An Ethical Diet: What are the impacts of our food choices?

by Dominik Peters and other contributors.
First written: 11 Nov. 2016. Last updated: 4 Dec. 2017.

{{ showOptionBox ? "⇧" : "⇩" }} Calculation Options

How many {{ long_unit() }} {{ considerElasticity ? "on factory farms does demand for 2000kcal cause" : "on factory farms are required to produce 2,000 calories" }}?

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Fig. 1: To produce a day's worth of calories through animal products, animals need to live on factory farms for up to {{ pretty_round(hours(foods["2000kcal Eggs"]) / 24) }} days ({{ pretty_round(hours(foods["2000kcal Eggs"])) }} {{ long_unit() }}).

Many animal welfare scientists and philosophers think that farm animals have bad lives. This applies to most chickens, pigs, and fishes we eat. In modern industrial farms, animals:

Many people eat fewer animal products to prevent these problems. This page explains which diet changes have the biggest effects.

Some foods are worse for animal welfare than others. For example:

Vegetarian dishes (except eggs and milk) do not require animal factories at all.

Some Example Dishes

How many {{ long_unit() }} {{ considerElasticity ? "on a factory farm does demand for various food products cause" : "did animals have to live on factory farms to produce various food products" }}?

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Fig. 2: Time required to produce common animal products.

Do Your Own Calculations

You can change the assumptions behind all the numbers on this page.

Displayed Animals

Choose which animals should be displayed in diagrams.

When someone is sleeping, they do not experience pain like when they are awake. When this option is active, we ignore hours that farm animals spend sleeping. Note that some animals:
  • sleep longer than others, e.g., pigs sleep more than cows
  • are sleep-deprived so that they grow faster (mainly chickens)
Some animals kept for their meat die before they are slaughtered. This can happen:
  • due to untreated disease or injury
  • if the animal can't walk because of fast growth
  • during transport to the slaughterhouse

The meat of these animals is not sold. However, they still had to live their life in a factory. When this option is active, we proportionally count the lives of these animals when calculating total hours.

This option does not apply to eggs and milk.

Generally, when you buy ten fewer chickens, you will cause farms to produce ten fewer chickens in the future. However, due to supply and demand effects, you might not cause this full effect. You might only cause nine fewer chickens to be farmed. This is because the price for chickens may drop very slightly. This might induce others to buy more chickens.

The size of this effect has been estimated by economists. You can use estimates from:

Some animals may feel pain less intensely than other animals. This could be because:
  • their mental experience may be less rich in general
  • some stimuli are less harmful to them

It is very difficult to estimate how much different animals suffer, compared to each other. One useful proxy may be the size of an animal's brain.

Animals with larger brains may have richer mental experiences, and thus experience pain more intensely. (Certainly, though, brain size is not the only thing that matters.) Brain size can be measured in terms of the number of neurons in the brain. Alternatively, it can be measured by how heavy the brain is; however, some animals have small brains which have many neurons, so brain mass could be a bad measure.

When considering neuron counts, we may think adding extra neurons have decreasing marginal returns. Thus, it makes less of a difference if a large brain gets larger by 1 million neurons than if a small brain gets larger by 1 million neurons. We can formalise this intuition by weighting, e.g., by the square root of the neuron count.

You can weight the numbers by:

Farm conditions differ between types of animals. For example, many people think that the conditions on chicken farms are worse than on cow farms. Brian Tomasik has estimated the relative badness of suffering on different types of farms.