Food and fashion changes late 1980s
 

In the 1970s and early 1980s American and British people were slim, they swam in speedos and played sport in short shorts. Then Coca Cola swapped out cane/beet sugar in it's drinks with fructose based corn syrup. This was intended as an ingredient cost saving but they discovered that where previously people were satisfied with one can or bottle of Coke they now demanded 2 or more drinks.
A food scientist studying this discovered that there was an optimal balance of sugars, fats and salt in food products that made the food irresistible but unsatisfying, you ate the meal but were left hungry, and went back for a second helping.
If you try to eat a tub of lard or a bag of sugar your body will say stop we're full, but if you make a delicious fat/sugar balanced cheesecake you'll keep eating it until it's gone and want more, especially if you swap out the sugar with corn syrup.
Everything you buy at fast food shops and all the processed foods you buy at the super markets have this scientific fat/corn syrup/salt ratio that allows you to keep eating and never feel full.
Suddenly in the late 1980s American and British people started putting on weight and wearing big shorts for swimming and sports to hide it. Rather admit that they were putting on weight they declared wearing speedos and short shorts was gay.
There was a sportswear fashion change because the food scientists altered everyone's food without them knowing so they'd eat more and still not be satisfied.

Back in those days, committing to wearing your Speedo to the beach or pool also inspired you (or at least me) to maintain a slim, trim body shape. Speedos worn in a recreational setting have always been a bit fashion-forward, guaranteed to attract some looks. If people are going to stare, give them something worth staring at! But Speedos never had a gay association that I was aware of until they became a popular costuming choice for participants in early Pride parades.

Back in the day, (here in the USA) your mid-afternoon Coca Cola was typically a small 8 ounce bottles, not some “Big Gulp” three times that size. Coke was a treat and sugar-rush, not what people drank to stay hydrated.

As Torchwatch described, when Coke replaced sugar with High Fructose Corn Syrup, the dynamic changed. HFCS is bad stuff which encourages drinkers to consume more sweetened beverages. I can’t claim I could tell the difference in taste, but I pretty much quit drinking sweetened soft drinks when my 20s “Adonis Bod” started turning into a 30s “Dad Bod”. I never missed it.

Eventually Mexican Coke developed an underground cult following because it still uses real sugar. You could only find it at Mercados catering to immigrants, a few Mexican restaurants, and strangely enough - at Home Depot. I found I liked the taste and actively hunted it down.

Then Costco started selling Mexican Coke by the case! Salvation for fans and a chink in Coca Cola’s ability to only provide customers with the corn syrup version. I don’t know if Costco sells Mexican coke nationwide, but if you want to try it, it’s generally along one side wall in 24 bottle plain cardboard cases.

We sometimes get European Coca Cola in small British shops, I have no idea where they get it from but guess it is cheaper, it tastes much the same.
There is a high fructose corn syrup plant at Tilbury Docks, Essex, England. The stuff is here too finding it's way into all kinds of processed foods, making kids too fat to play sport.