| There are huge variations in food requirements and processing between individuals. If you look historically, some populations ate mostly plant material, other populations ate almost exclusively meat and animal products, with most populations falling in the middle some place. For millions of years, those populations adapted to their native diets. Many of the current foods available, both plant and animal, probably did not exist in your ancestors' diet at all and are not well adapted for, how much that is the case will depend on your genetics. (hormone laden meat, highly altered wheat, fruits bred to be mostly sugar with few nutrients, fake meat flavored with chemicals, etc). With many of us also carrying a mix of genetics and living far from our original genetic origins, it's a bit of a crap shoot as to what diet may work best for which individual. That's why you can find success and failure stories for almost any kind of diet.
For instance, one person may have a body proficient at converting plant based beta carotene to vitamin A and so not suffer vitamin A deficiency as a vegan, while another that is not genetically well adapted to the conversion may become weak on the same diet. Science has documented huge variations in genetic abilities like these. Also, 'vegan' is not just one kind of diet, one vegan may eat tons of chemical laden fake meat, processed food, and various crap while another may work hard to balance proteins, eat whole fresh foods, find healthier natural fat sources (avocado, coconut oil, etc), chart potential vitamin deficiencies, etc. Diet is not one size fits all. One guy may be super healthy on a given diet and another may become weak on the exact same diet. And each kind of diet has a huge variation in what exactly is actually eaten by a specific individual.
My advice to anyone is go in realizing you are an individual with individual needs. And that the foods that are available now, both plant and animal, are mostly not super natural food sources for anyone, but that still the best we can try to is to eat the most natural we can find (ie not protein bars (vegan or not), extruded mush products that have had all nutrients destroyed by high heat and pressure (cereal), etc.)
Yes, as already mentioned, vegan diet promoters typically have their sense of identity and self wrapped into their eating regimen and so will sometimes protect and defend it in very unscientific and irrational ways. ('this guy here was healthy and lived a long time, so therefore veganism in all it's forms is healthy!" etc) All the other diet programs have members that have similar self identity based diet ideas and have similar bias. But all native tribes have always been omnivores to the best of any scientific knowledge, so IMO, it will take more studying and effort to do a healthy vegan diet plan than it would to be to develop a healthy omnivorous diet plan, you will probably want to be more conscientious about planning your diet, getting complete protein combinations of foods, etc, because your genetics were likely developed on an omnivorous diet. -Eva |