Humans are frugivores.

The human digestive tract, or "gut" as the Pro stated, is actually designed to process proteins from all sources. We sport a "medium length digestive tract which provides flexibility to digest both vegetation and animal proteins."Additionally, we have both "flat molars for grinding and sharp front teeth developed for tearing".Our saliva also contains "carbohydrate digesting enzyme amylase; responsible for the majority of starch digestion".http://tinyurl.com... These features are common among omnivores, as opposed to herbivores with long digestive tracts and square flat molars; these are seen in animals such as cows and sheep.Furthermore, opposable thumbs, fingers type and nail structure have no proven distinction of use outside of general use and protection when it comes to any of the homo species.According to the National Institute of Health, a number of, even most, illnesses humans see are due to cross species virus transfer, which is a relatively new phenomenon: HIV 1 & 2, Influenza, SARS, Avian Flu, Bubonic Plague and many more. Additionally, it is accepted that most illnesses seen in humans today are through cross species virus transfer due to exponentially increased human/animal/insect/rodent/etc. shared living spaces. This has nothing to do with human diet. In fact, the evolution of human diet has increased our immune systems, fighting off illnesses which evolve into new viruses in order to survive within human vessels.http://tinyurl.com... The features described by Pro; claws, long pointy teeth, short digestive tract and highly acidic enzymes are identifiers of CARNIVORES, not of OMNIVORES. These are two completely different dietary categories. Homo species did not evolve to the characteristics as they are omnivores, not carnivores.http://tinyurl.com... Osteoporosis is the inability to produce new bone cells at the rate they are lost, leading to weak and brittle bones. Bone mass reaches peak in your early 20"s; the peak bone mass is the key factor in how likely you are to develop osteoporosis, according to the Mayo Clinic.http://tinyurl.com... Diet is generally incorrectly categorized as CAUSE of osteoporosis, instead diet is discussed here for calcium intake to help slow the development of osteoporosis.Arthritis is caused by two main components: osteoarthritis and rheumatoid arthritis according to the Mayo Clinic, neither of which are caused by diet, but instead are due to immune system attacking your own body, obesity and repetitive physical contact.http://tinyurl.com... Heart failure is due to many factors including diet, however over consumption, along with a combination of other factors such as lack of exercise and smoking, is the only diet habit with major influence on heart health.Constipation also has no direct link to a specific food group, the most likely culprit being excess fiber. According to Mayo Clinic, many other factors instead contribute; see them here:http://tinyurl.com... Humans don"t have crops as birds do for good reason. Birds are small and have small digestive systems, most have a very short and straight tract, little to no digestive enzymes which is why they eat gravel to help pulverize food before regurgitating the gravel among other components I will not bore your with here. For these reasons, avian species have what"s called a "crop", varying in size and shape depending on evolution of need. The major points to know about a "crop" is that is first used as a "doggy bag" for storage, to hold for later consumption as most flight avian species burn a ton of calories during flight; dependent on necessity of lift generation vs in-flight gliding ability. The second reason is to act as a digestive pouch just like a human stomach. Since avian digestive tracts are much smaller and have much weaker digestive fluids as compared to humans, they must digest at a slower pace and with less distance to do so, which means it stays in the "crop" to digest.Here is a web site to start with avian digestive tracts.http://tinyurl.com... According to the American Diabetes Association, Grains are not a source of diabetes, in fact, it is recommended to eat a diet high in whole grains in part when you have diabetes.http://tinyurl.com... Grains also do not cause tooth decay, PROCESSED grains can ATTRIBUTE to tooth decay with a LACK of additional proper diet. This is because the lack of proper nutrition means your body will start to leach nutrients from other sources. Simply eat right.http://tinyurl.com... The claims of nerve issues and injury and genetic expression need to be proven as this just seems outlandish to even think about.Rheumatoid arthritis, multiple sclerosis, asthma, chronic fatigue and depression again are not caused by grains. Please substantiate these claims moving forward.