I remember in the early to mid 70s fondue pot became the rage. Seems like everyone where I was living, was getting a fondue maker and having fondue.
Then the fad died out and of course people still use fondue pots but they seemed more of a fad to me?
What other food fads have their been?
Blackened redfish.
Kiwi seemed to be big in the late-'70s and early-'80s. Early-'90s everyone just had to eat dim sum. Sushi seemed to be extremely popular in the '80s. (In The Breakfast Club Molly Ringwood had it for lunch, probably because the director wanted everyone to know how trendy she was.) Of course sushi is still popular; but it was very trendy in the early-to-mid-'80s.
EDIT: Getting back to the pseudo-Cajun blackened redfish, this was so popular that as I recall the species was overfished. And in the mid-to-late-'90s Chilean sea bass (AKA Patagonian toothfish) was all the rage. Again, overfishing ensued.
Sundried tomatoes were everywhere in the world for a little while and then died back down to just being something good you could have if you wanted it instead of in everything. Ditto chipotle.
When I was a kid in the 80’s my mom served scallops a lot. It seemed like everybody’s mom did. They must have been popular for some reason.
Sea scallops or bay scallops?
If you count alcoholic drinks and wine, there have been many fads that died out. When I was a kid, everyone drank Old Fashioneds; now a bartender would have to go to his guide to know how to make one.* Rye whiskey has gone completely out of fashion; so much so that many liquor stores don’t stock it**, yet it was the best selling type of whiskey for years.
For wine, there was a big fad for Pouilly-Fuissé in the 70s and 80s, which ended about the time it got out that winemakers had used cheaper wines and labelled it as Pouilly-Fuissé and no one knew the difference. Beaujolais Nouveau also was a big fad that seems to have run its course.
*The recipe I remember: Muddle sugar in a little water, add Angostura bitters and ice. Pour a jigger of rye over it all and serve with a slice of orange.
**They usually sell Canadian whiskey or American whiskey in its place.
Ever see that “That '70s Show” where Kitty calls someone out for committing a “fon-don’t?” 
How 'bout aspic. A century ago or so, aspic was all the rage. Why people would want to eat food encased in something called “ass-pick,” I have no idea.
Sushi was trendy and exotic in the '80s, now it’s settled down as just another type of cuisine.
Pesto seemed to be in everything in the early '90s, but maybe that was just my dorm cafeteria.
Bacon seems to be all the rage for the last two years or so. Don’t get me wrong, I like bacon, but it’s really got to stop. I mean, really, this was in the Times yesterday. Bacon salt. Battered deep fried bacon. Bacon chocolate. Bacon wrapped bacon. C’mon. Enough with the bacon, already.
Seemed like northern Italian food, as opposed to red-sauce-and-checkered-tablecloths southern Italian food, was big in the late 1990s and early 2000s.
In WisConsin Old Fashions are ALWAYS made with Brandy unless you ask for whiskey. No cite though;)
Rye is very much coming back into fashion and has been for several years. It hasn’t hit mainstream consciousness yet, though. Ditto with absinthe.
Tall food was all the rage a while ago. In addition to the bacon fad, there is also the pork belly fad. And the “gourmet slider” fad. And molecular gastronomy/mixology.
Crockpottery, when it first hit in the early to mid 70’s was huge. Mexican took off in my area in the late 70’s 80’s… Gyro’s made a huge jump in the 70’s— for my Coney Island region it actually softened up and made the taco market entirely possible. First came the Gyro, then the Taco.
There was a huge microwave fad with accompanying cooking shows, largely implemented by Microwave manufacturers. They featured coookbooks with entirely microwaved meals from apppetizer, to soup, to salad, to entree and dessert entirely prepared with the “technology of the future”.
Now we all recognize that the microwave is only good for reheats and very specific jobs. Microwaved chicken breasts seemed to be a favorite of these early Microwavers… BLEGH!
Wasn’t the fad for “gourmet” pizza just over five years ago? I remember everybody going nuts for any kind of pizza that wasn’t your standard pizza restaurant fare.
And then there was the push for all fancy food to be shaped like it came out of a cat food can in short cylinders with some geometrically shaped garnish and a sauce that had a ten word long name drizzled around the edge of the plate.
I’m quite fond of the current “chocolate is good for you” fad.
Yeah, there’s been a slow resurgence in interest in rye since about 2003 or 2004. But it’s still under the radar in most places, and I still have difficulty finding it unless I go to a well-stocked liquor store.
The Breville sandwich maker was massive in the '70s. I think even now students tend to go through a phase of using them for every single meal and then one day the poor thing gets to go and sit at the back of the store cupboard and toasted cheese sandwiches drop off the household menu.
Crepes were all the rage back in the mid-70s or so. There was even a chain of crepe restaurants called The Magic Pan.
Ask for crepes now, and they look at you like you’ve got three noses or something.
People just have an abiding fascination with bacon. Like monkeys and ninjas, except you can eat it. Plus it’s the forbidden food, since it’s so bad for you.
If someone made lettuce-wrapped lettuce, no one would give a rat’s ass. 
Can you call something that is current a ‘fad’? I see molecular gastronomy as the evolution of food - it’s something that is and has been used in mass food production for a long time now (well a while anyway) and it seems logical to exploit these techniques in restaurant kitchens for maximum effect and to achieve new types of cuisine. I feel like it’s one of those situations I have had with my Dad about music where he’ll cite say ‘The Rolling Stones’ as an example of a band that plays ‘proper’ music and has lasted the distance and will say that anything new that I like ‘will never last’ but obviousley it’s easy to say that with hindsight. The fact that he has ‘The Prodigy’ on his iPod is enough retribution for me as I smugly pointed this out to him!
I think most ‘fads’ like say fusion for example go through an ‘all the rage’ stage before leaving behind the bits that people actually want. Fondue is not included in this theory for obvious reasons!
Not sure if this counts as a food fad. It seems to come and go.
Stuff you add to milk. The earliest I remember being advertised heavily was Bosko "chocolate " syrup. There is Ovaltine, Horlicks (jokes welcome), Nestle’s Quik, Hershey’s syrup etc.
I know these things are still around but it seems, based on my perception of the advertising, that they come in and out of fashion.