Brenda Brenda:
A human being can not survive without animal products or a substitute (manmade). We are omnivores, not herbivores.
You are incorrect that we cannot survive without animal products.
You are correct that we are omnivores but that is indeed by CHOICE.
There are so many issues that could be discussed but it would make for a seriously long post so I will be brief.
The human system relies upon enzymes and fibre for digestion - animal products have neither.
The entire human digestive tract is designed to handle vegetation...just look at the convolutions and the winding surface area. Meat eating creatures have short and straight digestive tracts. Even human teeth are flat for grinding - please don't choose the 'but we have canine teeth' angle as it would merely show complete ignorance of the subject.
If you want to break it down to 'what is natural' think of it this way: before humans developed the tools and methods to trap and contain animals or the weapons to hunt and kill animals which ones could they chase down and catch? The answer will tell you much.
Humans are the only species to consume the glandular extract of another species (dairy products).
The bottom line is that we CHOOSE to consume animal products but most humans should consume about 80-90% less than they do...and furthermore, if everyone in North America would cut their animal product intake by a mere 5% we would have the 'answer' for world hunger.