd often displays love of food such as eating two lunches at once, always being hungry and eating halfway of chocolate from the garbage in "A Time To Jump And Jam".
Upon being invited for dinner at the Summers home, Faith is ravenously shoveling food down her throat and sneaking food off of Buffy's plate. Slayers in general are big eaters, Faith was just the first one to demonstrate it onscreen. Apparently, Slaying makes them "Hungry and Horny". Given Faith's living situation, it's quite possible she hadn't eaten for a while.
Buffy is apparently more sneaky about it.
Giles: All I know is, the fate of the entire world may well depend on... (sees donut box) did you eat all the jellies? Buffy: ... Did you want a jelly? Giles: I always have jelly; I'm always the one who says "Let's have some jellies in the mix"! Willow: We're sorry.... Buffy had three!
Heroes: Sylar is often seen snacking on something and clearly enjoyed eating an entire pie by himself. A video montage was collected of how many times he's been seen onscreen with food. He also makes frequent references to food and his desire for abilities is often described as a "hunger".
Samantha Marquez on Las Vegas is Front Of House's secret weapon during a hot dog eating contest against Back of House, despite Vanessa Marcil looking like she's never even touched a hot dog. Sam brags that her nickname used to be "Hummingbird", since she could eat twice her body weight.
An episode of Stargate SG-1 has the team's metabolism boosted by alien devices. The sneak off base and go for steak. Jack orders three steaks, and calls the waitress back with the "That's just for me" line while Carter and Daniel order the same. Then Carter adds And a Diet Coke. (When she gets the look, she explains that she likes the taste.)
From Stargate Atlantis, Dr. McKay is a big eater. He's not terribly discriminating, either — the only thing he doesn't like about airline food is they won't give him seconds. Except for any food including citrus, which he's allergic to.
The Androgums in "The Two Doctors" had huge appetites and would eat just about anything, including their own species.
In The End Of Time, The Master has been revived, but he's...not quite right. One of many unsettling effects include an intense, intense hunger. At a food stall, he orders everything they have in stock, and devours it all at high speed. In another scene, he eats an entire roasted chicken within a minute.
Chuck Noblet in Strangers with Candy is constantly eating at his desk, which turns out to be foreshadowing for "Feather in the Storm" when we find out he's bulimic.
There is an ongoing gag about how much Liz Lemon loves to eat, especially junk food (perhaps because her life is so hectic she never has time for proper meals.) Liz also gets pretty violent when someone steals her food.
Jack also shows some stress-eating tendencies of his own, such as in the first season episode "The Baby Show," where Liz remarks to Josh that "Jack Donaghy is gonna kill me and then he’s gonna kill you and then he’s gonna fold us up in a pizza and eat us.”"
D.I. Peter Carlisle in the BBC miniseries Blackpool is almost always eating, unless he's unhappy.
Jayne Cobb seems to spend more time eating or looking for food than another crew member of Firefly, moreso in the feature film.
"He's always eating! That's why they're so poor."
He has, on at least one occasion, called dibs on food abandoned by other crew members.
"Hey, free soup!"
At least part of it is because the average food for space farers is protein paste. As soon as any fresh food becomes available, even Inara becomes a Big Eater. Also, Jayne is massively muscular and is called upon not only to fight, but to move heavy objects and the like, and is constantly training, so he's losing/using a lot of energy.
Steve from Full House. One episode even shows him grabbing food from the Tanner residence before his dinner date because he wants to "warm up".
Latka Gravas is sometimes featured as this: Louie once asked the cabbies to take one chocolate from a box. Then Latka began to eat the entire box except for one chocolate. Louie then lampshaded this:
Louie: I said "take one". Latka: I thought you said "leave one".
Latka's wife Simka also appears to be this, as Latka himself remarks that one thing he loves about her is that she eats like a pig.
In the pilot of CBS's The Flash (1990), Barry Allen, much like his nephew in the comics, was explained to burn calories at a tremendous rate and was thereafter shown constantly inhaling food. In one episode he's shown stopping a crime at a banquet, and when the people he saved look around after he speeds out, they notice the turkey (Not cold cuts, the entire bird) is gone. The next scene shows The Flash finishing off a drumstick.
The Flash (2014) features this trait for Barry as well. In fact, it's a physiological necessity: He metabolizes food so fast that he'll collapse from hypoglycemia unless he consumes massive amounts of food at a time. Cisco Ramon at one point estimates that Barry would need to eat over six-hundred tacos daily to meet his food intake needs. In the crossover with Supergirl, Barry states he needs to eat 10,000 calories.
Kara Danvers from Supergirl also loves food and regularly consumes tons of it. Not being human, her body doesn't react the same way to it, and she stays thin and fit. This comes in handy, when Barry, who needs to consume tons of food to maintain his Super Speed, wants to find a nice takeout place. Kara is happy to help.
Brent and Lacey from Corner Gas. Brent even eats a bowl of pierogies in under 5 seconds, and says it isn't his best time. He only took so long because Lacey fed him a big plate of chili cheese dogs before their eat-off in an attempt to fill him up.
Julius Nicholson from The Thick of It: "A man cannot live on Jaffa Cakes alone — I've tried".
Miley Stewart's father Robbie Ray is very often seen at home raiding the fridge, and his expanding waistline is a Running Gag on the show.
Carly Corinthos Jax of General Hospital. Despite never being portrayed by an actress above a size four, Carly's love of junk — especially pizza and chips — is legend. In 2009, junk food nearly becomes its own character when Carly's perilous pregnancy forces her to go on an all health-food diet. References are made on a near daily basis about how her husband and sons are keeping her from her beloved crap, and when Carly finally goes into premature labor, it's while on a clandestine trip to score an order of fries from her favorite bar.
Alex Russo of Wizards of Waverly Place. Her parents run a sub shop, and she often takes customer's orders for herself, or finishes off their leftovers. She sometimes takes the dispensers from the tables in the shop and empties them directly into her mouth. She keeps an assortment of inappropriate food in her locker at school, including pizza, popcorn, milkshakes, whipped cream and maraschino cherries.
The West Wing: Ainsley Hayes — the trope namer for Blonde Republican Sex Kitten — likes to finish her statements with, "Are you going to finish that?" and a common Running Gag is her hunting for something to eat. That said, she doesn't eat as much as most people on this page.
Trick: Ueda Jiro, physics professor, ate a year's worth of rice in one day, then later in the episode (chronologically) ate a pot of rice that had been meant for over a dozen people.
On The Beverly Hillbillies, Jethro Bodine would eat any unguarded food (or what appeared to be food) in the kitchen. His typical breakfast was a large mixing bowl filled with Kellogg's corn flakes and milk.
Mike Stivic from All in the Family, much to the chagrin of Archie, whose fridge Mike is always raiding.
In an early episode, Will takes a distressed Finn to an all-you-can-eat restaurant where they can talk. One shot shows their plates side-by-side: Will's contains a moderate, healthy amount of meat and salad/vegetables, while Finn's, which is the same size, is piled high and overflowing with everything you can think of. It continues to be implied in later episodes that Finn is a Big Eater: Brittany points out that "You have sloppy joes for lunch every day and think you can get away with it," and being ravenous between meals is the reason he ends up dedicating a week of his life to a Grilled Cheesus. Which he eventually eats. When it is at least a week old and has travelled back and forth between home and school, unrefrigerated, who knows how many times...
We later also find out that Coach Beiste eats a whole rotisserie chicken at every meal - until she's burdened with the musical, student council elections, football etc, discovers that Breadstix delivers, and starts carbo-loading on enormous bowls of pasta. A damn' good trencherwoman, Shannon Beiste.
Pat Sajak and Vanna White really go out of their way to sample local cuisine whenever Wheel of Fortune tapes on location. This was even referenced on a Clip Show (the 4,000th nighttime episode), which showed footage of Pat and Vanna indulging while "Eat It" played.
In an episode of M*A*S*H Klinger tried to become a Big Eater when he learned that obesity could get you kicked out of the army. Like many of his hair-brained schemes, Reality Ensues after eight large salamis gives him a really bad tummy ache.
Tommy was a Big Eater in one episode temporarily when the Monster of the Week, a Villainous Glutton, miniaturized itself and tricked Tommy into swallowing him; the idea was to act as a Trojan Horse to get to the Command Center, but it gave Tommy an uncontrollable appetite.
Lindsay Messer on CSI NY sometimes. In one episode, Danny asks if he can get her something to eat while she's doing paperwork, and she asks for a whole list of stuff. Danny gets an Oh, Crap! look and she has to assure him she isn't pregnant again.
Veronica Mars: Wallace Fennel, as he's a basketball player who needs the energy:
Wallace: The day of the back-to-school athletics banquet there were spirit boxes in our lockers. There weren't any brownies in there, but there were cookies.
Veronica: Did you eat one?
Wallace: I ate six.
Veronica: That's my Wallace.
Leslie Knope in Parks and Recreation definitely qualifies. Leslie eats massive amount of junk food, especially waffles, sugar and whipped cream, while managing to stay pretty slender.
Ron Swanson, her boss. Who often frequents JJ's diner with her, and is probe to ordering every dish at once, or ALL their eggs and ALL their bacon.
What boy on House of Anubis doesn't fall under this trope? It's most notable with Mick, Alfie and Eddie.
Even the actors acknowledged Mick's tendency to eat- his eating scenes are written in the script. Apparently the actor isn't much better, either.
With Alfie, not only does he always eat- he eats a lot. And it's rather messy, too. He's the one who once almost ditched Sibuna to eat Trudy's cookies instead while the students were under lock down and not allowed to eat anything Victor didn't allow them to.
Eddie is nearly as bad as Alfie is, though at least he can separate his duties from lunch time.
On Ned's Declassified School Survival Guide, there's a student known as "One-Bite" who can, as his nickname implies, consume any food item in a single bite, making him The Dreaded during lunch time. Once he actually left behind a small scrap of Ned's sandwich, but that was because he only took a "tiny" bite.
Kel from Kenan & Kel. In one episode, Kenan leaves Kel alone with the Thanksgiving turkey. He comes back a few minutes later and is horrified to find Kel has reduced it to bone.
Sam from Nowhere Boys. In the first episode he's so hungry he eats cream for itchy crotch by accident.
Kousuke Nitoh on Kamen Rider Wizard. He practically eats anything and usually uses mayonnaise to top his food, even on food that wouldn't make sense with it. His Phantom is an even bigger eater, consuming Phantoms whole. In fact, he requires Nitoh to feed him Phantoms, lest he eats him next.
Emma Swan on Once Upon a Time is always seen snacking on something. Justified in her Dark and Troubled Past as a foster child and runaway, she never could predict when her next meal would be, so she ate whatever she could get her hands on.
Emma: Where I come from, if you don’t eat fast, the big kids would swipe things off your plate.
Agent James Aubrey from Bones. If a scene has him sitting down, it is almost guaranteed that he will be sitting in front of a spread of Styrofoam takeout containers (which he will invariably refuse to share with Booth). One episode had the team investigating the death of a TV food critic, and Aubrey acted like one of his heroes had been slain. He even had to resist eating week-old food out of the guy's van.
NCIS's Ellie Bishop, to the sheer amazement of her coworkers. Tony even suggests that the reason they've never met her husband is because "you had him with some fava beans and a nice Chianti". When he does finally meet the guy, his first question is "How the hell does she eat like that?"
Similarly, NCIS: New Orleans's Meredith Brody, frequently seen wolfing down the delicious New Orleans food.
The Dukes of Hazzard features one of the more famous comedic archetypes: Boss J. D. Hogg. He's not only a Fat, Sweaty Southerner in a White Suit, but the show frequently demonstrates his big appetite, either by displaying a big meal he's about to eat or by showing him reaching for something else to eat.
Lost's Hurley is a compulsive eater and extremely overweight. Since the DHARMA products were discovered in season 2, he has been seen hoarding food and gorging himself at times. This was needed to Hand Wave the common question of why Hurley was not losing any weight despite being stranded on an island, but also added to the character's Back Story.
Friends: Monica Gellar was shown to be like this as a child, most likely related to her numerous compulsive tendencies. Her parents were even once shown asking her to eat excess Thanksgiving leftovers when they ran out of space in the fridge and the show presented this as a typical request.
One episode of CSI dealt with a man whose brain did not process "full" signals from his stomach, and therefore constantly felt hungry. If he was not physically restrained, he would eat every morsel of food in the house and continue foraging for more. (He died of a ruptured stomach in the wake of an eating contest.)
Bertram the lazy butler from Jessie is massively overweight and is always napping and rarely doing his job. He even has trouble reaching for the remote because it's "too far". He also orders many food and invades the fridge many times.
Ron: Just give me all the bacon and eggs you have... Wait, wait. I worry what you just heard was, "Give me a lot of bacon and eggs." What I said was, "Give me all the bacon and eggs you have." Do you understand?
According to the book Pawnee: The Greatest Town in America, four times a week Ron eats a meal at JJ's Diner called the "Four Horse-Meals of the Egg-Pork-alypse", which consists of a 12-egg scramble, bacon, ham, sausage, hash browns, chicken-fried steak, and a huge stack of buttermilk pancakes.
He can also eat a party platter meant to serve 12 people in four minutes.
Wizards of Waverly Place: Jerry is very lazy and likes to eat food out of the garbage. He even rigged the Family Wizard Robe to have an unlimited supply of hoagies in the left sleeve.
Bob Duncan from Good Luck Charlie has a huge weight gain from his obsessive eating always digging on food for whatever the reason and is made fun of by his family (mostly Gabe) for this. He also can be manipulated with Food as Bribe. However, over the course of the series, Bob starts to lose weight and gains a Heroic Build.
Don Wilson on The Jack Benny Program, although not nearly to the extent of how he was characterized in the radio version.
Pretty much everyone on The Sopranos, bordering on Food Porn. They're eating in every episode: big, heavy, Italian meals of pasta and meat and sauces and alcohol.
Smul from Studio100's Kabouter Plop series is the biggest gnome and is always seen eating sweets and cookies. But what he really loves eating is tarts and cake.
More "moderately overweight" rather than "fat", but Law & Order: UK's DS Ronnie Brooks is one, enough for it to be a Running Gag—his partner and supervisor tease him relentlessly and anyone who wants a favor knows to bring him a snack. There's a legitimate explanation for this—he's a recovering alcoholic and has replaced his craving for liquor with one for sugar.
Ñoño from El Chavo del ocho, obviously as a joke that he’s fat. He generally competes with Chavo as the most glutton character. In his case is for the exact opposite reason; Chavo is glutton because he’s poor and is always hungry, Ñoño is glutton because he is rich.
Twin Peaks: Fit and slender Agent Cooper is always gorging himself on large quantities of unhealthy food. He orders a very large and unhealthy breakfast at the Great White North in an early scene. He matches the local cops in eating large quantities of donuts. Most notably he belts down the local diner's pies at every opportunity. The sheriff marvels that he must have the metabolism of a hummingbird.