Our dietary choices affect our lives on several levels. The question which arises most often is probably, “What is best for our health?” After that, many of us want to minimise the pain and suffering we cause, to follow the dictates of our religion and to minimise our negative impact on the environment. Are these goals compatible? If so, to what extent? And what is the optimum diet for ourselves, for other living creatures, and for the planet?
To answer these questions, we might begin by defining the four broad categories of diet which most of us recognise, and mentioning some of their variants.
1. Vegan
Veganism is often considered a lifestyle strongly anchored in animal rights, rather than just a diet. The Vegan Society defines it as, “A philosophy and way of living which seeks to exclude – as far as is possible and practicable – all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose … In dietary terms it denotes the practice of dispensing with all products derived wholly or partly from animals.”
Sub-categories and related diets
- Fruitarian: restricted to fruits, seeds and nuts.
2. Vegetarian
According to the Vegetarian Society, “A vegetarian is someone who lives on a diet of grains, pulses, legumes, nuts, seeds, vegetables, fruits, fungi, … and/or other non-animal-based foods (e.g. salt) with, or without, dairy products, honey and/or eggs. A vegetarian does not eat foods that consist of … any part of the body of a living or dead animal. This includes meat, poultry, fish, shellfish, insects [and] by-products of slaughter (e.g. gelatine).”
Sub-categories and related diets
- Lacto-vegetarian: includes dairy products in a vegetarian diet
- Lacto-ovo vegetarian: includes dairy and eggs
- Jain diet: lacto-vegetarian but excludes onions, garlic and potatoes; the primary motivation is ethical, as it is in veganism.
3. Semi-vegetarian
Semi-vegetarians consume small quantities of meat, fish, eggs, milk and similar products within a largely vegetarian diet. It is likely that most people who call themselves “vegetarian” are technically “semi-vegetarian”, just because it is so difficult to avoid all animal products.
Sub-categories and related diets
- Flexitarian: same as semi-vegetarian.
- Pesco-vegetarian: adds fish, but not other meats, to the vegetarian diet.
- Hindu and Sikh traditions are semi-vegetarian.
4. Omnivore
Omnivores eat (almost) everything.
Sub-categories and related diets
- Mediterranean diet: high consumption of olive oil, legumes, unrefined cereals, fruits and vegetables; moderate to high consumption of fish; moderate consumption of dairy products (mostly as cheese and yogurt) and wine; low consumption of meats other than fish. (More detail on Wikipedia)
- Paleo diet: avoids processed foods, cultivated grains, etc; see Wikipedia: Paleolithic diet for more.
- Muslim (halal): no alcohol, no pork, and other meat must comply with certain conditions.
- Jewish (kosher): no pork, and many other partial or total restrictions.
Variations
Cutting across these four categories we have three more choices:
- Locavores eat primarily local food, usually for social and environmental reasons; see Wikipedia: Local food.
- The organic food movement (Wikipedia: Organic food) began with the intention of promoting sustainable farming practices but consumers favour it for (perceived) health benefits.
- There is also a small raw-food sub-group of each of the larger divisions – Raw Vegan, Raw Paleo, etc. The ethical and environmental implications of each must clearly be the same as for the non-raw equivalent, so the motivation is all about health. Proponents, obviously, claim advantages but the scientific community doesn’t see many; further exploration could start with Wikipedia’s Raw foodism.
One may therefore be a semi-vegetarian locavore, or a raw-food pesco-vegetarian (sashimi might be important to the latter).
Pros and cons
In all these categories …
- Fresh and local is (usually) better for both the planet and our health, and food that is both fresh and local is automatically seasonal.
- Non-local may not be worse for our health but is usually worse for the environment because of environmental costs of transport, etc – look up “food miles”.
- Non-fresh foods may be worse for the planet (e.g. the CO2 cost of refrigerating frozen peas between production and consumption), our health (e.g. over-processed foods full of preservatives, salt, sugar and fats) or both.
- “Industrial” models of food production (feedlot cattle, monoculture cropping, etc) are generally worse for the environment than small-scale mixed farming. If their produce is also worse for our health, it’s because many such producers over-use fertilisers, pesticides, growth hormones, etc.
- Organic food production avoids most of the worst effects of industrial farming as per FAO’s Organic agriculture, environment and food security but small-scale mixed farming also avoids most of them whether it’s organic or not.
- Wastage of food is bad for the environment (Paul Hawken says it’s where we can make the biggest impact by changing the way we eat) but doesn’t directly affect our health.
- Over-packaged foods (and especially plastic packaging) are always worse for the environment but are not necessarily worse for our health.
- Too much meat, especially from ruminants, is bad for both our health and the environment, although our grassland-fed beef is far less harmful to the environment than the US feedlot production which most discussions are based upon (for more on this, see The environmental cost of meat).
- Every mouthful we eat comes from once-living plants or animals, so any discussion of harm to living creatures must start with minimising harm, because we can never eliminate it. We can see a nearly-universal sliding scale of perceived harm, from eating only fruit (therefore not even killing the source plant), to eating all sorts of plants, to including animal products which don’t involve killing animals but do involve their exploitation, to adding meat.
- Many religions have rules which strive to minimise the suffering of animals at the time of slaughter.
The triple bottom line
Ethical investors talk about a ‘triple bottom line’ – investments which are good for the environment, good for people and good for profit. The equivalent ‘triple bottom line’ diet is one which minimises harm to the environment and to animals while maximising benefits to our health. There is no logically necessary connection between the three objectives but there is a ‘sweet spot’ where all three happen to coincide: a plant-based diet emphasising fresh, local, seasonal food.
Including some animal products in such a diet will not make it significantly worse for the environment, so avoiding them entirely becomes an ethical choice based only on avoiding exploiting or harming animals. And it is possible to design a healthy diet with almost any combination of foods, so long as it includes a reasonable variety of fresh food, so the desire for a healthy diet is compatible with any ethical choices one might wish to make.
On the other hand, there are risks to health, social well-being and sanity in pursuing any diet too strictly. The Psychology of Idealistic Diets on the Beyond Veg site covers most of them (quite entertainingly, too), but most of us have already seen examples ourselves: the friend who goes hungry in a restaurant, the friend who adopts a strict but unbalanced diet and ends up malnourished, etc.
We should remember, too, that doing our best for the planet is not just about what food we eat but about how far we travel to get it, how many lights we leave on around the house, how often we ride a bike, and so on. As always, balance is important.
Here is an Australian study which assesses the carbon footprints of various common foods.
RMIT’s Karli Verghese and Enda Crossin, working with Lancaster’s Stephen Clune, identified a clear greenhouse gas emissions hierarchy emerging across food categories.
Grains, fruit and vegetables were found to have the lowest impact, followed by nuts and pulses. Chicken, pork and fish had a medium impact, while meat from beef and lamb (ruminant animals with multiple guts) had the highest impact. None of this is surprising, but the size of the differences is enough to raise a few eyebrows: about 50 g of beef or lamb has roughly the same greenhouse impact as 250 – 300 g of chicken, salmon or kangaroo and 1000 – 5000 g of fruit or vegetables.
Here’s a similar set of recommendations from Michalis Hadjikakou of Deakin University on The Conversation – Sustainable shopping: want to eat healthy? Try an eco-friendly diet
Another study assessing environmental implications of our diet is reported here – http://www.abc.net.au/news/science/2018-06-01/would-you-go-vegan-to-save-the-planet-study-says-its-best-option/9816168 – and finds that veganism is best for the planet but that there are, “huge variations in impact within the same crops and livestock. For instance, the worst 10 per cent of beef production produces 12 times more greenhouse gas and requires 50 times more land to produce 100 grams of protein, compared to the best 10 per cent of beef production. The trend was the same among the major crops — wheat, maize, and rice. The best growing practices achieved the same yield with about a third of the impact.” However, “they found that if they removed the worst 50 per cent of those meat producers, and replaced them with vegetable crops, we’d get a long way toward achieving the benefits of vegan world, without the associated anaemia risk. Yes, we’d have to cut our meat consumption by about half. But given that Australia is among the top meat-eating countries in the world, this sounds like a manageable compromise.”
Most of us don’t see the connection between the animal in the field and the meat on our plate, and we might change our minds about the ethics of meat-eating if we did see it. Butchering livestock on site for the customer must reduce the disconnection as well as minimise the suffering of the the animal.
It’s now official: a new IPCC climate change report calls for urgent overhaul of food production and land management, saying, “Balanced diets featuring plant-based foods such as those based on coarse grains, legumes, fruits and vegetable, nuts and seeds and animal-sourced food produced in resilient, sustainable and low-greenhouse-gas-emission systems present major opportunities for adaptation and mitigation while generating significant co-benefits in terms of human health.”
More at https://www.abc.net.au/news/science/2019-08-08/ipcc-report-climate-change-land-use/11391180
And again:
https://www.theguardian.com/environment/2024/mar/27/flexitarian-diets-global-warming-climate-change
Why do people hate vegans so much?
https://www.theguardian.com/lifeandstyle/2019/oct/25/why-do-people-hate-vegans
What the world eats, a National Geographic project, offers all sorts of insights into diet via interactive pie charts at https://www.nationalgeographic.com/what-the-world-eats/
My own follow-up article, Moving towards a plant-based diet – https://malcolmtattersall.com.au/wp/2019/12/towards-a-sustainable-diet/
Really thorough coverage of the issues on Our World In Data – https://ourworldindata.org/environmental-impacts-of-food
And another aspect, how much fossil fuel is used to produce our food. https://www.overshootday.org/food-and-fossil-fuels/
Thought for the day: We’ve always known, I think, that we can’t live without killing something that was recently (chicken or carrot) or potentially (eggs, seeds) alive. Once we acknowledge that, all the hand-wringing debate over ethical diets reduces to, “Where do we choose to draw the line?”
If we’re going to keep on eating meat, perhaps we should be eating (farmed) python meat: “Python snake meat could be a super protein on dinner plates in years to come, research suggests. A study published in the Nature journal has found the meat to be highly efficient, environmentally friendly source of nutrition that can be raised on waste proteins.” https://www.abc.net.au/news/2024-03-19/python-snake-meat-efficient-source-of-protein-study-finds/103603328
George Monbiot argues for “new protein” (lab-grown meat and meat-substitutes) at https://www.theguardian.com/commentisfree/article/2024/aug/21/livestock-lobby-lab-grown-meat-new-proteins and likens the livestock industry’s opposition to car-makers’ opposition to EVs.