UN Lays Out the Case for Plant-Based Diets

July 20, 2024 / Nutrition / By

Before we get into the United Nations (UN) report entitled “Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems”, we would like to address some of the headlines we’ve read covering this report.

Yahoo News: “People ‘have to turn to vegetarian or vegan diets’ to stop climate change, UN report warns.”

The Daily Mail: “Humans must adopt vegetarian or vegan diets to stop climate change, UN report warns.”

Headlines like these are ‘clickbait’. With clickbait, they are meant to provoke an emotional response that is one of panic, inspiration or defeat.

We performed a keyword search through the over 1,500 page UN report for “vegan” specifically looking for these imperative statements. Maybe we missed something because we could not find them.

The BBC News’ reporting on the subject was more in line with what the UN was actually stating, “A major report on land use and climate change says the West’s high consumption of meat and dairy produce is fueling global warming…But scientists and officials stopped short of explicitly calling on everyone to become vegan or vegetarian.”

The UN recognizes that food is very personal for many people and it is tied to religion, morals, values, convictions, socioeconomic status, society, culture or health. Indeed, for many of us companion pet parents, we are even more passionate about what our pets eat than what we eat, and cost has to factor in for many of us.

What did stand out to us was the summary statement the UN included twice in Chapter 5: Food Security:

“In their systematic review, Nelson et al. (2016) conclude that, in general, a dietary pattern that is higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in animal-based foods is more health promoting and is associated with lesser environmental impact (GHG emissions and energy, land, and water use) than is the current average ‘meat-based’ diet.”

One of the current diet trends in the West is gluten-free or grain-free diets, and more of an emphasis on calories from protein and fat instead of carbohydrates. Indeed, we often experience these pendulum shifts over time. In the 1990’s, the diet trend was the exact opposite.

So, if you are following the current diet trend or something similar and your body feels good on it, you may read this statement from the UN and feel defeated. Your mind might race through this thought process:

“I gave up whole grains because they make me fat. I recognize that the consumption of red meat can lead to heart disease, but I only consume it once every two weeks for the bioavailability of iron. Vegetarian and vegan diets are often linked to lower levels of bad cholesterol, but I feel like my body repairs better on a meat-based diet. Nuts – OK. But, I’m allergic to almonds, so that means pistachios. Pistachios contain aflatoxins, though, and that’s a fungus. Legumes (beans) are high in lectins, which could cause obesity, dementia or cancer if they are toxic. Plus, beans give me gas. I can’t win.”

Agreed, overwhelming.

This begets the questions:

“How do I modify my diet to do my part to stave off climate change, but try to maintain my personal health? What about my companion pet’s role to help stop climate change?”

We will pull out facts from the report that we found shocking and provide tips on how you can make changes to do your part.

Before we proceed, think about all that goes into food production and the losses: erosion, fertilizers that cause dead zones in waterways, herbicides, processing, gas powered combines, transportation, irrigation, tractors, food for livestock, plowed land that rips away natural resources, et cetera et cetera. Indeed, the food in an average shopping cart has traveled 1,500 miles.

4 key topics stood out to us in chapter 5 of the UN report that we extracted:

  • Food loss and waste
  • Overconsumption
  • Animal-based diets versus plant-based diets
  • Processed food

Of course, the topics overlap.

Food Waste

  • Food loss is defined as the reduction of edible food during production, postharvest, and processing, whereas food discarded by consumers is considered as food waste (FAO 2011b). Combined food loss and waste amount to a third of global food production (high confidence). During 2010-2016, global food loss and waste equaled 8–10% of total greenhouse gas (GHG) emissions (medium confidence); and cost about USD 1 trillion per year (FAO 2014b) (low confidence).
  • A large share of produced food is lost in developing countries due to poor infrastructure, while a large share of produced food is wasted in developed countries (Godfray et al. 2010). Changing consumer behavior to reduce per capita overconsumption offers substantial potential to improve food security by avoiding related health burdens (Alexander et al. 2017; Smith 2013) and reduce emissions associated with the extra food (Godfray et al. 2010). In 2007, around 20% of the food produced went to waste in Europe and North America, while around 30% of the food produced was lost in sub-Saharan Africa (FAO 2011b). During the last 50 years, the global food loss and waste increased from around 540 Mt in 1961 to 1630 Mt in 2011 (Porter et al. 2016).
  • At a global scale, loss and waste of milk, poultry meat, pig meat, sheep meat, and potatoes are associated with 3% of the global agricultural N2O emissions in 2009 (Reay et al. 2012). For the United States, 35% of energy use, 34% of blue water use, 34% of GHG emissions, 31% of land use, and 35% of fertilizer use related to an individual’s food-related resource consumption were accounted for as food waste and loss in 2010 (Birney et al. 2017).
  • When land use change for agriculture expansion is also considered, halving food loss and waste reduces the global need for cropland area by around 14% and GHG emissions from agriculture and land use change by 22–28%.

Commentary on Food Waste

We really should be ashamed of ourselves simply based on this statistic:

“For the United States, 35% of energy use, 34% of blue water use, 34% of GHG emissions, 31% of land use, and 35% of fertilizer use related to an individual’s food-related resource consumption were accounted for as food waste and loss in 2010 (Birney et al. 2017).”

Harvest Public Media reported in 2014:

“According to the U.S. Environmental Protection Agency, 20 percent of what goes into municipal landfills is food. Food waste tipped the scale at 35 million tons in 2012, the most recent year estimates are available.

The enormous amount of wasted food is weighing on our food system. An incredible 40 percent of the available food supply in the U.S. is never eaten, according to research funded by the National Institutes of Health.”

Tips to Minimize Food Waste

If you are tossing out or composting more than the rind of an orange, the stem of a tomato, the peel of a banana (you get the idea), we challenge you to:

  • Clean out your cupboards and pantries by eating or donating the food. Do not let it expire!
  • Only keep a three-day emergency supply of canned foods that does not need to be heated in case your power goes out due to a hurricane, wildfire or violent thunderstorm. A good example is beans. Don’t stockpile food because it is on sale unless you are going to eat it!
  • Opt for fresh foods.
  • Find out how to keep foods fresh longer. For instance, kale can “go limp” fairly quickly. Once this happens, cut off the bottom of the stem and place it in warm water. It perks back up in no time. The same goes for basil.
  • Dehydrate meats, fruits and vegetables for snacks. You can give several of these foods as treats to your companion dog.
  • Preserve fruits and vegetables in glass jars at home.
  • Freeze fruits, meats and vegetables.
  • Now, canning, freezing and dehydrating are great methods, so long as you eat the food in a timely manner.
  • Save your receipts! Nothing is more aggravating than to find out your food has already spoiled before you even get it home. We’re sure we have all purchased bagged leafy vegetables like lettuce or spring mixes that is already gooey or became gooey overnight. Return it. This sends a signal through the supply chain to improve their processes.
  • Buy a salad spinner. Salad spinners really help preserve leafy green vegetables by whisking the water away. Then, you will no longer have the immediate issue of gooey lettuce.
  • Only cook what you need or eat your leftovers.

Overconsumption

  • Similar to food waste, overconsumption, defined as food consumption in excess of nutrient requirements, leads to GHG emissions (Alexander et al. 2017). In Australia for example, overconsumption accounts for about 33% GHGs associated with food (Hadjikakou 2017). In addition to GHG emissions, overconsumption also can lead to severe health conditions such as obesity or diabetes. Over-eating was found to be at least as large a contributor to food system losses (Alexander et al. 2017). Similarly, food system losses associated with consuming resource-intensive animal-based products instead of nutritionally-comparable plant-based alternatives are defined as ‘opportunity food losses.’ These were estimated to be 96, 90, 75, 50, and 40% for beef, pork, dairy, poultry, and eggs, respectively, in the US (Shepon et al. 2018).
  • The analysis of climate change and food insecurity has expanded beyond undernutrition to include the overconsumption of unhealthy mass produced food high in sugar and fat, which also threatens health in different but highly damaging ways and the role of dietary choices and consumption in greenhouse gas emissions.
  • Globally, as the availability of inexpensive calories from commodity crops increases, so does per capita consumption of calorie-dense foods (Ng et al. 2014; NCD-RisC 2016a; Abarca-Gómez et al. 2017; Doak and Popkin 2017). As a result, in every region of the world, the prevalence of obesity (body mass index >30 kg/m2) and overweight (body mass index range between normality [18.5-24.9] and obesity) is increasing. There are now more obese adults in the world than underweight adults (Ng et al. 2014; NCD-RisC 2016a; Abarca-Gómez et al. 2017; Doak and Popkin 2017). In 2016, around two billion adults were overweight, including 678 million suffering from obesity (NCD-RisC 2016a; Abarca-Gómez et al. 2017). The prevalence of overweight and obesity has been observed in all age groups.
  • Around 41 million children under five years and 340 million children and adolescents aged 5–19 years were suffering from overweight or obesity in 2016 (NCD-RisC 2016a; FAO et al. 2017; WHO 2015). In many high-income countries, the rising trends in children and adolescents suffering from overweight and obesity have stagnated at high levels; however, these have accelerated in parts of Asia and have very slightly reduced in European and Central Asian lower and middle-income countries (Abarca-Gómez et al. 2017; Doak and Popkin 2017; Christmann et al. 2009).

Tips to Reduce Overconsumption

Let’s admit it: In the United States, we are overserved by restaurants and grocery stores, which is contributing to excess food consumption. Our perceptions have become that the more bountiful the plate, the more bang for our buck. This overconsumption elicits the emotional responses of “winning” and “satisfaction”.

According to the National Institutes of Health, we need 5.5-6 ounces of protein per day.

The American Heart Association, says a serving size is typically:

  • Fish (preferably non-fried) – 3.5 ounces
  • Beef (preferably lean) – 3 ounces
  • Chicken (preferably skinless) – 3 ounces
  • Beans & legumes – 1/2 cup cooked
  • Eggs – 1 egg or 2 egg whites
  • Yogurt (low-fat or fat-free) – 6 ounces
  • Milk (low-fat or fat-free) – 1 cup

In general, a serving size should fit into the palm of your hand.

So why do grocery stores sell 6-8 ounces of fresh chicken or beef? Why do restaurants dish out 8 oz. of the same? Do they think we all eat toast for breakfast?

For years, Weight Watchers has told its members to cut their portion sizes in half at restaurants and take the rest home. Clearly, this is what all of us should be doing. Of course, eat it the next day.

You can split a meal with your companion.

Another option is to ask restaurants to withhold something from the meal. Think about it, when you order an entrée at most restaurants, it usually comes with a side salad and a side of something else. Ask them to withhold the side. Now, this can be hard because your plate may look “bare”, but you get used to it.

Packages of boneless breast chicken and sirloin beef at grocery stores are generally sold in 2 or 4 packs and weigh 6-8 ounces. When you get home, cut them in half and freeze the portion you won’t be using before the expiration date.

If you are uncomfortable cutting the meat into pieces, ask the butcher to do it.

According to the United States Department of Agriculture, a typical can of beans is 15.5 oz. Most of us might think that can is holding 2 servings. It’s not, it’s holding 3.5 servings.

The added bonus is if you think more consciously about your personal overconsumption in relation to climate change, you will see pocketbook savings and might drop a few pounds, which will help reduce your risk of chronic diseases like diabetes.

Animal-Based vs Plant-Based

  • Godfray et al. (2018) updated Nelson et al. (2016), a previous systematic review of the literature on environmental impacts associated with food, and concluded that higher consumption of animal-based foods was associated with higher estimated environmental impacts, whereas increased consumption of plant-based foods was associated with estimated lower environmental impact. Assessment of individual foods within these broader categories showed that meat – sometimes specified as ruminant meat (mainly beef) – was consistently identified as the single food with the greatest impact on the environment, most often in terms of GHG emissions and/or land use per unit commodity.
  • All estimates agree that cattle are the main source of global livestock emissions (65–77%). Livestock in low and middle-income countries contribute 70% of the emissions from ruminants and 53% from monogastric livestock (animals without ruminant digestion processes such as sheep, goats, pigs, and poultry), and these are expected to increase as demand for livestock products increases in these countries. In contrast to the increasing trend in absolute GHG emissions, GHG emissions intensities, defined as GHG emissions per unit produced, have declined globally and are about 60% lower today than in the 1960s. This is largely due to improved meat and milk productivity of cattle breeds (FAOSTAT 2018; Davis et al. 2015).
  • The emissions intensities of red meat mean that its production has a disproportionate impact on total emissions (Godfray et al. 2018). For example, in the US 4% of food sold (by weight) is beef, which accounts for 36% of food-related emissions (Heller and Keoleian 2015). Food-related emissions are therefore very sensitive to the amount and type of meat consumed. However, 100 g of beef has twice as much protein as the equivalent in cooked weight of beans, for example, and 2.5 times more iron. One can ingest only about 2.5 kg of food per day and not all food items are as dense in nutrition.
  • There is therefore robust evidence with high agreement that the mixture of foods eaten can have a highly significant impact on per capita carbon emissions, driven particularly through the amount of (especially grain-fed) livestock and products.
  • The main reason why reducing meat consumption is an adaptation measure is because it reduces pressure on land and water and thus our vulnerability to climate change and inputs limitations (Vanham et al. 2013). For animal feed, ruminants can have positive ecological effects (species diversity, soil carbon) if they are fed extensively on existing grasslands.
  • Whilst sustainable diets need not necessarily provide more nutrition, there is certainly significant overlap between those that are healthier (e.g., via eating more plant-based material and less livestock-based material), and eating the appropriate level of calories. In their systematic review, Nelson et al. (2016) conclude that, in general, a dietary pattern that is higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in animal-based foods is more health promoting and is associated with lesser environmental impact (GHG emissions and energy, land, and water use) than is the current average “meat-based” diet.

Tips on Reducing Animal-Based Diets

  • If you do eat beef more than twice per week, try to reduce your consumption to once per week.
  • We challenge you to start a vegan diet day once per week and slowly increase it to three or more days a week.
  • Vegan dog food is highly controversial. However, studies have shown that dogs derive sufficient nutritional needs from some commercial vegan diets that meet the Association of American Feed Control Officials (AAFCO) standards. Just like our challenge to you, consider feeding your dog a vegan or vegetarian diet once per week.
  • If you do choose to eat beef, choose grass-fed instead of grain-fed.

Processed Foods

  • However, transition from traditional diets based on local foods to a commercial crop-based diet with high fats, salt, sugar and processed foods, increased the incidence of non-communicable diseases, such as diabetes, obesity, heart diseases and certain types of cancer.
  • Most of the GHGs emitted from food processing are a result of the use of electricity, natural gas, coal, diesel, gasoline or other energy sources. Cookers, boilers, and furnaces emit carbon dioxide, and wastewater emits methane and nitrous oxide. The most energy20 intensive processing is wet milling of maize, which requires 15% of total US food industry energy (Bernstein et al. 2008); processing of sugar and oils also requires large amounts of energy.
  • The analysis of climate change and food insecurity has expanded beyond undernutrition to include the overconsumption of unhealthy mass28 produced food high in sugar and fat, which also threatens health in different but highly damaging ways and the role of dietary choices and consumption in greenhouse gas emissions.
  • Consumption of healthy and sustainable diets presents major opportunities for reducing GHG emissions from food systems and improving health outcomes (high confidence). Examples of healthy and sustainable diets are high in coarse grains, pulses, fruits and vegetables, and nuts and seeds; low in energy-intensive animal-sourced and discretionary foods (such as sugary beverages); and with a carbohydrate threshold. Total mitigation potential of dietary changes is estimated as 1.8-3.4 GtCO2eq yr-1 by 2050 at prices ranging from 20-100 USD/tCO2 (medium confidence). This estimate includes reductions in emissions from livestock and soil carbon sequestration on spared land, but co-benefits with health are not taken into account. Mitigation potential of dietary change may be higher, but achievement of this potential at broad scales depends on consumer choices and dietary preferences that are guided by social, cultural, environmental, and traditional factors, as well as income growth. Meat analogues such as imitation meat (from plant products), cultured meat, and insects may help in the transition to more healthy and sustainable diets, although their carbon footprints and acceptability are uncertain. {5.5.2, 5.6.5}

Processed Foods Warnings

In general, vegan and vegetarian diets are considered healthier. However, they can be just as unhealthy as meat-based diets, namely because:

  • It is very easy to fall into unhealthy eating habits on these diets that may be rich in pasta and grains.
  • Of the amount of vegan and vegetarian processed and prepackaged foods coming on the market.
  • We do not know the long-term health effect of imitation meat because of processing.

What to do? Well, go to your local farmers market. As the UN report states, “Attending farmers markets or buying directly from local producers has been shown to change worldviews (Kerton and Sinclair 2010), and food habits towards healthier diets (Pascucci et al. 2011) can be advanced through active learning (Milestad et al. 2010).”

All we are saying is choose wisely no matter what diet you choose and think about the environment.

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