human beings have been eating oatmeal and rice and wheat bread since the dawn of time... 
oh brother
did you even research your fad diet before you adopted it. Here 5 seconds of googling found me the paleo wiki:
http://en.wikipedia.org/wiki/Paleolithic_dietCriticism of the Paleolithic diet
[edit] Comparative life expectancy
One of the most frequent criticisms of the Paleolithic diet is that it is unlikely that preagricultural hunter-gatherers suffered from the diseases of modern civilization simply because they did not live long enough to develop these illnesses, which are typically associated with old age.[12][16][86][87][88] In response to this argument, advocates of the paleodiet state that while Paleolithic hunter-gatherers did have a short average life expectancy, modern human populations with lifestyles resembling that of our preagricultural ancestors have no or little diseases of affluence, despite sufficient numbers of elderly.[16][89]
[edit] Causes of the diseases of affluence
Critics further contend that food energy excess, rather than the consumption of specific novel foods, such as grains and dairy products, underlies the diseases of affluence. According to Geoffrey Cannon,[12] science and health policy advisor to the World Cancer Research Fund, humans are designed to work physically hard to produce food for subsistence and to survive periods of acute food shortage, and are not adapted to a diet rich in energy-dense foods.[90] Similarly, William R. Leonard, a professor of anthropology at Northwestern University, states that the health problems facing industrial societies stem not from deviations from a specific ancestral diet but from an imbalance between calories consumed and calories burned, a state of energy excess uncharacteristic of ancestral lifestyles.[91]
[edit] Evolutionary logic
The evolutionary assumptions underlying the Paleolithic diet have also been disputed.[13][19][27] According to Alexander Ströhle, Maike Wolters and Andreas Hahn,[19] with the Department of Food Science at the University of Hannover, the statement that the human genome evolved during the Pleistocene (a period from 1,808,000 to 11,550 years ago) is resting on an inadequate, but popular gene-centered view of evolution. They argue that evolution of organisms cannot be reduced to the genetic level with reference to mutation and that there is no one to one relationship between genotype and phenotype.[92]
High-insulinogenic foods, like refined grains, were introduced in the human diet only about 200 years ago.[93]They further question the notion that 10,000 years since the dawn of agriculture is a period not nearly sufficient to ensure an adequate adaptation to agrarian diets.[19] Refering to Wilson D.S. (1994),[94] Ströhle et al. argue that "the number of generations that a species existed in the old environment was irrelevant, and that the response to the change of the environment of a species would depend on the hereditability of the traits, the intensity of selection and the number of generations that selection acts."[93] They state that if the diet of Neolithic agriculturalists had been in discordance with their physiology, then this would have created a selection pressure for evolutionary change and modern humans, such as Europeans, whose ancestors have subsisted on agrarian diets for 400–500 generations should be somehow adequately adapted to it. In response to this argument, Wolfgang Kopp states that "we have to take into account that death from atherosclerosis and cardiovascular disease (CVD) occurs later during life, as a rule after the reproduction phase. Even a high mortality from CVD after the reproduction phase will create little selection pressure. Thus, it seems that a diet can be functional (it keeps us going) and dysfunctional (it causes health problems) at the same time."[93] Moreover, S. Boyd Eaton and colleagues have indicated that "comparative genetic data provide compelling evidence against the contention that long exposure to agricultural and industrial circumstances has distanced us, genetically, from our Stone Age ancestors."[16] According to Kopp, the implementation of high-glycemic and high-insulinogenic food, like refined cereals and sugars, into human nutrition only about 200 years, or 10 generations, ago, occurred too recently on an evolutionary time scale for the human genome to adjust.[93]
According to Ströhle et al.,[19] "whatever is the fact, to think that a dietary factor is valuable (functional) to the organism only when there was ‘genetical adaptation’ and hence a new dietary factor is dysfunctional per se because there was no evolutionary adaptation to it, such a panselectionist misreading of biological evolution seems to be inspired by a naive adaptationistic view of life."[95][96]
Katharine Milton, a professor of physical anthropology at the University of California, has also disputed the evolutionary logic upon which the Paleolithic diet is based. She questions the premise that the metabolism of modern humans must be genetically adapted to the dietary conditions of the Paleolithic.[13] According to Milton,[13] "there is little evidence to suggest that human nutritional requirements or human digestive physiology were significantly affected by such diets at any point in human evolution."[97][98][99][100]
[edit] Criticism of low-carbohydrate and high-protein versions
The high protein and low-carbohydrate diet[e] recommended by Loren Cordain and colleagues based on the dietary patterns of worldwide modern-day hunter-gatherers[45][49][101] has attracted a number of criticisms,[12][102] including the following:
[edit] Therapeutic merits
It has been argued that relative freedom from degenerative diseases was, and still is, characteristic of all hunter-gatherer societies irrespective of the macronutrient characteristics of their diets.[18][103][104] Katharine Milton states that "hunter-gatherer societies, both recent and ancestral, displayed a wide variety of plant-animal subsistence ratios, illustrating the adaptability of human metabolism to a broad range of energy substrates. Because all hunter-gatherer societies are largely free of chronic degenerative disease, there seems little justification for advocating the therapeutic merits of one type of hunter-gatherer diet over another."[103]
According to Marion Nestle, a professor in the Department of Nutrition and Food Studies at New York University, judging from research relating nutritional factors to chronic disease risks and to observations of exceptionally low chronic disease rates among people eating vegetarian, Mediterranean and Asian diets, it seems clear that plant-based diets are most associated with health and longevity.[11][21]
Ströhle, Wolters and Hahn[19] argue that hunters like the Inuit, who traditionally obtain most of their dietary energy from wild animals and therefore eat a low-carbohydrate diet,[105] seem to have a high mortality from coronary heart disease,[106] and that many populations of horticulturists, pastoralists and simple agriculturists living today are ingesting a high-carbohydrate diet without having signs and symptoms of CHD.[57][59][107][108][109] In response to this criticism, Wolfgang Kopp states that "carbohydrate food, consumed by hunter-gatherers, is high in fiber and low-glycemic in effect,[110][111] eliciting small amounts of insulin only. [...] Are high-carbohydrate diets atherogenic per se? Not if they have a low glycemic load. In this point, Stroehle et al. are right. However, it is the question, whether diets high in low-glycemic plant food (which is relatively high in indigestible fiber and relatively low in carbohydrate) should be labeled as “high-carbohydrate” diets."[93] Kopp also says that it is very likely that diets with only a moderately increased glycemic load are atherogenic to some degree.[66][112]
According to Erica Frank, professor of health care at the University of British Columbia, eating an animal also involves absorbing the toxins stored in its body fat. She quotes the EPA: "The average American intake is between 300 and 500 times the safe daily dose of dioxin."[20] She argues that dioxin, which is stored in animal fat, is a cancer-causing substance and disrupts hormones and the immune system. "People would be in error if they think they're doing themselves a service by eating bison."[20]
[edit] Anthropological evidence
Carbohydrate rich root vegetables may have been eaten in high amounts by Paleolithic humans.[113]Critics have argued that there are insufficient data to determine the average daily intake of animal and plant foods by Paleolithic humans.[13][14][21][96][114] Furthermore, according to Katharine Milton, "data from ethnographic studies of nineteenth and twentieth century hunter-gatherers, as well as historical accounts and the archeological record, suggest that ancestral hunter-gatherers enjoyed a rich variety of different diets. Thus estimates of nutrient proportions for "the Paleolithic diet" are hypothetical, at best."[13] Echoing Milton's criticism, Ströhle et al.[19] argue that it is questionable if all hunter-gatherers living between 150,000 and 10,000 years ago in different geographical regions ate a low-carbohydrate diet.[1][115][116] They indicate that, because the plant–animal subsistence ratios of contemporary hunter-gatherers vary in a remarkable manner (0–90% food from gathering; 10–100% food from hunting and fishing),[117][118] it is likely that the macronutrient intake of preagricultural humans varied enormously.[115]
They also refer to a hypothesis (the 'Plant underground storage organs hypotheses') that suggests that carbohydrate tubers were eaten in high amounts by our preagricultural ancestors.[113][119][120][121] They add:[19] "Provided that humans are incapable of metabolizing high amounts of dietary protein and given the fact that wild African mammals are relatively low in fat, a diet supplemented with carbohydrates from tubers seems to be more efficient in meeting the energy requirements of early hunters and gatherers than a diet based on lean meat."[122][123] Ströhle et al. further mention that Staffan Lindeberg, an advocate of the Paleolithic diet, has accounted for a plant-based diet rich in carbohydrates as being consistent with the human evolutionary past.[1][3]
