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98 free Health and Wellness trivia questions with answers — science & nature quiz, new questions added Aug 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.
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Q 01The famous "10,000 steps a day" target originated where?
A Japanese pedometer marketing campaign
It began as a Japanese pedometer marketing campaign: clockmaker Yamasa sold the manpo-kei, or 'ten-thousand step meter', from 1965, and the round number stuck without any clinical basis.
Q 02Which structure in the hypothalamus acts as the body's master circadian clock?
Suprachiasmatic nucleus
The suprachiasmatic nucleus, a cluster of about 20,000 neurons sitting above the optic chiasm, synchronises the body's circadian rhythms to light signals arriving from the retina.
Q 03How many minutes of moderate aerobic activity per week does the WHO recommend for adults at minimum?
150
WHO's 2020 guidelines advise adults to do at least 150 minutes of moderate aerobic activity a week, or 75 minutes of vigorous activity, plus muscle-strengthening on two or more days.
Q 04WHO's 2024 study found roughly what share of adults worldwide fall short of recommended activity levels?
31%
The answer is 31%: WHO's 2024 study in The Lancet Global Health found about 1.8 billion adults insufficiently active in 2022, while around 80 percent of adolescents fell short.
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 four to six times a night, with more deep sleep early and more REM towards morning.
Q 07REM sleep is nicknamed what, since the brain acts awake while the body is paralysed?
Paradoxical
Michel Jouvet named REM 'paradoxical sleep' in 1959 because the brain's activity resembles waking while muscles are paralysed; Aserinsky and Kleitman had first linked REM to dreaming in 1953.
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 10How long does a "power nap" typically last?
10 to 30 min
A power nap is 10 to 30 minutes: short enough to avoid deep sleep and grogginess. A 1995 NASA study found a brief cockpit nap raised pilots' alertness by 54 percent.
Q 11NASA research found that a nap of what precise length improved pilot alertness by 54 percent?
26 min
The 1995 NASA study led by Mark Rosekind found a 26-minute cockpit nap improved pilots' alertness by 54 percent and performance by 34 percent; longer naps risk sleep inertia.
Q 12In healthy adults, caffeine's half-life is roughly how long?
3 to 7 hours
Caffeine's half-life in healthy adults is about 3 to 7 hours (typically near 5); it roughly doubles in women on oral contraceptives and falls 30 to 50 percent in smokers.
Q 13Caffeine keeps you awake by blocking receptors for which sleep-promoting molecule?
Adenosine
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 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 22Which of these can humans NOT make themselves, because the gene for the final enzyme is broken?
Vitamin C
Humans cannot make Vitamin C because the GULO gene for the final enzyme is broken; guinea pigs and most bats share the defect, which made guinea pigs the classic scurvy lab animal.
Q 23Which naval surgeon showed in 1747 that citrus fruit treats scurvy, in an early controlled clinical trial?
James Lind
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, roughly three 8-oz mugs of brewed coffee; a 2017 systematic review of caffeine toxicology found that intake safe.
Q 15The WHO says free sugars should make up less than what share of total daily energy intake?
10%
WHO's 2015 guideline puts free sugars below 10% of total energy, about 50 grams or 12 level teaspoons a day, adding that going under 5 percent may bring further benefits.
Q 16According to the WHO, adults should limit salt to less than how many grams a day?
5 g
Five grams of salt is about a teaspoon and equates to 2 grams of sodium.
Q 17How many grams of fruit and vegetables a day does the WHO set as a minimum?
400 g
WHO advises at least 400 g of fruit and vegetables a day, excluding starchy roots such as potatoes; that figure is the origin of 'five a day' in roughly 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 and saturated fat at 10%; its 2018 REPLACE initiative aimed to eliminate industrial trans fat by the end of 2023 and fell short.
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 from the posterior pituitary makes the kidneys reabsorb water?
Vasopressin
Vasopressin, also called antidiuretic hormone, is released from the posterior pituitary when the body is dehydrated and makes the kidneys' collecting ducts reabsorb water, concentrating the urine.
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 technically a misnomer, being a secosteroid hormone the skin makes from sunlight?
Vitamin D
For most people skin synthesis under UVB light contributes more than diet; US milk is fortified with it.
Q 25Which nutrient is a coordination complex built around an atom of cobalt?
Vitamin B12
Vitamin B12 is built around a single cobalt atom, hence its chemical name cobalamin; Dorothy Hodgkin worked out its structure by X-ray crystallography in 1956.
Q 26Which omega-3 fatty acid is essential because the body cannot synthesise it?
ALA
ALA, alpha-linolenic acid, is the essential omega-3: animals lack the enzymes to make it and convert only a small fraction into the longer-chain EPA and DHA found in oily fish.
Q 27Which nutrient is defined as the part of plant food that human digestive enzymes cannot fully break down?
Dietary fibre
Dietary fibre is the plant material that resists human digestive enzymes; it comes in soluble forms such as pectin and insoluble forms such as cellulose, and wheat bran is roughly 40 percent fibre.
Q 28In which year did UNESCO inscribe the Mediterranean diet as Intangible Cultural Heritage?
2010
UNESCO inscribed the Mediterranean diet on its Intangible Cultural Heritage list in 2010, nominated by Spain, Greece, Italy and Morocco; Cyprus, Croatia and Portugal were added in 2013.
Q 29Which scientist coined the term 'body mass index' in a 1972 paper?
Ancel Keys
Ancel Keys coined 'body mass index' in a 1972 Journal of Chronic Diseases paper; the underlying weight-over-height-squared ratio was devised in 1832 by Belgian astronomer Adolphe Quetelet.
Q 30A body mass index of 30 or more puts an adult in which BMI category?
Obese
Obese begins at 30; overweight runs from 25 to 29.9 and underweight is anything under 18.5.