3 ms·

I have not asserted that fructose did not exist in the past, that it is simpler than glucose, or that it is more difficult to assimilate than glucose. I do ass

I have not asserted that fructose did not exist in the past, that it is simpler than glucose, or that it is more difficult to assimilate than glucose. I do assert that the average modern human's diet contains much more fructose than his great-grandfather's. I do not believe this is debated anywhere, although I will accept evidence to the contrary. I am not sure what you mean when you say that heavier people do not generally eat more. Base metabolic requirements increase with body mass; as such, if a heavier person does not eat more, he will cease to be a heavier person.

kragen 16y ago
You said, "The problem is that fructose is so simple that no insulin needs be produced in order to assimilate it." But insulin needs to be produced to assimilate glucose. Your subordinate clause could only be true if fructose were simpler than glucose. Also, your subordinate clause could only be true if fructose were less difficult to assimilate than glucose. It's not. It's more difficult. It has to be converted into glucose in order to be metabolized. Dates and figs, staple foods throughout human history, are over 20% fructose by weight. Many fruits and vegetables derive more than half their calories from fructose and, in a few cases, fructans. Throughout the evolutionary development of our diets, fruits and vegetables supplied the majority of our calories. So saying fructose "simply didn't exist in modern quantities during the evolutionary development of our appetites" is false. Fructose could indeed be a major cause of health problems, but not because it was a small component of our ancestral diets. It might be a slightly larger component today, but I suspect it's actually considerably less because of the higher protein and fat content of modern diets. Metabolic rate per kilogram varies widely among people, and within the same person over time. Epidemiological studies have shown that, at least in the US, heavier people have a much lower metabolic rate per kilogram, to the point that heavier people generally tend to eat less. There's lots of speculation on why this is — do they have thyroid disorders? are their bodies conditioned by widespread yo-yo dieting? do they get less exercise? — but I'm not aware of a consensus yet.

kragen 16y ago

You said, "The problem is that fructose is so simple that no insulin needs be produced in order to assimilate it." But insulin needs to be produced to assimilate glucose. Your subordinate clause could only be true if fructose were simpler than glucose. Also, your subordinate clause could only be true if fructose were less difficult to assimilate than glucose. It's not. It's more difficult. It has to be converted into glucose in order to be metabolized. Dates and figs, staple foods throughout human history, are over 20% fructose by weight. Many fruits and vegetables derive more than half their calories from fructose and, in a few cases, fructans. Throughout the evolutionary development of our diets, fruits and vegetables supplied the majority of our calories. So saying fructose "simply didn't exist in modern quantities during the evolutionary development of our appetites" is false. Fructose could indeed be a major cause of health problems, but not because it was a small component of our ancestral diets. It might be a slightly larger component today, but I suspect it's actually considerably less because of the higher protein and fat content of modern diets. Metabolic rate per kilogram varies widely among people, and within the same person over time. Epidemiological studies have shown that, at least in the US, heavier people have a much lower metabolic rate per kilogram, to the point that heavier people generally tend to eat less. There's lots of speculation on why this is — do they have thyroid disorders? are their bodies conditioned by widespread yo-yo dieting? do they get less exercise? — but I'm not aware of a consensus yet.