I must admit that I am biased toward a vegan diet for a long list of reasons (though definitely not in any way relating to the so-called "
animal rights" nonsense). The greatest reason for me is portion control: animal products are healthy only in very small quantities, while my appetite usually wants ten times more. It is easier for me to cut out all animal products entirely, so after a while the cravings go away. Another bias is my particular medical and family history: I'm overweight, in terrible cardiovascular shape, and I have a concentrated family history of heart disease, diabetes, and every cancer imaginable. I also have some
weirdo political / agorist biases as well, which have benefited my aesthetic appreciation of hearty locally-grown vegan cuisine. Finally I probably like salads, bean stews, buckwheat, mushrooms, and fresh-baked bread more than most people do.
That said, I am yet to see the main points made in
The China Study debunked in any substantive way, in spite of the billion-dollar protein supplement and an even bigger meat & dairy industries (one of the most powerful government lobbies in the U.S.) who would go out of their way to resist it. There's a lot of profit in meat and dairy, and those products are actually several times more expensive than we think they are, with the rest of the cost being covered by government subsidies,
limited liabilities, etc.
You often see simplistic studies about the benefits of certain dairy, fish, or meat products that are further simplified by the press, but what is lost are the negative side-effects of those foods, and the fact that you can get the same benefits from plant-based foods with far fewer side-effects. You must remember that animals themselves don't magically make nutrients appear out of thin air - all their nutrients come from plants (or in some cases solar absorption and bacteria, as is the case with Vitamin D and B-12 respectively, but we can manufacture those things much better inside a lab than inside a cow nowadays). If you think about it logically, then passing your nutrients through another animal is economically ridiculous, and it is nutritionally harmful as well because you end up with the animal's fat, hormones, sterols, bacteria, mineral toxins, etc. Yes there's a benefit of the animal concentrating certain nutrients (protein, calcium, B6, etc), but we can easily concentrate them in a lab as well.
[...] Do you think that no one can take in more than 90g of protein in a day (3 meal at 30g), anything more than that will be wasted? [...]
Many protein junkies manage to fit in more meals than that (ex. 7am, 10am, 1pm, 4pm, 7pm, 10pm), and some even drink a protein supplement between meals, but that doesn't mean the absorbed effects add up arithmetically. The upper estimate I've mentioned was 35, but that's just for the central ~90% of the bell curve, there might be "genetic freaks" whose metabolic process is slightly different from most people's... And of course which combinations of amino acids you consume and other dietary details also make a difference. The mathematical algorithms for modeling protein-related processes tend to be very complex - you might be able to optimize your total intake further by getting 5 grams of protein every 15 minutes, though that may impact your alertness and your circulation during physical activity, and there will definitely be a curve of diminishing returns after a certain point.
Edited by Alex Libman, 01 April 2010 - 09:02 PM.