Tolerance level or if harm is done? The two are not synonymous. We could tolerate poison even if harm is done. Indeed, I see a whole bunch of sick people walking around living their life in utter oblivion.

What we do elsewhere has little bearing on the toxic potential of carbohydrate. Carbohydrate remains toxic. We could exercise, eat "right", be happy and still die of heart disease because heart disease can't be prevented by anything we do. It can only be prevented by not ingesting the substance that is causing it.

Can we prevent snake bite (venom) poisoning with exercise or vitamins? No, we can only prevent it by not getting bitten by a snake.

The moderation argument fails when we eat only fat meat. We can eat as much as we want and still remain in perfect health. The moderation argument only works when we deal with toxic substances. In toxicology, they say the dose makes the poison. Indeed, a moderate dose of carbohydrate is probably harmless at first glance. Certain poisons accumulate. Take that dose for 20 years and it's just as toxic as if we ate the whole bottle all at once.

Have you ever wondered why a baby cried sometime when we feed it? Let me put it another way. Have you ever suffered from indigestion (cramps, bloat, flatulence, all painful even to an adult) after you ate some carbohydrate? What do you think it does to an infant then? So even then eating just a little bit of carbohydrate may be OK for an adult but it's that much more potent for an infant. The point is, the dose makes the poison.