Health and Wellness Trivia
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146 free Health and Wellness trivia questions with answers — science & nature quiz, new questions added Oct 2026.
52 free Health and Wellness trivia questions with answers. How much of what you know about being healthy is actually true? This wellness quiz sorts the science from the folklore: the 10,000-steps target that began as a Japanese pedometer ad, the eight-glasses-of-water rule nobody can source, the doctor who cracked the knuckles of one hand for fifty years to see what would happen, and the World Health Organization's real numbers on sugar, salt, sleep and exercise. It is built for corporate wellness weeks, HR icebreakers, health-fair booths, nursing and PE classrooms and anyone who likes an argument about coffee. Questions cover nutrition (vitamins, fibre, trans fats, the Mediterranean diet), sleep (REM, the 90-minute cycle, melatonin, the perfect nap length), movement (WHO activity guidelines, BMI's odd origins), stress (cortisol, meditation), skin and hygiene (what SPF actually means, why 20 seconds of handwashing), and longevity (blue zones). Roughly a third are easy warm-ups; the rest will catch out people who read health headlines but not the studies. Every answer is checked against WHO fact sheets, CDC guidance or the relevant Wikipedia entry, and the source line sits under each question so nobody has to take our word for it.
30 of 146 questions with answers and explanations. Play the quiz
Q 01The 10,000-steps-a-day target took off with a 1960s pedometer, the 'ten-thousand step meter', sold in which country?
Japan
Japan's clockmaker Yamasa sold the manpo-kei, or 'ten-thousand step meter', from 1965; the catchy number stuck, though a 2019 Harvard study of older women found the benefit levelling off near 7,500 steps.
Q 02The brain's master body clock sits directly above the crossing point of which nerves?
Optic nerves
Optic nerves cross at the optic chiasm, and the suprachiasmatic nucleus sits just above it in the hypothalamus, so light signals from the eyes reach the clock directly and keep it in step with the day.
Q 03How many minutes of moderate-intensity activity per week does the WHO recommend for adults at minimum?
150
WHO's 2020 guidelines advise at least 150 minutes of moderate activity a week; they also dropped the old rule that exercise only counted in bouts of ten minutes or more, so every short walk now adds up.
Q 04WHO's 2024 study found roughly what share of adults worldwide fall short of recommended activity levels?
31%
About 31% of adults, some 1.8 billion people, were insufficiently active in 2022, the WHO's Lancet Global Health study found; that was up from 23% in 2000 and on course for 35% by 2030.
Q 05How many hours of sleep per night does the National Sleep Foundation recommend for adults aged 18 to 64?
7 to 9
The National Sleep Foundation's 2015 guidance recommends 7 to 9 hours for adults aged 18 to 64; newborns are advised 14 to 17 hours and over-65s 7 to 8.
Q 06A full cycle of non-REM and REM sleep takes, on average, how long?
About 90 minutes
A full non-REM plus REM cycle lasts about 90 minutes and repeats through the night; the REM share grows with each cycle, so most dreaming falls in the hours before waking.
Q 07REM sleep is nicknamed what, since the brain acts awake while the body is paralysed?
Paradoxical
Paradoxical sleep was Michel Jouvet's 1959 name for REM; the paralysis is a safeguard that stops sleepers acting out their dreams, and people in whom it fails can punch and kick their way through them.
Q 08Which hormone, secreted by the pineal gland at night, regulates the sleep-wake cycle?
Melatonin
Melatonin is the pineal hormone that rises in darkness; dermatologist Aaron Lerner isolated it in 1958 from cow pineal glands while hunting for a substance that lightened frog skin.
Q 09The word "circadian" comes from Latin words meaning what?
About a day
Circadian comes from Latin circa diem, 'about a day', coined by Franz Halberg in 1959; in 1729 Jean-Jacques de Mairan showed a mimosa kept its daily leaf rhythm in constant darkness.
Q 10For a 'coffee nap', researchers advise drinking the coffee when?
Just before dozing off
Just before dozing off: caffeine takes about 20 minutes to kick in, so it arrives as a short nap ends, and in driving-simulator tests the pair cut sleepy drivers' errors far more than caffeine alone.
Q 11Whose 1990s study found that pilots who took a 26-minute cockpit nap stayed markedly more alert?
NASA
NASA let long-haul crews take a planned 40-minute cockpit rest; they slept 26 minutes on average and stayed more alert right through descent and landing than crews who flew on without a break.
Q 12Roughly how long does a healthy adult take to clear half a dose of caffeine?
About 5 hours
About 5 hours is typical in healthy adults, within a range of roughly 3 to 7, so half the caffeine in a 4 pm coffee is still circulating at 9 pm and a quarter of it in the small hours.
Q 13Caffeine keeps you awake by blocking receptors for which sleep-promoting molecule?
Adenosine
Q 21Drinking far too much water can dilute blood sodium into a dangerous condition called what?
Hyponatremia
Hyponatremia is dangerously low blood sodium; water intoxication from overdrinking is why US Army guidance caps fluid intake at about 1 to 1.5 litres per hour during heavy sweating.
Q 22Humans must eat which vitamin because the gene for the last enzyme needed to make it is broken?
Vitamin C
Humans cannot make Vitamin C because the GULO gene for the final enzyme is broken; guinea pigs share the defect, which is how two Norwegian doctors stumbled on the first animal model of scurvy in 1907.
Q 23Which naval surgeon showed in 1747 that citrus fruit treats scurvy, in an early controlled clinical trial?
James Lind
Caffeine is an adenosine receptor antagonist: adenosine builds up during waking hours and signals sleepiness, and caffeine's similar shape lets it occupy those receptors without activating them.
Q 14Health Canada advises healthy adults to consume no more than how much caffeine per day?
400 mg
Health Canada's limit for healthy adults is 400 mg of caffeine a day, a level a 2017 systematic review judged safe; just three times that, swallowed at once as pure caffeine powder, can trigger seizures.
Q 15Which of these counts towards the WHO's limit on 'free sugars', alongside table sugar, honey and syrups?
Fruit juice
Fruit juice counts towards the WHO limit of 10% of daily energy, roughly 50 grams of free sugars, but whole fruit and milk do not, because the WHO found no evidence that their sugars do harm.
Q 16The WHO's daily salt limit for adults, 5 grams, comes to roughly how much?
A teaspoon
A teaspoon, or just under, holds the WHO's 5-gram ceiling, which equals 2 grams of sodium; the average adult worldwide eats about 11 grams of salt a day, more than double the limit.
Q 17Which vegetable does the WHO leave out of its 400 g daily fruit-and-vegetable target?
Potatoes
Potatoes are left out, along with other starchy tubers, because they are eaten as the meal's starch in place of bread or rice; Britain's 5 A Day slices the same 400 g into 80-gram portions.
Q 18According to the WHO, no more than what share of total energy should come from trans fat?
1%
WHO caps trans fat at under 1% of total energy, about 2 grams a day; its 2018 REPLACE campaign set out to clear industrial trans fat from the world's food by the end of 2023 and missed the target.
Q 19From June 2018, the US banned which main industrial source of trans fat from food?
Partially hydrogenated oils
The FDA had ruled in 2015 that partially hydrogenated oils were not generally recognised as safe.
Q 20Which hormone, also called ADH, tells the kidneys to reabsorb water when the body is dehydrated?
Vasopressin
Vasopressin, or antidiuretic hormone, is released by the posterior pituitary and makes the kidneys return water to the blood; alcohol suppresses its release, which is why drinking sends people to the toilet so often.
James Lind, aboard HMS Salisbury in 1747, gave pairs of scurvy patients cider, vitriol, vinegar, seawater, a spice paste or oranges and lemons; only the citrus pair recovered quickly.
Q 24Which vitamin is also a hormone that the body can make for itself?
Vitamin D
Vitamin D is made in the skin under the sun's UVB rays, which for most people supplies more than diet does; darker skin makes less of it, because the pigment melanin acts like a shade.
Q 25Which vitamin, found naturally only in animal foods, is built around a single atom of cobalt?
Vitamin B12
Vitamin B12 is built around a single cobalt atom, hence its chemical name cobalamin; working out its structure by X-ray crystallography helped win Dorothy Hodgkin the 1964 Nobel Prize in Chemistry.
Q 26Flaxseed, chia and walnuts supply ALA, the plant form of which family of fats?
Omega-3
Omega-3 in plants comes as alpha-linolenic acid, or ALA, which the body cannot make for itself; it converts only a small share into the EPA and DHA found in oily fish, so those two are best eaten directly.
Q 27Which nutrient is defined as the part of plant food that human digestive enzymes cannot fully break down?
Dietary fibre
Dietary fibre passes through the small intestine undigested; microbes in the large intestine then ferment part of it into short-chain fatty acids, while the rest adds the bulk that keeps the bowel regular.
Q 28Which eating pattern does UNESCO list as Intangible Cultural Heritage?
Mediterranean diet
The Mediterranean diet won its UNESCO listing as a way of life, not a menu: the citation covers harvesting, fishing and cooking, and calls shared meals the foundation of the region's cultural identity.
Q 29The body mass index divides a person's weight by the square of what?
Height
Height squared sits under weight in a formula from the 1830s by Belgian astronomer Adolphe Quetelet; Ancel Keys, who named it the body mass index in 1972, judged it fit for studying populations, not for assessing individuals.
Q 30A body mass index of 30 or more puts an adult in which BMI category?
Obese
Obese begins at a BMI of 30, with overweight from 25; because the index cannot tell muscle from fat, heavily muscled athletes can land in the obese band without carrying excess fat.