I'd say sugars aren't bad for you. Sugar in fruit, even the not as sweet ones around a long time ago, was good fuel for us. It was rare. We developed a taste for it cuz it was rare and valuable so we are born to eat it when we find it. We have too much of it around us now.

I'm not saying to drink your tea with sugar but I think the amounts that would have been around a long time ago in whatever goodies we could scrounge would have fueled us well.

Sugar is a trap that fruits evolved to get animals to eat their seeds and then, with help from the poisons in the seeds, pass them through undigested and fertilized. It's a pretty awesome trap too considering that the toxic sugar does not induce satiety so as not to inhibit animals from obsessively stuffing their faces with it.

Not everything we eat is somehow because of our benefit. We're just smart enough (dumb enough) to get the toxic bait ourselves now and turn it into pleasure inducing super toxic bait. This is not a new concept for humans. We're like moths who have learned to harness fire.

Remember we have to take the environment of evolutionary adaptation into consideration. The form of sugar back then was berries, which are good for you. The modern discordance between what we are adapted to and the crazy stuff we do with our technology is what produces problems.

same reasons diamonds are a girls best friend....they are rare therefore treasured....sugar was rare evolutionary speaking. It grew seasonally and only year round around the equator.

Sugars act on the pleasure centers of the brain, like lots of other things and activities. Things that taste sweet in nature abound. As a kid, I learned to pull out the red flowers of clover plants and suck on the white tips where the sweet nectar is. As mentioned, obviously fruit can be very sweet, and also provide a lot of nutrients. Many veggies and even grasses are sweet to the taste. The "bad" part comes in when it's packed into everything and we become emotionally adapted to expect it in nearly everything, and then more recently in history, to where the sugars are refined so that they no longer behave in the body the way natural sugars do.

Aside from all of that, I think humans in developed nations are so far removed from survival and appreciating food due to its abundance (vs. the paucity at times that would have plagued our ancestors and does still plague our relative in the third wold nations) that we seek to indulge ("let them eat cake") because we can. Self control seems to have gone out the window in the last few decades, perhaps because it's not necessary for basic survival (note: "survival" in this context does not equal optimum health, feeling good and energetic, avoiding disease, etc, but simply being alive and functioning to some degree).

Add to all of that the fact that Big Agribiz wants to make money by promoting foods derived from the easiest grown and processed crops ----> corn into HFCs, wheat into everything, sell, sell, sell. Get us hooked and sell, sell, sell.

I'd go with a combination of the 'toxic trap' hypothesis, and the idea that sugar in nature is somewhat rare (and valuable - having full glycogen stores might very well enhance your ability to survive - by enabling you to do high intensity activities longer, such as hunting or escaping hunt), also fruits hold valuable nutrition (phytochemicals), so in the end fruits are food that the plant offers as a trade off for you helping it with it pollination. Whether it is a good trade off, or you are being tricked (poison trap) depends on the situation - the fruit, your metabolic situation and so on...

Also as a side node - the highest concentration of sugar, occurring in the natural world, and hunter gatherers favorite food number one - is Honey - which the bees obviously don't intend for us to consume, but which again is their pay (are they also being tricked?) by flowers to help them pollinate. The sugar in honey is popular among native people, probably because it is a super dense source of calories and replenishes glycogen, as wells a provide some other nutrition, and off course tastes awesome.

There are no poisonous sweet fruits