Health & wellness writer at Allin
Nutrition, hydration and healthy habits
Sofia writes approachable, evidence-based wellness content on nutrition, hydration and sustainable healthy habits. She always points readers to qualified professionals for personal medical advice.
Sofia works from public-health guidance and the published reference intakes behind it — the health authority and its advisory body, not a secondary summary of either. Where the evidence is contested she says so, and every article states plainly that general guidance does not replace a professional who knows the reader's own case.
Ranked by how many pages of this site link to them, not by traffic.
· 6 min read
Framingham, SCORE2 and the pooled cohort equations use overlapping but different inputs and were calibrated on different populations, so the same person gets three different percentages. Here is what each one asks for and what the number means.
· 6 min read
Chronological age is exact. Biological age is not one thing but three — epigenetic clocks, blood-marker scores and lifestyle quizzes — and only the first two have published validation. Here is how to tell which one you are looking at.
· 6 min read
WHO puts abdominal obesity at a ratio of 0.90 or more for men and 0.85 or more for women. But measuring in the wrong place changes the answer more than the threshold does — here is exactly where the tape goes.
· 6 min read
FIGO puts a normal cycle at 24 to 38 days; ACOG's older range is 21 to 35. Here is why two respected bodies give different numbers, how much variation is normal, and how cycles change after menarche and before menopause.
· 7 min read
Each parent passes on one ABO allele — A, B or O — and Rh follows a separate gene. Here is every parent combination, which child types it can and cannot produce, and why this is not a paternity test.
· 6 min read
A formula-fed baby takes roughly 2.3 fl oz per pound of body weight per day in the first months, split across the day's feeds. Here is the table by age and weight, why breastfed babies are not measured this way, and the signs that outrank any number.
· 4 min read
An HbA1c of 7 percent corresponds to an average glucose of about 154 mg/dL, or 8.5 mmol/L, or 53 mmol/mol. Here is the whole table, the formulas behind it, and when the number cannot be trusted.
· 5 min read
Set carbs as a fixed gram figure, protein by body weight, and let fat fill what is left. The famous 75 percent fat is an output of that calculation, not an input — and it drops on its own in a deficit.
· 4 min read
Five protocols side by side, what each demands, and the uncomfortable finding from the controlled trials: matched for calories, fasting loses about the same weight as simply eating less.
· 4 min read
The recommended range depends entirely on your BMI before pregnancy: 28 to 40 lb if you started underweight, 11 to 20 lb if you started with obesity. Here is the full table and the weekly rate behind it.
· 5 min read
Add your average cycle length to the first day of your last period. Here is how to measure that length properly, why the estimate has a range rather than a date, and when irregularity is worth a consultation.
· 4 min read
Pregnancy is counted in 40 weeks from your last period, not from conception — so you are already two weeks pregnant at conception. Here is the full calendar, the trimester boundaries and what term actually means.
· 2 min read
The body clears roughly one standard drink per hour. See how long alcohol stays in blood, breath and urine — and why you can't rush it.
· 2 min read
Match your drinking to how much you sweat. Learn to estimate sweat rate and how much to sip per hour during a workout.
· 2 min read
BMI is a quick screen, not a diagnosis. Learn what it misses — muscle, fat distribution, age — and what to check alongside it.
· 2 min read
A pound of body fat holds about 3,500 calories. See where the number comes from, why it's a rough guide, and how to use it for weight loss.
· 2 min read
Growth percentiles compare a child's height and weight to others the same age and sex. Here's how to read them and what really matters.
· 4 min read
Estimate conception from your last period or your due date, understand ovulation timing, and know why the result is a range rather than a single day.
· 3 min read
The 400 mg daily guideline for adults, how much caffeine is in coffee, tea, cola and energy drinks, and why sensitivity varies from person to person.
· 3 min read
Daily fiber targets of 25 to 38 grams by sex and age, why fiber matters for digestion and heart health, and the best food sources to hit your goal.
· 3 min read
The 2,300 mg FDA limit, the 1,500 mg ideal from the AHA, and why most sodium is hidden in packaged food — plus how to read labels and cut back.
· 3 min read
The WHO limit on free sugars, how to turn a percentage of calories into grams, and where hidden sugar comes from — with practical daily targets.
· 3 min read
To turn a step count into distance, multiply your steps by your stride length. Learn how to estimate your stride and convert steps into miles.
· 3 min read
Sleep runs in cycles of about 90 minutes. Waking at the end of a cycle can help you feel more refreshed. Here's how to count back from your wake time.