In order to grow abundantly, plants consume carbon dioxide, water, and nutrients from the soil. Likewise, herbivorous animals consume plants whereas carnivorous animals consume other animals. Insects eat a wide variety of foods, including plants, fruit, other insects, detritus (dead leaves, stems, and twigs), and even blood. Many types of bacteria and fungi recycle decomposing matter. Whales, the top predator in the oceans, may consume more than a ton of plankton per day in addition to fish, squid, and other crustaceans.
Every member of every species excepting humans (Homo sapiens sapiens) obtains everything it needs from the environment. Modern humanity is the only species for which the abundance provided by the global ecosystem is insufficient.
For instance, mountain lions, raccoons, and coyotes don't need sleeping pills. But humans spend more than $1.5 billion per year on the sleep aid Ambien. Dolphins, antelope, and bluebirds don't have problems with blood glucose levels. In stark contrast, the annual cost of diabetes medications in the United States was $12.5 billion in 2007. In the wild, oak trees, tuna, and elephants don't need nutritional supplementation. Humans, however, spend more than $23 billion annually in the United States alone. What is wrong with this picture?
As a species, humans have the unprecedented ability to manipulate and drastically alter the world in which we live. Also aside from epidemic infectious disease, there exists no natural check on human population growth. As populations expand, resources become scarce. Populations flocking to urban enclaves not only leave behind the countryside but also local sources of fresh fruits, vegetables, meat and poultry. Canning, packaging, and transportation of food over long distances become necessary to supply the energy needs of cities. But only calories and not much else are obtained by these methods. Energy is provided but food quality is substantially reduced.
Chronic disease becomes widespread. Diabetes, cardiovascular disorders including high blood pressure, heart attacks, and stroke, and obesity are all the direct result of a severely compromised food supply.1,2,3
Our disconnect from the natural world poses many additional challenges. Our bodies were designed to meet the demanding physical requirements of a hostile environment. But for the most part we don't do physical work anymore. If we don't find satisfactory substitutes for strenuous physical activity our musculoskeletal, metabolic, and endocrine systems easily deteriorate. The consequences include osteoporosis, chronic aches and pains, gastrointestinal problems, and anxiety and depression.
It takes a lot of effort to maintain good health when we're so far removed from the natural world. We need to make sure our diets are healthy and we need to get sufficient and regular strenuous exercise. The short- and long-term benefits include happiness, self-esteem, and ongoing well-being.