But at this point it is remarkable to me that news sources are still not acknowledging a difference between fructose and glucose. According to these sources, a donut and a bagel are equivalent (modulo fat content) because the carbs of both will break down into "sugar" in the blood.
It has long been obvious to me that an orange and a bagel have very different effects on satiety. Eating sugar makes me HUNGRY, fast. Eating an equivalent amount of calories in the form of a bagel tides me over for a while. Could these both be just "sugar"? Is it just about "glycemic index," i.e. how fast they break down into "sugar"?
A friend showed me this video at Thanksgiving: "Sugar: The Bitter Truth." (It has apparently gone viral.) Here, an M.D. explains that fructose must be converted into glucose by the liver before it can be used, and that conversion process is sloppy and generates toxic by-products. What I had previously read was that this liver bottleneck was good because it slowed down the absorption of fructose and thus lowered its glycemic index. It turns out that this is naive: fructose actually causes metabolic damage, which is similar to the damage from chronic alcohol use.
So the assumption that the evils of fructose implicate all carbs is unfortunate, because it leads people to try to follow low-carb and high-meat diets, which I personally find unpleasant, which are likely to be as high or higher in calories, and which may even be risky due to some research showing that animal-based proteins (particularly milk protein) may catalyze cancer and foster autoimmune problems.
The crowning touch to me is when articles like these justify the demonizing of all carbs by citing the fact that agriculture is a recent human invention, so humans must not have had access to significant amounts of carbohydrate before very recently, in evolutionary terms. This is an odd fantasy. What about indigenous cultures that forage for starchy tubers and wild legumes? But in fairness, it took me years to figure this out. When I was around 20 I tried a raw vegan diet, and I realized that after I'd eliminated fruit (the sugar made me too hungry, and the acid made my teeth hurt) and after I'd eliminated nuts (large quantities led to indigestion, and it would have been too hard to find enough to live on in the wild) I eventually realized that all I had left to eat were tubers. And those were good raw but I couldn't get enough calories without cooking them to release the starch. Yet the light bulb *still* didn't go in until about a month ago, when I wrote a Toastmasters speech about my dietary adventures. You know how they say that humans needed a boost of calories to evolve a larger brain, and that boost of calories probably came in the form of becoming a hunter and starting to eat meat? Well here's an alternate theory. Maybe those proto-humans discovered fire and learned to cook their tubers. Presto, lots more calories! It has been established already that fire was discovered before agriculture. That makes agriculture a natural progression in looking for more things to cook.
But people like meat - all primates like meat - and so we enjoy having a plausible justification for eating more of it. And so when it becomes obvious that drinking lots of soda causes health problems, it is easy to wield a broad brush and blame all carbohydrates. And so people following a "paleo" diet and trying to stick to their evolutionary blueprint decide it's better to eat a piece of fruit than a potato. Boy, do they wind up having it backwards.