Small Pink Blob wrote:
Lol at leafy greens boosting energy. Some of the worst "foods" in existence.
Care to explain? I tried looking at the science behind this when I first saw it, but most of it went over my head.
Basically, since plants generally don't employ mechanical defenses, they have evolved a whole host of interspecies warfare chemicals to prevent themselves from being eaten. These compounds do everything from block nutrient absorption (tannins, phytic acid, protease inhibitors, etc.) to stimulate autoimmune diseases (lectins).
The leafy greens that civilized humans eat, of course, have been selectively bred by agriculture for reduced antinutrient content, so they're not as bad as eating wild plant fodder. But they're still there, and they still have significant effects.
In small amounts, these compounds can be used medicinally- hence one of my dietary maxims: Plants are excellent medicines, but terrible foods. There is nothing wrong at all with drinking teas, taking herbal supplements, eating small amounts of herbs, etc.- but eating these plants in large quantities, as foods, is counterproductive and unhealthy.
Believe it or not, fiber actually generally stunts nutrient absorption, and it even scrapes up your intestines in a real mechanical sense (causing mucous release, which also prevents nutrient absorption by causing food material to slide right through your intestines). This is actually one reason why medical professionals advise the consumption of copious amounts of fiber: they assume everyone eats carbohydrates, and the best way to ration the absorption of carbohydrates into the bloodstream (and thus prevent massive insulin surges) is to consume them with indigestible carbohydrates (i.e., fibers), which block their intestinal absorption. But this blocks nutrients in general- it makes more sense to simply reduce one's carbohydrate consumption, and keep nutrient absorption high.
Note that, in the case of the action of many antinutrients, this blockage of nutrient absorption is irrelevant. Protease inhibitors, for example, block the action of enzymes in your stomach that break down proteins- they don't have to enter your bloodstream to exert their negative digestive effects.
3: And finally, per unit weight, they are just really low in nutrients compared to nutrient-dense animal foods. In nutrition and health classes and resources, plant foods like leafy greens are considered nutrient-dense, and animal foods are considered nutrient-poor, but this is on a per calorie basis (animal foods simply have a lot more calories per unit weight, and leafy greens have practically nothing in this regard). On a per weight basis plant foods don't hold a candle to animal foods. Also, plant foods lack compounds like triglycerides and fat-soluble vitamins that facilitate mineral absorption and utilization.
Relatedly, fruits are crap because they have so much sugar in them (and domesticated fruits are worse than wild fruits, because they have been bred for higher sugar content). Nuts are borderline okay, but they have a lot of antinutrients, as well (after all, the seeds must be protected from being digested by animals, in order to germinate and produce a new plant). Supposedly there are special soaking methods to remove antinutrients from nuts, but I haven't bothered with any of that.
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