Human beings have evolved to eat the most varied diet of any species but the limited nature of our modern diet can lead to chronic health problems, claims the author of a new book this week. Is the agricultural foundation of our modern food supply deteriorating human health?
Fad weight loss schemes are based on the erroneous notion that eating only a few specific foods can lead to better health. On the contrary, said University of Arkansas anthropologist Peter Ungar, humans evolved to consume the widest possible range of foods, and limiting that variety can lead to serious health risks.
Rather than restricting one's diet to a select group of foods, a healthier approach to nutrition is to expand the variety of foods you eat, said Ungar. After all, he added, that is what four million years of evolution has designed the human body to do.
"Americans assume that their diets are varied because of the seemingly infinite array of foods available to us," Ungar said. "But if you look at the average American diet, it consists mainly of fat and starch. Occasionally, we throw in some tomatoes."
"Diets that purport to solve that problem by cutting out entire categories of food are taking the wrong approach," he added.
In a new book entitled Human Diet: its Origin and Evolution, Ungar and co-editor Mark Teaford of Johns Hopkins University gathered leading experts in health, nutrition and human evolution to produce a comprehensive review of the human diet.
In the preface to the book, Ungar and Teaford write that "diet changes have far outstripped the capacity of genetic evolution to keep pace with changes in what we eat today."
The discrepancy between our modern eating habits and the metabolic functioning of our bodies has given rise to such diseases as diabetes, cancer and heart disease. Further restriction of food intake, as prescribed by fad diets, has been shown to promote kidney failure, enlargement of the pancreas and iron deficiency.
In the second chapter, a bio-archeologist examines the shift from hunter-gatherer societies to agricultural settlements. He states that the effects of that transition on diet content immediately resulted in a decline in health. Bones and teeth from that transitional period show increased infection, dental disease and physiological stress. The researcher then emphasises that the agricultural foundation of our modern food supply continues to deteriorate human health.
By understanding the diet of our earliest ancestors, researchers hope to identify how modern eating habits have diverged and to assess the physiological consequences of that divergence.
"We are unique in the broad spectrum of foods we take. Primates have a much broader diet than other animals, but we're like super-primates," Ungar explained. "We can eat almost anything we want. That's thanks to our fairly simple gut, our cultural ability to cook and detoxify foods and to our tools, which enable us to break down material that our teeth can't handle."
Nutritional quality has long been inadequate in the modern human diet. But by demonstrating that the human body is designed to consume the broadest possible range of foods, Human Diet suggests that nutritional variety is also lacking.
Ungar claims that as the medical field continues to find links between diet and disease, it becomes evident that the survival of our species may once again hinge on our ability to consume the right foods.