I was explaining this to my daughter in quite simplified terms the other day- we evolved to taste sugar and enjoy it because finding a sweet edible plant meant we had a source of energy to help us hunt that day. Pretty useful if you’re a hunter-gatherer.
So we seek out sugar. Now we can get it whenever we want it, in much more massive quantities than we are supposed to be processing. Most of us are addicted. I’m not an exception.
Oh yeah - I’ve had to start watching my carbohydrate intake for health reasons and it’s amazing just how much of that stuff is in processed food: for example “American Style Onion Rings (frozen)” from Lidl is over 40% carbohydrates - so basically the 450g pack of it has 180g of sugars and the kind of stuff your digestive system will turn into sugars.
One would think it would be only starchy foods (like bread, pasta, rice and such) and cakes and sweets that have lots of it, but no, most processed food is loaded with carbohydrates, often already directly as sugars, probably because the cheapest ingredient to bulk it up is flour.
Mind you, lots of natural or lightly processed foods have quite a bit of it - for example natural yoghurt with nothing added has maybe 6% of carbohydrates (tough yoghurt with fruit is way worse, since the adding of fruit is generally mixing it with fruit jam which has a lot of sugar) and most fruits have quite a bit of sugar (for example, common varieties of apple have about 14% of sugar - so your run of the mill apple comes with 1 spoonful of sugar included - and some varieties have a lot more) which is why there’s this funny paradox that natural fruit juice has a lot more sugar in it than the same amount of Coca-Cola (since when you make the fruit juice you throw away the fiber and most of the protein leaving a much higher percentage of sugar than originally).
Generally, the kind of stuff that has almost no carbohydrates are veggies, like lettuce or broccoli.
Meat and cheese has no sugar/very low sugar too.
It’s great that you found a diet that helps with your health and works for you!
You probably know this anyway and most likely implied it, but I just want to stress that carbohydrates per se are not bad. Yes, eventually everything is being broken down to sugar, but you should not reduce carbohydrates to this function only. Oats are mostly carbohydrates, but they are whole grain with a lot of fiber and are a great source for iron (if not eaten with dairy). Their GI is in the 50s but you would have to take the whole dish into account, as rarely you’ll just sit there munching oats like a horse. Buckwheat and quinoa are often praised for their high protein content (and it’s true, they have like 10-12g of protein per 100g) but they still consist mostly of carbohydrates. A slow breakdown of complex carbohydrates gives you long term energy without raising blood sugars too much.