"Rice and grains" and the like contain only starch.

The physiological effects of starch, which is composed only of glucose, are very different from the effects of sugar, half of which is fructose.

Until about two hundred years ago, all the sources of concentrated sugar, i.e. honey, cane sugar, dried fruits and boiled fruit juice were very expensive in comparison with other kinds of food and very few people could afford to eat them more frequently than a few times per year, at more important holidays.

Almost nobody could eat food with high content of sugar every day, like most people do now.

The availability of sugar or glucose-fructose mixtures that are cheaper than almost any other kind of food, so they are now added to reduce the cost of industrially-processed food, is a very recent phenomenon.

Hunter-gatherer tribes such as the Hadza get a significant fraction of their calories from honey and other simple sugars. They don't seem worse off for it.

https://doi.org/10.1038/ncomms4654

They also are so active that all the ingested fructose must be oxidized immediately, instead of being converted by the liver into fat, as it happens in the more sedentary modern people.

Historically, they would not had that many vegetables available to eat daily either. Likewise, meat was quite expensive. In quite a lot of places, beans and such vegetable proteins were not available all that much on regular basis. Majority of contemporary diets, including keto, vegan, vegetarian were impossible or expensive. Raising bees for honey is not a new thing by any standard.

Another thing is that historically, malnutrition was a thing, not just something rare. The people would be getting serious diseases or be dying because of this or that missing in the food, there were whole epidemics of diseases that basically do not exist anymore.

The context here is fructose, you're mixing it up with glucose. Both technically sugars, but very different effects. People have had access to lactose for a long time too, but fructose is the issue.

The context here is "fat vs sugar". To which reaction was "they were eating fruits not sugar".

The context here is that major food group that was pretty significant source of calories - complex carbohydrates was skipped creating dichotomy between sugar and fat.

Fresh fruits have only a low content of sugar.

The recommendations that I have seen are that up to around 50 g of sugar per day (25 g of fructose) should be fine.

Most fresh fruits have about 10% of sugar, so you need to eat more than a pound or a half of kg to reach levels of sugar intake that could be unhealthy.

Only a few fruits have more sugar, above 15%, e.g. grapes, fresh figs or fresh dates. Even with those you must eat an amount over what would satiate most people, in order to get too much sugar.

On the other hand, if you eat one chocolate (many of which contain 60% or more sugar) or a few candies you are likely to have already exceeded an acceptable daily intake.

Like, who cares. My argument was about potatoes, rice, bread, ... Sure if you eat full chocolate every day and are nor teenager or weightlifter you probably eat too much of it.

And still, that doew not mean you nmed to cut complex carbohydrates and go keto ... especially if argument is how people 300 years ago eate. It was not keto.

Again, sugar is a shorthand for fructose. Whenever this comes up someone muddies the water by saying that glucose is a sugar too but that isn't what is being talked about.

I never seen sugar used as shorthand for fructose. It would mean majority of candies dont have sugar in them - they dont have simple fructos

And it is not used that way by people who push keto and low carbohydrates diets on HN.

And again, it renders fat vs sugar dichotomy meaningless.

I don't know what you mean by 'simple fructose'. You're the only one who has said that. Candy usually has high fructose corn syrup which is about 60% fructose and 40% sucrose.