Key takeaways • It is one of the nine essential amino acids, and the enzyme phenylalanine hydroxylase converts most of it into tyrosine, which becomes dopamine, noradrenaline, adrenaline and melanin. • The Dietary Reference Intake for phenylalanine plus tyrosine is 27 mg per kg of body weight a day, roughly 1,900 mg for a 70 kg adult. Most people eat far more without trying. • Diet drinks carry a warning because aspartame is about half phenylalanine by weight.

Stuart McGill spent three decades at the University of Waterloo putting spines under load in a laboratory and watching what broke them. His finding reorganised how coaches think about abdominal training: the damage came from repeated bending, not from heavy loads. Which made the sit-up, a movement built entirely from repeated bending, a strange choice for the exercise everyone did a hundred of. His replacement list runs to three exercises, none of which involves curling up of

In 1978 three psychologists tracked down 22 major lottery winners and a group of people recently paralysed in accidents, and asked both how happy they were. The winners were less delighted than anyone expected. The accident victims were far less miserable. That study has been picked apart for forty years, and its sample was small enough to deserve the scrutiny, but the question it raised has not gone away. If winning a fortune and losing the use of your legs both fade towards

A mother leaves a toddler in an unfamiliar room with a stranger, then comes back three minutes later. One child wails while she is gone, then settles within seconds of her return. Another barely reacts to the departure, and when she walks back in he carries on stacking bricks as though nobody had left. In a laboratory in Baltimore in the 1960s, Mary Ainsworth watched that scene play out hundreds of times. What interested her was never the crying. It was the reunion. Key Takea

KEY TAKEAWAYS • Protein shakes are a supplement, not a food group. Whole food protein sources are nutritionally superior • Most people eating a normal diet do not need a protein shake to meet daily requirements • They are genuinely useful when appetite is low, timing is difficult, or food access is limited around training • Quality varies significantly between products. Third party testing is the only reliable check • Total daily protein matters far more t

KEY TAKEAWAYS • Morning routines work when they anchor intention, not when they fill time • Affirmations have mixed evidence: they help people who already feel reasonably good about themselves and can backfire for those who do not • Short, specific and believable statements work better than grand claims • The best morning prompt is a question, not a statement, because questions activate thinking rather than passive repetition • Consistency matters more tha

KEY TAKEAWAYS • Taurine is an amino acid found naturally in meat, fish and dairy, and produced by the body • Energy drinks contain taurine, but the caffeine in them is what drives the effect • Supplement evidence is mixed: reasonable support for exercise recovery, weak for energy and cognition • A 2023 Nature study found taurine decline with ageing in animals, sparking interest in longevity claims. Human evidence remains early • It is well tolerated at stu

KEY TAKEAWAYS • All relationships need active maintenance, not just attention when problems appear • Most relationship conflict is about the process, not the topic. How you disagree matters more than what you disagree about • Criticism attacks the person; a complaint addresses the behaviour. One is manageable, one is corrosive • Repair attempts during conflict are one of the strongest predictors of relationship health • Contempt is the most damaging patter

KEY TAKEAWAYS • Trying to fall asleep is often the problem. Sleep is a passive process that requires reduced arousal, not effort • The 4-7-8 breathing technique reduces physiological arousal and works for many people within minutes • A consistent wake time is the strongest single variable, more than bedtime • The bed should be for sleep and sex only. Using it for other activities trains the brain to be awake there • Lying awake for more than 20 minutes is.

KEY TAKEAWAYS • Glycolic acid is an alpha hydroxy acid that loosens the bonds between dead skin cells • It has the smallest molecule of the AHAs, so it penetrates most easily and irritates most easily • Start at a low concentration, twice a week. Almost all glycolic acid problems come from using too much too soon • It increases sun sensitivity. Daily sunscreen is not optional with it • On deeper skin tones, over exfoliation can trigger dark marks, so gentl

KEY TAKEAWAYS • A dad joke works because of the groan, not despite it • Puns build genuine language skills, since they require holding two meanings of a word at once • A joke of the day is one of the cheapest classroom routines there is • Wordplay is harder for English language learners, so explaining the double meaning is part of the value • Let children tell them, since delivery practice is a speaking skill • Keep them short. The best dad jokes are u

KEY TAKEAWAYS • Most headaches are primary, meaning the headache is the condition rather than a symptom of something else • Tension type headaches are the most common. Migraine is the most disabling • Location and character matter more than severity when working out the type • Painkillers taken more than about 10 to 15 days a month can cause medication overuse headache • A headache diary is the single most useful thing you can do before seeing a doctor •

KEY TAKEAWAYS • One cup of pineapple provides most of an adult's daily vitamin C • Bromelain, its best known compound, is a group of enzymes that digest protein • Bromelain is why pineapple can make your mouth tingle, and why it stops jelly from setting • Most bromelain research uses concentrated supplements, not the amount in a bowl of fruit • Pineapple does not burn fat or detox anything. Those claims have no good evidence • It is fairly high in natu

KEY TAKEAWAYS • L-theanine is an amino acid found almost exclusively in tea leaves • It promotes calm alertness rather than sedation, which is why tea feels different from coffee • The best evidence is for pairing it with caffeine, which improves focus and reduces jitteriness • Studies typically use 100 to 400 mg, most often 200 mg • Effects are felt within 30 to 60 minutes, unusually fast for a supplement • It has a good safety record, with few side e

KEY TAKEAWAYS • 98.6 F (37 C) comes from a study published in 1868. Modern measurements are usually lower • Normal adult temperature ranges roughly from 97 F to 99 F (36.1 C to 37.2 C) • A fever in adults is generally 100.4 F (38 C) or higher • Any fever of 100.4 F (38 C) in a baby under three months needs urgent medical assessment • How unwell someone looks matters more than the exact number • A temperature below 95 F (35 C) is hypothermia and is a me

KEY TAKEAWAYS • Red Dye 40, also called Allura Red AC or E129, is the most widely used food colouring in the world • It is made synthetically from petroleum derived chemicals, not from insects. That is carmine, a different colouring • Allergic type reactions are real but uncommon • The link with hyperactivity in children is contested. The EU requires a warning label, the US does not • In April 2025, US health authorities announced a voluntary phase out of

KEY TAKEAWAYS • Honey packs are single serve sachets marketed as natural energy or performance products • Regulators have repeatedly found undeclared prescription drugs in them, most often sildenafil or tadalafil • The main danger is a severe drop in blood pressure in people who take nitrate medicines for heart conditions • Doses are unknown and vary between batches, so there is no way to know what you are taking • Erectile difficulty can be an early sign

KEY TAKEAWAYS • Ashwagandha is a shrub used in Ayurveda for centuries, now one of the best selling supplements worldwide • The best evidence is for reducing stress and improving sleep, from multiple small, short trials • Most trials use 250 to 600 mg of root extract daily for 8 to 12 weeks • Rare cases of liver injury have been reported, and at least one European country has moved to restrict it • Avoid it in pregnancy, with thyroid or autoimmune condition

KEY TAKEAWAYS • Gout is caused by uric acid crystals forming in a joint, most often the big toe • Most uric acid is made by the body itself, so diet lowers it modestly rather than dramatically • Organ meats, some seafood, beer and sugary drinks are the strongest dietary triggers • Vegetables high in purines do not raise gout risk. Older restriction lists are out of date • Low fat dairy, water, coffee and cherries are associated with lower risk • Losing

KEY TAKEAWAYS • Start at least one month before trying to conceive. The neural tube closes in the first 28 days of pregnancy, often before a pregnancy is known • Folic acid and iron are the two non negotiable ingredients. A product missing either is not doing the core job • Iodine is often missing from prenatal products, and deficiency affects fetal brain development • Avoid high dose vitamin A as retinol. Beta carotene is the safe form • Anaemia affects r