Is Your Diet Plan Bad for the Planet?

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Whenever a female celebrity makes a public appearance looking particularly fit, especially if they're a Kardashian, or they've just had a baby, or are approaching middle age - magazines and blogs predictably track them down to ask the question "what's your weight-loss secret?!" The response is typically some combination of the fad diet du jour - like Atkins, or Paleo - and insane amounts of exercise with a very expensive personal trainer. While the impact of these diets on celebrities' figures is self-evident, the environmental impact of what's on their plates isn't. If all of us in pursuit of #bodygoals were to run out to the grocery store to buy the ingredients we needed to re-create our favorite celebrities' eating habits, what would be the cumulative effect on the planet?

The truth is it's pretty tricky to estimate the environmental impacts of our dietary choices. One of the reasons scientists studying this topic arrive at such different conclusions - e.g., lettuce is as bad as bacon! versus meat is horrible for the planet - is that they're making very different assumptions about the foods involved in each diet studied. The environmental impacts of individual foods vary a ton, and consequently, the results of the studies change drastically depending on the components of the vegetarian or meat-eating diets the scientists are reviewing. The conclusions of these reports are also impacted by how the foods they're studying are measured. For example, conclusions drawn from one 2011 report from the Environmental Working Group on which types of food have the highest greenhouse gas emissions can vary based on whether the food is measured by weight or by calorie produced. Despite all this complexity and uncertainty, one conclusion seems to be undisputable: What you chose to eat has environmental consequences.

So it's important, even when we try to lose weight or get in better shape, to still make good food choices. To help, we've pulled together a list of the latest diet trends, the types of foods each plan encourages you to eat and the environmental impacts of producing those ingredients. While we can't cover every issue related to a diet's sustainability in detail, we hope this information will not only help you choose the diet that sounds the most delicious or will help you achieve your fitness goals the fastest, but could also be the most eco-friendly and lessen your impact on the environment. Our big takeaway after reviewing all this information is this: a plant based diet that incorporates some sustainably produced animal products is by far the least harmful for the planet in terms of water use, greenhouse gas emissions and land use.


What are the Diet's Rules?

There are several different types of vegetarian diets: 1 ) the traditional version made up of fruits, vegetables, grains, beans and nuts; 2 ) The lacto-vegetarian option that includes those plant-based foods as well as dairy and cheese; and 3 ) the lacto-ovo vegetarian diet that contains all of the above, plus eggs.

What Are the Vegetarian Diet's Environmental Impacts?

According to the latest science, the vegetarian diet is by far the most environmentally friendly dieta person can have. Interestingly, recent research published in Elementa has shown that from a land use perspective, even partially omnivorous diets (i.e., some animal products included) like the lacto-vegetarian diet, rank above veganism in terms of sustainability. Also, protein derived from lentils, tofu and dried beans are the most sustainable because they produce some of the lowest greenhouse gas emissions of any food by weight. Therefore, any diet that depends on these foods as their largest source of protein is going to be among the most eco-friendly.

But vegetarians aren't totally off the hook. Those who eat a lot of dairy may be surprised to hear that cheese has the third highest greenhouse gas emissions of any food - almost 30 pounds of CO2 per kilo eaten. 

Tips to Make the Diet More Eco-Friendly

If you're considering going vegetarian, try to buy fresh, locally grown produce and pasture raised dairy and eggs. If you just can't give up your cheese, consider swapping parmesan and cheddar for  locally produced, less dense items like cottage cheese or ricotta which are more eco-friendly because they take less milk to produce.


What are the Diet's Rules?

By definition, vegans can't eat any animal products at all, including meat, poultry, honey, milk, cheese, gelatin, fish or eggs. The staples of the diet are all plant based products, like nuts, seeds, fruits, vegetables, beans, grains and legumes.

What Are the Vegan Diet's Environmental Impacts?

One of the major findings by the advisory committee that wrote the US 2015 Dietary Guidelines regarding sustainable diets was that a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower animal-based foods, is healthier and associated with less environmental impact than the current US meat-centric diet. This is largely due to the fact that, in contrast to meat, few greenhouse gases are emitted in the production of fruits, vegetables and nuts. According to the Environmental Working Group's comprehensive 2011 study, most of plants' greenhouse gas emissions are generated after crops leave the farm (during processing, transport, cooking and waste disposal).For example, cooking beans in a pressure cooker that cuts cooking time in half reduces their emissions by 25 percent. In addition, fruits and vegetables have a much smaller water footprint compared to meat, poultry, dairy and eggs.

Because they have much lower emissions, transportation accounts for a much higher fraction of a vegetable's overall environmental footprint. As a result, buying locally-grown produce can significantly reduce the climate impact of vegetable production(10 to 30 percent), but has a relatively smaller impact for meat (one to three percent). For example, buying locally can reduce the overall footprint for broccoli and tomatoes by as much as 20 percent, while purchasing locally-raised meats reduces meat's carbon footprint by just one to three percent. 

You may be wondering then why the vegan diet doesn't make the top of the list as the most sustainable. According to the recent study in Elementa, when applied to an entire global population, the vegan diet wastes available land that could otherwise be used to feed people, since different kinds of land are best suited for different types of food (i.e., some land is better for animal grazing than raising crops). Also, the vegan diet is made up entirely of annual plants that need to be replaced every year, whereas perennial crops including hay and grain used to feed livestock are alive year round and provide humans with opportunities to produce a lot of food over multiple seasons. Thus the study concludes that if modern agriculture in the US were adjusted to the vegan diet, we'd be able to feed 735 million people, but with a dairy-friendly vegan diet, we could feed 807 million, from a purely land use perspective. 

Tips to Make the Diet More Eco-Friendly

If you're considering going vegan, try to buy organic, fresh, locally grown produce. Just be careful not to let it go to waste! Approximately 40 to 50 percent of food waste in the US happens at home, and the majority of what's thrown out - 28 percent - is fresh fruits and vegetables. In the US, an average family of four wastes about 25 percent of the food they buy, costing them $1,365 to $2,275 per year. So for people who don't eat meat, reducing food waste is the easiest way to reduce greenhouse gas and other environmental impacts of food. Also, be sure to purchase organic soy products as conventionally produced soy is likely to be made from genetically modified crops that have a huge negative impact on the environment.

South Beach

What are the Diet's Rules?

The South Beach Diet is broken into three phases, which become progressively less restrictive as time goes on. The diet focuses on replacing "bad carbs" and "bad fats" with "good carbs" and "good fats." In the first phase, dieters eat lots of lean protein (like seafood, poultry and soy) vegetables, beans, eggs, dairy and nuts. In phase two, dieters reintroduce carbs including whole grain breads and pastas, brown rice and fruit. In the third "maintenance" phase, no foods are restricted, but the dieter is encouraged to eat 3 servings of fruit a day, 3 to 4 starches and no more than 2 tablespoons of good fats like olive oil.

What Are the South Beach Diet's Environmental Impacts?

The South Beach Diet has a larger environmental footprint than vegetarian or vegan diets because it includes red meat, seafood and poultry. However, its impact on the planet is still smaller than other diets on this list that include meat because it still allows eaters to have protein from soy, beans and legumes.  

While many studies have shown that fish have a lower carbon footprint than land animals - making diets that rely on it as a major protein source much more environmentally-friendly - sources of greenhouse gases are different for farmed and wild fish. For example, the primary source of emissions from farmed salmon come from the food they eat, while diesel combustion from fishing boats accounts for most of the emissions from wild-caught fish. Overall, according to the Environmental Working Group and research published in the American Journal of Clinical Nutrition, canned tuna and other wild caught fish have lower emissions than open-water farmed fish. This is partially due to the fact that wild-caught fish live on food that they consume directly from the ocean, in contrast to open-water farmed fish that are fed energy-intensive feed (such as sardines, menhaden, soybean meal and wheat) that must be grown and/or caught. However, the higher the proportion of plant sources in a farmed fish's diet, the lower the emissions.

But the problem with fish is much bigger than the carbon footprint associated with farming or catching it. Wild fish stocks for the most popular seafood - like bluefin tuna and Atlantic cod - are in serious danger of collapsing completely largely due to overfishing and illegal fishing.

Tips to Make the Diet More Eco-Friendly

You don't have to go totally meat-free to reduce your impact on the environment. By replacing 70 percent of your beef consumption with other meats or legumes, which the South Beach diet lets you do, research has shown that people can successfully reduce their land use and greenhouse gas emissions by 35 percent. Also, try sticking to sustainable US-caught wild seafoods recommended by the Monterey Bay Aquarium's Seafood Guide (or fish raised in recirculating farms), and pasture-raised local poultry. Just be careful not to waste any seafood you buy. Studies show that American consumers throw away close to 50 percent (!) of the fresh and frozen seafood they purchase.


What are the Diet's Rules?

The Atkins Dietis the original high protein, low carb weight loss plan. People on the Atkins diet are required to eat lots of meat, poultry, seafood, eggs, green vegetables, full fat dairy, seed, nuts and oils. For the first phase, dieters are also told to avoid all sugars, grains, high carb root vegetables, starches like potatoes, high carb fruits like bananas, and legumes. Eventually, as people reach their weight loss goals, they are allowed to include some starches, legumes and fruits back into their diet.

What Are the Atkins Diet's Environmental Impacts?

Study after study shows that one of the worst things you can do for the planet is eat a lot of red meat. Not only do dairy and red meat have the highest greenhouse gas emissions per kilogram of eaten food, they have the highest water footprints. And including a lot of dairy into your diet, as the Atkins plan recommends, only widens your environmental footprint. Dairy production significantly impacts the environment in a variety of ways, but the size of the impact is largely dependent on how the dairy cows are raised. Conventionally-raised (i.e., factory farmed) dairy cows and their manure produce greenhouse gas emissions that contribute to climate change and pollute local water resources. Conventional dairy farming and the large amounts of industrially farmed genetically modified corn used to feed cows can also damage environmentally important areas, such as prairies, wetlands and forests. What's more, dairy production requires a significant amount of water, and as a result, cheese has one of the largest water footprints of any food.

Tips to Make the Diet More Eco-Friendly

One good thing about the Atkins diet is that it eventually allows you to re-incorporate starches and legumes into your diet. Once you reach that phase, try swapping out some of your beef meals with veggie based proteins and make sure that the majority of your meals throughout the program are made up of fresh, local, seasonal produce. And be sure to choose pasture-raised meat, poultry and dairy to make your environmental footprint smaller.


What are the Diet's Rules?

The founders of the Paleo Diet explain that the eating plan was developed to re-create the way early humans ate while we were pre-agricultural hunter-gatherers. On the plan, dieters are required to eat lots of grass-fed meat and poultry, seafood, fresh fruits and vegetables, eggs, nuts, seeds and healthy oils (olive, coconut, flaxseed, macadamia and avocado). Dieters are forbidden from eating any grains, legumes, dairy, refined sugar, potatoes, processed foods, salt or refined vegetable oils.

What Are the Paleo Diet's Environmental Impacts?

As we mentioned above, any diet that relies heavily on meat is a bad idea, environmentally speaking. However, well-managed grazing and grass-fed meat operations that the Paleo Diet encourages people to buy from are far better for the environment than conventionally-raised meat. Research from the Union of Concerned Scientists shows that raising cows on pasture helps to conserve soil, reduce erosion and water pollution, increase carbon sequestration and preserve biodiversity and wildlife.

Tips to Make the Diet More Eco-Friendly

If you're tempted to go Paleo, eat locally-raised and grass-fed meat and poultry, pasture-raised eggs, wild-caught sustainable seafoodfrom the US and locally-grown produce. Also, pack your plates with all the fruits and veggies you can.

Whole 30

What are the Diet's Rules?

The goal of the Whole 30 Diet is to eliminate a person's unhealthy eating patterns and provide them with what the founders call a "nutritional reset." The program is very restrictive and only lasts 30 days. During that time, dieters aren't allowed to have any of the following: sugar (even artificial), alcohol, grains, legumes, beans or dairy. People on the Whole 30 plan aren't even allowed to have fake healthy versions of their favorite sweet treats, even if those treats are made up of ingredients that are compliant with the diet. What's left is a diet made up of meat, poultry, seafood, eggs, fruit, nuts and vegetables.

What Are the Whole 30 Diet's Environmental Impacts?

The Whole 30 diet by far has the most significant negative environmental impacts of any diet on this list because it encourages people to eat a diet made up mostly of animal-based protein, eggs, and seafood. It also fails to address how those meats are raised or encourage people to buy sustainably-produced poultry and eggs. And without the ability to swap out any meat or seafood for grains or beans, dieters on this plan are likely to eat meat at almost every meal.

Conventional red meat production has significant environmental ramifications due to the enormous amounts of grain, land and water needed to feed the animals and the incredible amount of amount of waste and methane they generate. Lamb by far has the greatest environmental impact, generating more greenhouses gases per kilo than beef partly because the animals produce less edible meat relative to their weight as live animals. Beef produces the second highest amount of greenhouse gas emissions per kilo- more than twice that of pork, four times as much as chicken, and more than thirteen times higher than plant derived proteins like tofu and lentils. Six studies cited by the committee that developed the Dietary Guidelines for Americans last year suggested that eating less meat is better for the environment.

Relying so heavily on nuts can take a big toll on the environment as well. Research has shown that commercial production of coconuts, almonds, walnuts and pistachios can have harmful impacts on the environment due to these crops' high water usage and effects on their surrounding eco-systems. However, some nut production is actually good for the environment! These include nitrogen fixing- soil enhancing peanuts, locally-grown pecans from Southern states in the US, easy-to-grow hazelnuts and brazil nuts whose production actuallysupportsthe Amazon rainforest.

Tips to Make the Diet More Eco-Friendly

It's pretty difficult to make this meat-heavy diet plan eco-friendly, but if you're still committed to trying it, try to make it similar to the Paleo diet by focusing on grass-fed and pastured meats, poultry, dairy and eggs and US-caught wild seafood. And, as always, eat lots of locally grown, seasonal fruits and veggies.