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I think our best bet is to let our own bodies figure out what's good for us. The problem with that is that "food" these days includes many nutritive substances

I think our best bet is to let our own bodies figure out what's good for us. The problem with that is that "food" these days includes many nutritive substances which simply didn't exist in modern quantities during the evolutionary development of our appetites, most notably this abundance of fructose (HFCS, anyone?). The act of consuming food usually prompts one's body to produce insulin in order to assimilate the carbs in the food, and this insulin acts as an appetite suppressant. The problem is that fructose is so simple that no insulin needs be produced in order to assimilate it, so the appetite goes unsuppressed after the consumption of calorie-dense food, and the subject continues to feed. This leads to a positive feedback loop, because the stored calories require maintenance (heavier people must eat more to maintain their bodies, regardless of whether that weight comes from muscle or fat). This feedback loop causes all sorts of other problems, too. That's not even getting into the ancillary effects of the other stuff that we get from grain.

commandar 16y ago
>(HFCS, anyone?) I'm not a big fan of singling out HFCS because it misses the forest for the trees. Any refined carbohydrate is going to cause a strong insulin response. White bread is pretty awful for similar reasons, for example.
- presidentender 16y ago
  I do not disagree on any point.
- richcollins 16y ago
  There are considerations other than insulin response (other parts of liver metabolism): http://www.youtube.com/watch?v=dBnniua6-oM http://www.youtube.com/watch?v=dBnniua6-oM
kragen 16y ago
Your post is full of errors. Fructose was quite common in our ancestral diets, fructose is not any simpler than glucose, it's more difficult to assimilate than glucose, and heavier people do not generally eat more. There may be other errors I'm not even noticing, because I'm no expert in the field. Look it up.
- presidentender 16y ago
  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.

commandar 16y ago

>(HFCS, anyone?) I'm not a big fan of singling out HFCS because it misses the forest for the trees. Any refined carbohydrate is going to cause a strong insulin response. White bread is pretty awful for similar reasons, for example.

presidentender 16y ago
I do not disagree on any point.
richcollins 16y ago
There are considerations other than insulin response (other parts of liver metabolism): http://www.youtube.com/watch?v=dBnniua6-oM http://www.youtube.com/watch?v=dBnniua6-oM

kragen 16y ago

Your post is full of errors. Fructose was quite common in our ancestral diets, fructose is not any simpler than glucose, it's more difficult to assimilate than glucose, and heavier people do not generally eat more. There may be other errors I'm not even noticing, because I'm no expert in the field. Look it up.

presidentender 16y ago
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.