Interactive · 10 questions

Myth-busting quiz

Test what you know about plant-based diets, factory farming, and the planet. Every answer cites its source.

Question 1 of 10

Do you need to eat animal protein to be strong and healthy?

Key takeaways

  • Most 'well-known' facts about plant-based eating (protein deficiency, weak bones, expensive food, ancestral meat) don't survive the peer-reviewed data.
  • Testing yourself is faster than reading — quizzes surface exactly which myths you still carry.
  • Every claim on this page is sourced back to the primary study, dataset or institution.

Share this page

Share on XShare on FacebookShare on WhatsApp

Frequently asked questions

No. Legumes, tofu, tempeh, seitan, whole grains, nuts and seeds cover daily needs easily. The average person in wealthy countries eats roughly double the protein required.

Keep reading

Behind the questions

What the quiz is actually testing

Every question here exists because the same handful of misconceptions come up in almost every conversation about eating animals. This section unpacks the evidence behind the answers, so the quiz is a starting point rather than a scoreboard.

Why myths about diet survive so well

Food beliefs are formed early, reinforced daily by family habit and marketing, and rarely tested against data. Industry communication also plays a measurable role: dairy and meat marketing boards spend hundreds of millions each year on nutrition messaging, and much of the imagery used — open pasture, small barns, a single farmer with a handful of animals — describes a production system that supplies a tiny fraction of what people actually buy. When the picture in your head and the picture in the supply chain diverge that far, ordinary intuition stops being a reliable guide.

Protein is the most common sticking point

Adults need roughly 0.8–1.0 g of protein per kilogram of body weight per day, and more if they train hard — around 1.4–2.0 g/kg. A cup of cooked lentils supplies about 18 g, 150 g of firm tofu about 17 g, 100 g of seitan about 25 g, and a bowl of oats with soy milk around 15 g. Reaching 60–120 g a day from plants is arithmetic, not athletic feat. Where plant-based eaters do need to pay attention is variety and total calories: protein needs are easy to miss on a diet built mostly on fruit, salad and refined starch, regardless of whether animals are involved.

Scale is the hardest thing to intuit

Roughly 80 billion land animals and between one and three trillion fish are killed for food each year. Numbers at that scale stop feeling like quantities and start feeling like weather. One useful anchor: the average person eating a Western omnivorous diet is responsible for around 25–30 land animals a year, and many times that in aquatic animals. Another: livestock and their feed occupy about 77% of global farmland while supplying roughly 18% of calories. Both facts are boring on paper and decisive in practice.

Getting an answer wrong is the useful part

The questions people miss most often are the ones about water footprints, feed conversion and the share of soy grown for animals rather than humans — precisely the areas where public debate has the causal arrow pointing backwards. If you missed those, the linked sources are worth ten minutes; they change how supermarket shelves look.

The claims behind each answer

Figures are global averages; regional numbers vary widely.

ClaimCommon beliefBest available evidence
Protein adequacyAnimal protein is requiredWell-planned plant-based diets are adequate at every life stage
Factory farmingA minority of production~99% of US and ~90% of global farmed land animals
Amazon deforestationDriven by soy for tofu~80% of cleared land becomes cattle pasture; most soy is feed
Water footprint of beef~500–3,000 L per kg~15,400 L per kg, mostly to grow feed
Farmland useRoughly proportional to calories77% of farmland, ~18% of calories
Emissions from foodTransport dominatesProduction dominates; transport is ~6% of food emissions

Poore & Nemecek (Science, 2018) · FAO · Water Footprint Network · Our World in Data

How to use your result

A score is only interesting if it changes what happens after you close the tab.

  1. 1

    Note the two you got wrong

    Those are the beliefs doing the most work in your current food decisions. Read the source attached to each of them before anything else.

  2. 2

    Check one claim independently

    Pick a number that surprised you and look it up in a primary source — FAO, Our World in Data, a national dietetic association. Verifying one figure yourself is worth more than accepting ten.

  3. 3

    Translate it into a swap

    Turn a single corrected belief into one recurring change: the milk in your coffee, the mince in your weekly pasta, the chicken in your lunch.

  4. 4

    Re-take it in a month

    Retention is poor after a single read. A second pass, after you have used the information in a shop, is what makes it stick.

Reading evidence well

Worth doing

  • Prefer meta-analyses and large cohort studies over single trials.
  • Check who funded a nutrition study before weighing its conclusion.
  • Separate questions of health, environment and ethics — they have different evidence bases.
  • Look for absolute risk, not just relative risk, in health headlines.

Worth avoiding

  • Treating a single anecdote — yours or anyone else's — as a population result.
  • Assuming local or organic automatically means low-impact.
  • Confusing correlation in observational studies with proven cause.
  • Dismissing an inconvenient finding because of the source's politics.

Questions about the quiz

Where do the answers come from?

Each question cites its source directly under the explanation. The core references are Poore & Nemecek's 2018 global food-systems dataset, FAO production statistics, Our World in Data's food pages, and position papers from national dietetic associations.

Is the quiz trying to convince me of something?

It is trying to correct factual beliefs, which is not the same as prescribing a diet. Two people can agree on every number here and still make different choices; that is a legitimate outcome.

Why are the numbers global rather than for my country?

Global averages keep the questions comparable across the 33 languages this site is published in. Where your national figures differ significantly — grass-fed systems in Ireland, for instance — the direction of the comparison usually survives even when the magnitude changes.

I scored badly. Does that mean I was misinformed on purpose?

Almost certainly not. Most of these misconceptions are ambient rather than deliberate — they come from packaging, school materials and decades of marketing rather than from anyone lying to you personally.

Can I use the quiz with a class or group?

Yes. It works well as a ten-minute opener before a discussion; the source lines give a teacher or facilitator somewhere concrete to go when a claim is challenged.

Sources

  • Poore, J. & Nemecek, T. (2018). Reducing food's environmental impacts through producers and consumers. Science.
  • FAO (2023). World Food and Agriculture — Statistical Yearbook.
  • Academy of Nutrition and Dietetics (2016). Position paper on vegetarian diets.
  • Mekonnen & Hoekstra (2012). A global assessment of the water footprint of farm animal products.