To the editors:

Vaclav Smil’s “Good Eats” is a brilliant and timely essay that should lead us to reflect upon the directions in which modern society is currently developing. I would like to take Smil’s argument a step further and ponder the implications that follow from the entanglement between endosomatic and exosomatic metabolism in modern society. Endosomatic metabolism refers to the food, energy, and nutrients metabolized inside the human body to sustain its physiological activities. Exosomatic metabolism refers to the energy and material metabolized outside the human body to sustain the technical and economic activities guaranteeing our food system. These two forms of metabolism coexist within human society and are profoundly interrelated.¹ In the modern world, we never eat alone. Each bite we take cannot take place without another form of consumption: the energy and materials devoured by the machines and technology that sustain our economy. Many of the uncomfortable facts flagged by Smil are related to this forced commensalism between humans and machines. Consider the following four arguments:

• Exosomatic metabolism has come to dominate the economy, rendering agriculture increasingly irrelevant in today’s society. In developed countries, the agricultural sector contributes a negligible share of GDP and no longer has much influence over the processes involved in the production and consumption of goods and services. Rural areas do not contribute significantly to the economic development of a country and are reliant on subsidies. In post-industrial economies, exosomatic organs, such as production machinery and distribution processes, play an essential role in feeding the urban population as cheaply as possible. The status of agriculture has been reduced to a specialized function of these organs. In this new framework, the farmers have no choice but to follow patterns of urban demand. Their labor having already largely been replaced by machines, the output of farmers is now replaced with imports if it fails to meet the expectations of urban society.²
• The affordability of food—the supply of endosomatic inputs—for urban elites must be contextualized in relation to a society’s exosomatic metabolism. The transformation of the agricultural sector has increased food production at the expense of farmers, who are gradually being eliminated from the workforce. Farmers do not represent a significant share of the paid work sector in any developed country.³ Those driving the economy have found that they can produce much more added value using machines. Adding value guarantees higher incomes, increasing the amount that people can afford to spend on food. But, as illustrated by Engel’s law, food affordability is only a relative measure. The fraction of income spent on food in rich countries is low—below 14% of total expenditure. This amount is still at least five times higher than in the developing world.⁴ The affordability of food in developed countries does not mean that food is cheap. Their ability to absorb higher costs associated with food production means that these societies can use more machines and spend more on food and other goods and services.
• Food has a different meaning for today’s urban elites than it did in traditional societies. The value of food in prosperous societies is dependent on two factors: convenience and social status­. In developed countries, the preparation of food is now a matter of minutes, whereas 70 years ago it required hours. This increased level of convenience has allowed for an influx of women into the workforce, boosting the economic performance of society’s exosomatic metabolism. The social implications associated with consuming a particular cuisine or product are a greater determinant of value than quantity alone. When choices made by consumers are influenced, for the most part, by convenience and social status, preservation of the original nutrients becomes less of a priority and nutrition is neglected as a result.
• The large food losses in the post-harvest sector of developed countries should be considered collateral damage resulting from the takeover of exosomatic metabolism. In 2000, 80% of the energy and money required to get a food product into the hands of US householders was expended in the post-harvest sector—not by the farmers!⁵ In Europe, large quantities of animal feed are imported,⁶ leading to the development of an agricultural sector increasingly specialized in animal products. The transformation of food commodities into food products is continually increasing in complexity, as are the variety of functions that food products are expected to express. These increases in complexity are important contributing factors to the high levels of food waste common in developed countries. Unfortunately, moving excess food from rich to poor countries is far from simple. Moving food is, in fact, more expensive than actually producing it.

These considerations reinforce Smil’s analysis and highlight the urgency in finding solutions to these problems. The complex relationship between endosomatic and exosomatic metabolism makes analyzing the performance of food systems extremely challenging. This is a matter of great concern at a time when food systems around the world are undergoing dramatic changes.

Particularly worrisome is the growing divide between the urban population and the rural population, both in terms of the increasing disparity in their roles and the sense of importance accordance to each. The ever-growing urban populations in developed countries appear to be increasingly unaware of the biophysical processes necessary to maintain their material standards of living. For the urban populace, food comes from supermarkets, energy comes from gas stations and electric plugs, and money comes from automatic teller machines.

Faced with these challenges, I can only endorse Smil’s conclusions. The last thing we need are more technical innovations or new business models. Instead, we should be trying to move away from an economy focused on making money toward a new economy focused on taking care of people, nature, and our own bodies—by choosing good eats.