Thinking requires energy, right? Some characters do more thinking than others. These characters will need to have a quick pick-me-up on hand, and most decide to eat some sweets. Perhaps the origin of this trope is the idea that showing a character eating sweets is a way to give the viewer clues as to their hyperactive nature, and it is harder to show the genius's mental hyperactivity on screen than another character's physical hyperactivity. Geniuses on TV also tend toward the socially immature and the eccentric, and showing them eating candy may be a clue to this. Even if a genius character isn't constantly bingeing on sweets, if they have a Trademark Favorite Food, it is likely to be sweet in flavor.
This is Truth in Television: the brain uses glucose as its primary source of energy and not getting enough is bad. Therefore, if you need to make your brains work a lot, you may need at least some sweet food...
Contrast Is It Something You Eat?, where a character reveals their love of food, and their idiocy. Compare Must Have Caffeine, which often overlaps. See also Cast from Calories and Donut Mess with a Cop.
- Professor Nova in Gunnm—flan pudding.
- Once Ikkaku bribed Urahara with a lollipop, Urahara was seeing happily eating it with no problems.
- Orihime Inoue is a Genius Ditz who loves doughnuts, according to a manga arc.
- Burn Up!'s Nanvel Candlestick: a world-renowned, award-winning inventor who demands Godiva chocolates and other sweets before she can work on anything. She never misses her three-o'clock snack, or her After-Dinner Dessert.
- In Classi9, Beethoven's love of sweets was unparalleled in Class S- until Ren came along. He is noticeably happier when there is pudding for dessert and cake has already distracted him from the matters at hand. Mozart also wakes him up with the smell of candy. The only time he didn't finish a piece of cake was after his fight with Wagner, because he felt like cake wasn't actually that good if you couldn't share it with friends.
- L and Mello from Death Note both ate sweets constantly. (In Mello's case, he was always ominously biting into some chocolate.)
- Nousou from Elfen Lied is seen regularly eating "Pocky".
- Spanner from Katekyō Hitman Reborn! loves lollipops and chain-eats them.
- Itachi Uchiha from Naruto plays with this trope. His favorite food is cabbage and onigiri (rice balls) with seaweed, but his hobby is visiting sweet shops.
- In New Game!, there's the genius character designer Kou. Despite Eagle Jump provides free coffee, she prefers getting her caffeine from soda (particularly Red Gull), and sees her pudding being stolen in Chapter 17/ Episode 8 as Serious Business.
- The Professor in Nichijou can always be expected to either be eating junk food of some kind, or trying to get someone to give her some. And as for the "genius" part, she's only eight, but she's capable of creating robots so advanced that it counts more like creating life itself.
- In Pokémon Adventures's Sinnoh arc, Professor Rowan is shown to have a fridgeful of sweets in his lab in Sandgem. In one early scene, he devours a cupful of sweets in less than 5 panels...and asks his lab assistant if he could also have the untouched serving.
- Yakumo Saitou from Psychic Detective Yakumo, though it differs between versions: in the Oda Suzuka manga, it's ice cream and muffins, and in the Miyako Ritsu manga, it's doughnuts.
- The Incredible Hercules' Amadeus Cho needs sugar to power his Hyper-Awareness. He prefers chocolate, to the point that he fills the Olympus Corp building with chocolate vending machines and instructs employees to report any shortages immediately.
- Chew takes this trope to new levels with characters who literally become geniuses when chowing down.
- The Chief of Doom Patrol is an expert on many topics, but gets very cranky if he doesn't have his chocolate.
- In the original cut of Ghostbusters (1984), Dr. Egon Spengler's sweet tooth was a little more obvious. Still, it can be noticeably observed throughout the final product. (Venkman rewarding him with a candy bar, munching on a box of Cheez-Its, and of course, the Twinkie.)
- In God of Gamblers, one of the titular genius gambler's distinctive traits is his love for chocolate (with a distinctive way of eating) which he keeps even after he got amnesia. The chocolate-eating habit is followed by his students in later movies, and, in one particular movie, an impostor (though he eats the wrong kind of candy and has a different way of eating).
- Peni in Spider-Man: Into the Spider-Verse is constantly shown snacking on candy while inside her Mini-Mecha. She's The Smart Guy and the resident techno-genius in the movie.
- Harry Potter:
- Dumbledore loves all sorts of candies, and the passwords for his office are always names of sweets. (Even something called Cockroach Clusters in one case.)
- He is not, however, a fan of Bertie Botts' Every-Flavored Beans, seeing as he always seems to have the misfortune of eating one of the nastily-flavored ones.
- Honor Harrington and her hot cocoa...
- This is one of the first things we learn about Laura in the H.I.V.E. Series:
Laura: These people seem to know that the way to a girl's heart is through her stomach.
- The title character in Swellhead by Kim Newman has a first-class brain and is never without a sweet snack to hand. His sweet consumption increases the more his evil alternate self takes over.
- The mentats in Dune use sapho juice to boost their already considerable mental abilities. It is described as cranberry-colored and highly energetic, so it is probably sweet. Baron Harkonnen's "twisted" Mentat Piter De Vries also eats spice (which tastes a bit like cinnamon) like candy. The Baron doesn't mind paying for Piter's extremely expensive addiction since it helps him control Piter.
- Much to the disgust of his partner Captain Hastings, Hercule Poirot preferred hot chocolate to tea and liqueurs to cocktails.
- Lord Auditor Georg Vorthys from Lois McMaster Bujold's Vorkosigan Saga is regarded as one of the Barrayaran Empire's top experts on Engineering Failure Analysis and has a Professor Emeritus post at Vorbarr Sultana University. He is very fond of desserts and makes regular trips to local bakeries to ensure that his supply of pastries does not run low. He also keeps a stash of cookies in his study.
- Nako of Genie Team G Jiken Note is a Ditzy Genius who has cake as her Trademark Favorite Food, and is also the reason why the series's Edible McGuffin Titles are all desserts.
- Discworld's Granny Weatherwax takes her tea with so much sugar that it's hard to move the spoon. Though part of this is because she's trying to ruin her complexion and get cavities; she thinks it's unsuitable for a witch to have clear skin and all her teeth.
- Hexarch Mikodez in The Machineries of Empire has an interestingly justified version - he abuses focus drugs which (like real amphetamines) suppress appetite and increase energy usage. Keeping his favorite high-calorie foods on hand at all times is part of how he stays passably healthy.
- Mentioned in Agent Carter - according to his butler Jarvis, eccentric playboy inventor Howard Stark's two major weaknesses are women and raspberry truffles.
- Brenda Leigh Johnson in The Closer has a thing for processed sugar products, as well as (unsuccessfully) trying to cut back. In one episode, her team gives her snack cakes to help with the case.
- Reid from Criminal Minds always seems to be munching on something unhealthy, especially when he's thinking. It gets to be a Running Gag—the team will be investigating a crime scene without any obvious food sources, and then Reid will pop up in the background, having located a vending machine or snagged a piece of leftover birthday cake.
- Doctor Who:
- The Doctor loves Jelly Babies. The Second Doctor was the first to mention them, but "would you like a jelly baby?" was the Fourth's Catch-Phrase. The Eighth, Eleventh and Twelfth Doctors and John Simm's Master have homaged it.
- The Doctor seems to also like ridiculously sweet tea:
- In one of the Big Finish Doctor Who audios, it's revealed that the Eighth Doctor habitually takes his tea with six sugars. It might be more accurate to say he takes his six sugars with a spot of tea, really...
- In the Fourth Doctor Doctor Who Magazine comic strips, it was revealed he took his tea with "just" eight sugars.
- In "Death in Heaven", we see the Twelfth Doctor dropping handfuls of sugar cubes into his teacup. It's unclear how many he takes as the camera cuts away without him seeming to have finished, but he's shown putting in at least seven.
- The Eleventh Doctor also seems fond of Jammy Dodgers.
- The Thirteenth Doctor has a thing for custard creams, so much so that her TARDIS console has a dispenser for them.
- Fringe: Walter Bishop loves his sweets: it's hinted at that he associates different types of dessert with different Fringe Sciences.
- Rory Gilmore from Gilmore Girls - a Big Eater and Go-Getter Girl, who spends most of her free time eating sweets and junk food and reading very thick books.
- Kamen Rider Ex-Aid: Hiiro Kagami, genius surgeon, is often seen eating sweets in his downtime. Running Gag involves him cutting the dessert with surgical precision. More rarely, someone steals a bite from him, leaving him speechless.
- The Leverage team tech-geek Hardison loves his orange soda and gummi frogs.
- In NCIS, both Abby and Gibbs seem to run on caffeine rather than sugar, though those Caf-Pow's are probably loaded with both.
- Parks and Recreation: Leslie Knope is a determined woman with brilliant political knowhow who puts whipped cream and sugar on basically everything, including pasta.
- Dr. K of Power Rangers RPM has sent the Rangers on shopping trips to the candy store. Her purchases are so large, the rangers must use a cart.
- Jarod from The Pretender runs on PEZ.
- On at least one occasion, he enjoyed a Monte Cristo, a ham and turkey sandwich dipped in egg batter and pan-fried like French toast, topped with powdered sugar and served with preserves or maple syrup.
- The entire point of the competitive dessert cooking show Sweet Genius.
- Android 21 of Dragon Ball Fighterz is a brilliant researcher for the Red Ribbon Army who loves scarfing down sweets. She also has the power to turn anyone she wants into sweets thanks to being injected with the cells of Majin Buu. As much as she hates the idea of eating people, she can't really control it.
- In Apollo Justice: Ace Attorney, Ema Skye conducts her forensic investigations while snarfing down her Snackoos.
- Kokonoe of BlazBlue is a Mad Scientist Deadpan Snarker who is usually drawn holding a lollipop. Her lab, when the player finally sees it, has a few sweets laying around, too.
- While not a "genius" in the traditional sense, the King's Quest guide says that Graham has a big sweet tooth.
- Caillou from Recettear: An Item Shop's Tale is a child wizard who keeps an eye out for promotional mud pies and used to go to church for the candy.
- Professor Rowan from Pokémon Diamond and Pearl, although it isn't obvious. You first find out that he has a thing for candy if you check out the refrigerator in his lab at the beginning of the game. (It's full of sweets.) Later, when after you beat the game, you can find him in the lower floor of the Veilstone City Department Store; if you speak to him, he complains about the Rage Candy Bars still being out of stock before he speaks to you.
- Maxima from The King of Fighters is a Genius Bruiser Cyborg who unabashedly admits his love for sweets. Justified, as he's also a Technopath.
- Lemres from Puyo Puyo is a particularly interesting case. He's a senior mage from a neighboring school whose fame as the Comet Warlock is publicized for attaining his status before he even graduated school. Lemres also has a great affinity for sweets, and has a nigh endless stock of them and freely shares them among his peers. The twist? According to him, candy and sweets fuel his magic power. In 20th anniversary, we get an episode of what happens if he abstains from having any sort of candy. It isn't pretty.
- According to Mega Man Battle Network, Child Prodigy Chaud takes his coffee with twelve sugars.
- Judging by the point pickups, the titular boy genius of Commander Keen has quite the sweet tooth, given that more than half of them are some sort of (usually alien) sweets.
- Beatrix from Battleborn is a scientist and has a thing for candy and chocolate based on the lores from Battleplans 30, 32, and 34.
- In The Legend of Zelda: Breath of the Wild, the library in Hyrule Castle contains a cookbook mentioning Zelda's favorite food was fruitcake, which she claimed helped her focus better on ancient technology research.
- Richard of Another Code is a chocoholic. His desk at work has a drawer filled with chocolate bars he snacks on.
- In The Secret World, youthful computer genius Harumi Nakahara is fueled by regular doses of sugary Bingo Cola. Also a case of Must Have Caffeine.
- Don't Starve has the gentleman scientist Wilson, who, when examining sweet foods, seems to like them a lot.
Wilson: [examining a sugar cookie] I'm going to eat forty. For science.
- American Dad! has one of the two CIA scientists who is more than willing to give away classified and potentially dangerous technology if offered Francine's brownies.
Francine: I brought brownies
Scientist #2: BROWNIES!!!
Scientist #1: ...He makes it hard to negotiate.
- The Marvelous Misadventures of Flapjack: in the episode "Skooled", Flapjack discovers that he can get candy (a task around which the entire show is centered) for correctly answering questions that the teacher asks. Despite never having been depicted in any sort of educational setting before then (he was raised by a whale) , Flapjack is able to answer the vast majority of the questions the teacher asks and it isn't long before he's so stuffed with candy he can't eat anymore and is unable to move. This does not deter him. After answering yet another question correctly he instructs the teacher to place the candy on his cheek, declaring that he'd get to it later.
- While immature, the Flash is one of the smartest characters in the DCAU Justice League universe, so much that he was once used as a computer to process information faster than otherwise possible, and he's always eating high sugar content food. It probably doesn't help that his powers take a lot of energy to run.
Flash: I can't think - I'm tired and hungry...
Detective: Maybe some coffee will help. How do you take it?
Flash: Cream and 37 sugars. [the detective starts, then looks at him incredulously] Really.
- The human brain largely runs on sugar (among other things). Long periods of intense concentration burn through this sugar at a faster rate, making minor sugar cravings common for people involved in such work.
- In professional settings, IT departments and nursing stations are infamous for being a good place to "dispose" of leftover baked goods or holiday candy. Definitely overlaps with Must Have Caffeine.
- Few would question that George Washington was a military genius, and, according to Alton Brown, he spent $200 on ice cream over the course of one summer, "and this was a time when $10 could buy you a really fast horse."
- In his autobiography, Stephen Fry spoke of a long enduring love for sweets, especially as a child.
- Andy Warhol was known for this. He visited pastry shops daily, sometimes buying an entire birthday cake for himself. He often refused more substantive meals, one time explaining to Tom Wolfe, "Oh, I only eat candy."
- According to an interview conducted by the BBC in the 1990s, if Stephen Hawking were stranded on a deserted island with a very limited selection of luxuries and amusements, one of them would be crème brûlée.
- According to an interview by the New York Times, Tarn Adams, unstoppable creator of Dwarf Fortress, hydrates primarily with soda, especially while he's working.
- Julia Medvienekov, the Wrench Wench from an untitled R&S production, is a mechanical genius who can frequently be seen eating chocolate.