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body better.
Evidence-based guides on fitness, nutrition, and understanding health metrics.
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Your Due Date Is a Distribution, Not a Deadline
Running, Cycling, Swimming: Why Body Weight Matters Differently
Body weight roughly doubles your running burn but barely changes flat cycling. Here's why weight-bearing and supported activities scale so differently — and where METs fail.
Why 300 Calories of Soup Beats 300 Calories of Crisps
Two 300-calorie lunches can leave you full or starving. Energy density explains why the same calorie target feels effortless with some foods and impossible with others.
Your Activity Multiplier Is a Bigger Guess Than Your BMR
BMR formulas land within about 10% for most people. The activity multiplier you pick afterwards can swing your daily total by 800 calories. Here's where energy actually goes.
The Relative Age Effect: Why Birth Month Shapes School and Sport
Children born just after a school or sport cutoff date are up to a year older than their classmates. That gap shapes selection, confidence, and outcomes for years.
Why Kidney Stone Patients Should Not Restrict Calcium — Stone Formation Chemistry, Urine Concentration, and the 2-Litre Target
Approximately 50% of kidney stone patients have a recurrence within 5 years — and inadequate hydration is the single most modifiable risk factor, because concentrated urine allows crystals to nucleate before being flushed out. Here's the stone formation chemistry for each type (calcium oxalate, uric acid, struvite, cystine), why restricting dietary calcium actually increases oxalate stone risk, why 2 litres of urine output requires approximately 3 litres of fluid intake, and why lemon juice increases urinary citrate as a validated dietary intervention.
The Obesity Paradox: Why the BMI Mortality Curve Is U-Shaped
Some large studies find the lowest mortality in the "overweight" BMI band. The explanation is mostly confounding and reverse causation — here's how to read those findings.
The Scale Hasn't Moved in Six Weeks — Reading Recomposition
A flat scale weight can hide meaningful changes in body composition. Here's which measurements actually reveal recomposition and how to interpret them over time.
The Hidden Variable in Step Counting — How NEAT Variation of 2,000 kcal/Day Dwarfs What Most Exercise Burns
NEAT (Non-Exercise Activity Thermogenesis) — calories burned through all movement that isn't formal exercise — varies by up to 2,000 kcal/day between people of similar size, a larger range than most people's structured workouts. Here's why increasing exercise sometimes doesn't increase total daily calorie burn (NEAT compensation), the metabolically optimal walking speed, why fit people burn fewer calories per step than unfit people of the same weight, and why spreading steps organically through the day may produce more net calorie burn than a single deliberate walk.
Why Caffeine Causes a Crash — Adenosine, the Two-Process Sleep Model, and the Science of Strategic Napping
Caffeine blocks adenosine receptors but doesn't clear the accumulated adenosine — when it's metabolised, adenosine floods the now-unblocked receptors, causing a crash proportional to the sleep debt built up while caffeine was present. Here's the two-process model of sleep (adenosine pressure plus the circadian clock), how the SCN's 24-hour molecular oscillation works, why SWS rebound is prioritised over REM in recovery sleep, and the biomechanics behind the "nappuccino" being more effective than either caffeine or napping alone.
Fibre Is a Carbohydrate That Doesn't Behave Like One — Gut Bacteria, Short-Chain Fatty Acids, and the Net Carbs Calculation
Dietary fibre is technically a carbohydrate but produces only 0-2 kcal/g instead of the 4 kcal/g that macro calculators assume — because human enzymes can't digest it. Here's how gut bacteria ferment soluble fibre into butyrate, propionate, and acetate (the SCFAs that maintain colon health and signal appetite to the brain), why Western adults eat only 15-19g daily against a 25-38g recommendation, and the net carbs calculation for keto tracking.
The Devine Ideal Weight Formula Came From a Drug Dosing Paper — Here's What Actual Health Outcomes Research Shows Instead
The Devine ideal weight formula appeared in a 1974 drug dosing paper — it was never derived from health outcome research. Here's where each major formula came from (insurance actuarial tables, drug pharmacokinetics, military studies), what mortality outcome data actually shows about "healthy" weight (lowest mortality at BMI 22-25 but the curve is flat 20-27), and why the obesity paradox in clinical populations complicates the "lower is healthier" framing.
Dutch Men Grew 18 cm Taller in 130 Years Without Changing Genes — The Secular Height Trend Explained
Dutch men grew 18 cm taller in 130 years — genetics don't change that fast, so the entire increase came from nutrition and disease improvements. North and South Koreans are genetically identical but differ by ~9 cm in average height from 50 years of divergent nutrition. Here's the secular height trend, why "80% heritable" doesn't mean what people think it means, and why contemporary height differences between populations are mostly environmental history, not genetics.
