The American diet and the American waistline are expanding, and the effects are drastic. Concurrently, the population of the world is expanding, and the competition for natural resources (soil, land, energy, water, air) is intensifying. All these events are linked because of environmental impact.
Regardless of what you think about global warming, you’ll likely agree that the American lifestyle, advancements across the globe, and the world’s ballooning human population are affecting the state of the planet. But all is not lost; there are plenty of easy changes you can make to your daily diet and training regime that will reduce your carbon footprint while improving your health.
People in the know talk often about carbon footprint. Simply put, carbon footprint is a way to measure the impact that human activities have on the environment through greenhouse gas emissions (GHGEs). GHGEs—namely, carbon dioxide (CO2), methane, nitrous oxide and chlorofluorocarbon—are associated with climate changes and have an impact on the entire environment. The more dependent we are on fossil fuels, the larger our carbon footprint is.
Predictably, Americans are responsible for more than 20 tons of CO2 per capita annually (Walsh & Sharples 2008). How does that compare with the rest of the world? A recent study by researchers at the Massachusetts Institute of Technology found that even a homeless American has an average carbon footprint of 8.5 tons of CO2—more than twice the global average of 4 tons (Walsh & Sharples 2008; Geagan 2009).
According to the United Nations Food and Agriculture Organization, the typical American diet now weighs in at more than 3,700 calories per day (Tidwell 2009) This Western style of eating—usually loaded with red meat, processed meats, refined grains and sugars, animal fats like butter and cheese, high-calorie liquids, heavily processed foods and convenience foods—is not at all “hybrid” in style, to use an auto design analogy. Instead it can be more accurately described as an SUV style of eating. Similar to many gas-guzzling, off-road vehicles, the Western diet is extravagant in regard to fuel use and emissions.
Along the same lines, this “Hummer” style of eating is high in calories and low in whole grains, beans, fruits and vegetables; as such, it is associated with high rates of obesity and chronic diseases. Conversely, a green (or low-carbon) diet calls for consumption of locally grown and seasonal food items, greatly reduced intake of meat and dairy, avoidance of processed and packaged foods, and an overall focus on reducing food waste.
If you’re asking, “How, exactly, can one’s diet and waistline affect the environment?” here are some points to ponder. While Americans don’t stroll around continually “emitting” greenhouse gases the way ruminant animals do, we indirectly cause vast amounts of GHGEs every day. Owing to our driving habits and excessive consumption of various natural resources, we have an enormous carbon footprint compared with the rest of the world. By making small, sustainable changes, beginning with our diet and activity habits, we can start to move toward a green way of life. In essence, by eating and existing with the planet in mind, we can effectively reduce GHGEs and “be green.”
The way we eat—including our food choices, portion sizes and lifestyle (dining out vs. cooking at home; frozen commercial casserole vs. homemade lasagne)—has a significant impact on daily GHGEs; food production accounts for one third of GHGEs on account of the many steps it takes to get food from farm to table (Geagan 2009; Harmon & Gerald 2007). Steps in food production include harvesting, processing, heating and cooling, storage, packaging and transportation (Harmon & Gerald 2007). Some food items go through many of these steps multiple times.
For example, consider the 350+ million acres of cropland that exist in the contiguous 48 states, some of which are devoted to growing corn (NRCS 2007). When a corn crop is harvested, the end use determines how and where it is processed. For example, if the end product is corn syrup, the crop is transported to a facility where each ear of corn is processed and heated until every kernel is transformed.
After this conversion takes place, the syrup is packaged and transported to another facility, where it is stored at the proper temperature (heating and cooling comes into play) until it is needed to sweeten or even thicken an item. At this point, the corn syrup, commonly used as a sweetener in processed items like ice cream or commercial cookies, is transported to yet another facility, where it is added to other (processed) products in order to make the final product. The final product—be it cookies or ice cream or something else—also requires processing, heating or cooling, storage and transportation. This final product may be stored and transported many, many more times before it arrives on your table. With this one example, it is easy to see what an impact our food choices have on the environment and the positive impact we can make if we reduce our intake of processed and packaged foods.
Besides the fossil fuels used to process and package foods—food items that make up a third of the total food consumption in the U.S. (Eshel & Martin 2006)—another perpetrator of high CO2 emissions is a diet high in animal protein. This is because (1) it takes 6–17 times more land to produce meat protein than it does to produce vegetable protein (Harmon & Gerald 2007); and (2) livestock production accounts for a whopping 18% of the world’s total greenhouse gases (Tidwell 2009).
It so happens that ruminants, such as sheep and cows, generate large amounts of greenhouse gases owing to their, well, “output,” which takes the form of methane and nitrous oxide—both many times more powerful than CO2 at trapping heat. For these reasons and others, reducing consumption of animal protein has a powerful impact on the environment; according to researchers from Cornell University, vegans (who consume no animal products) use 250 fewer gallons of oil annually, and lacto-ovo vegetarians use 160 fewer gallons, compared with their carnivorous counterparts (Tidwell 2009).
Any fitness professional, avid athlete or registered dietitian knows that athletes, especially those in heavy training, require more protein than sedentary individuals. Because of the need for muscle growth and recovery, the protein needs of athletes are indeed slightly higher than the Recommended Dietary Allowance (RDA), which is 0.8 gram per kilogram per day for adults (Rodriguez, DiMarco & Langley 2009; IOM 2002). That being said, the majority of athletes consume enough protein to surpass the RDA and recover appropriately. One can assume that the majority of the protein they consume comes from animal sources (according to the Vegetarian Resource Group, only 3% of the U.S. population is vegetarian), which means that athletes have a large carbon footprint. Indeed, as noted earlier, the average American who eats a diet high in animal products (meat, dairy, eggs, fish, etc.) emits 20 tons of CO2 each year—five times the international average.
Consider the following:
- It takes an estimated 7 pounds of corn and 2,500 gallons of water to put 1 pound of weight on a steer (Geagan 2009).
- Producing 2.2 pounds of beef requires the same amount of energy that it takes to light a 100-watt bulb for approximately 20 days (Geagan 2009).
- Producing energy (i.e., consumable calories) from plant sources is a far more efficient process than producing energy from animal sources. On average, 2 calories of fossil fuel energy are required to produce 1 calorie of plant food, whereas 20–80 fossil fuel calories are needed to produce each calorie of animal protein. In addition, it takes five times more water, a vital natural resource, to grow grains used for animal feed than it does to grow fruits and vegetables (Geagan 2009).
In light of these facts, it becomes obvious that by relying on vegetarian sources of protein, an athlete, or any meat-loving gastronome for that matter, can reduce his or her carbon footprint while still meeting the RDA (Geagan 2009).
Added bonus? While 34% of American adults are overweight and another 34% are obese (CDC 2010), the obesity rate among vegetarians ranges from 0% to 6%, with vegetarians boasting an average body weight 3%–20% lower than that of meat eaters (Geagan 2009)!
Many consumers think that because they are “organic eaters” they are also “green eaters.” Not necessarily. Generally speaking, there are countless benefits when it comes to eating organic fare, namely fewer “unexpected” food additives such as hormones and pesticides. It’s true that organic products on the whole tend to be green—given the savings in fossil fuels that are not needed to manufacture or ship them or to apply nitrogen-based fertilizers and pesticides. However, assorted organic products (i.e., overly processed, packaged items) are similar to their conventional counterparts in terms of GHGEs. When debating which item has the least environmental impact, first consider the steps the product has gone through. A savvy consumer must consider processing and transportation costs when considering any product, organic or conventional.
Currently, more than 800 million tons of food are shipped around the planet each year (four times the amount that shipped in 1960) and, on average, food travels 25% farther than it did 20 years ago (Geagan 2009). Given that the average trip is approximately 1,500–2,500 miles from farm to table, those organic Chilean strawberries you enjoyed last winter had a huge carbon footprint in comparison with the domestic citrus fruit you could have purchased (with change to spare). Need more convincing? A 2007 study out of Cranfield University in England found that after considering all factors, organic, free-range chickens had a 20% greater impact on the environment than conventionally raised birds (Tidwell 2009).
Why? Turns out that “sustainable” chickens take longer to raise (i.e., require fuel for labor and equipment) and eat more feed.
The concept of reducing one’s dietary impact on the environment is certainly not new, but it is becoming more prevalent. Indeed, in a 2010 survey of more than 1,500 chefs, the National Restaurant Association asked participants to rank 226 items in regard to how trendy they would be in the upcoming year. The association discovered that out of all possible trends, multiple environmentally conscious options ranked among the top 15 menu trends of 2011. The hottest trends? Locally grown/produced produce and potables; locally sourced meats and seafood; sustainable products; and use of organic produce. As the threat of global warming continues to headline the nightly news, it is clear that changes need to be made in order to protect the environment for current and future generations. Fortunately, small changes made at home can create a world of difference.
Eshel, E., & Martin, P.A. 2006. Diet, energy, and global warming. Earth Interactions, 10, 1–17.
Geagan, K. 2009. Go Green Get Lean. New York: Rodale.
Harmon, A.H., & Gerald, B.L. 2007. Position of the American Dietetic Association: Food and nutrition professionals can implement practices to conserve natural resources and support ecological sustainability. Journal of the American Dietetic Association, 107, 1033–43.
IOM (Institute of Medicine, Food and Nutrition Board). 2002. Dietary reference intakes: Energy, carbohydrates, fiber, fat, fatty acids, cholesterol, protein and amino acids. Washington, DC: National Academies Press.
National Restaurant Association, Chef Survey: What’s Hot in 2011. www.restaurant.org/pdfs/research/whats_hot_2011.pdf; retrieved Jan. 27, 2011.
Natural Resources Conservation Service (NRCS), U.S. Department of Agriculture. 2007. Natural Resources Inventory, 2007 Annual NRI released May 2006. www.nrcs.usda.gov/technical/NRI/2007/2007_NRI_summary.pdf; retrieved Jan. 20, 2011.
Rodriguez, N.R., DiMarco, N.M., & Langley, S. 2009. Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. Journal of the American Dietetic Association, 109, 509–27.
Tidwell, M. 2009. The low-carbon diet. Audubon, 111 (1), 46–66.
Vegetarian Resource Group. www.vrg.org/press/2009poll.htm; retrieved Feb. 3, 2011.
Walsh, B., Sharples, T. 2008. Sizing up carbon footprints. Time, 171 (21), 53–55.