Blog

Real guides. No fluff.

Evidence-based writing on weight loss, fitness, nutrition, body composition, sleep, blood-work, and AI health.

Weight Loss

How Many Calories Should You Eat to Lose 1 kg in a Week?

The exact calorie deficit to lose 1 kg per week — including a sustainable cap, how to calculate yours, and why most apps get it wrong.

7 min read →
Calculators

How to Calculate Your BMR (Basal Metabolic Rate) — With Examples

BMR is the calories your body burns at complete rest. Here's the Mifflin-St Jeor formula, examples for different ages and weights, and how Zafit uses it.

5 min read →
Calculators

TDEE Explained: How Many Calories You Actually Burn in a Day

Total Daily Energy Expenditure (TDEE) is the calorie target that matters. Here's how to calculate it, the activity multiplier table, and why most people overestimate.

6 min read →
Comparison

Best AI Fitness Apps in 2026 — Honest Comparison

Comparing the top AI fitness apps in 2026 — features, pricing, privacy, and which one is actually worth your time.

8 min read →
Body Composition

How to Measure Body Fat Percentage at Home (4 Methods Compared)

DEXA, calipers, smart scales, AI body scans — the 4 ways to measure body fat at home, with accuracy and cost.

7 min read →
AI Features

How AI Body Scans Work — Phone Camera Body Composition Explained

Computer vision models can estimate body fat % from 2 phone photos. Here's how they work, accuracy, and the privacy story.

6 min read →
Nutrition

Intermittent Fasting for Weight Loss: 16/8 vs 18/6 vs 20/4

The three most popular intermittent fasting protocols, what the evidence actually says, and how to pick the right one for you.

8 min read →
Weight Loss

The Science of Sustainable Weight Loss (Why Most Diets Fail)

Why 80% of weight-loss diets fail within 2 years, what the long-term studies actually show, and the 5 levers that make weight loss stick.

9 min read →
Comparison

AI Meal Scanners vs MyFitnessPal: Which Is More Accurate in 2026?

Photo-based AI calorie counters now rival MyFitnessPal's database for accuracy — and they're 10× faster. Side-by-side test.

6 min read →
Training

Push/Pull/Legs vs Upper/Lower vs Full-Body: Which Split Is Best?

Comparing the three most popular training splits — which is best for muscle gain, weight loss, and your schedule.

8 min read →
Recovery

Sleep Tracking 101: HRV, REM, Recovery Scores Decoded

What HRV actually means, why deep sleep matters more than total sleep, and how recovery scores work — in plain English.

7 min read →
Bloodwork

5 Blood-Work Markers Every Adult Should Know (And What Yours Mean)

Vitamin D, ferritin, HbA1c, TSH, lipid panel — the 5 lab markers that catch the most preventable conditions early.

8 min read →
Skin Health

AI Skin Analysis: What It Can — and Can't — Tell You

How AI skin analysis works, what metrics are reliable, and when to see a dermatologist instead.

5 min read →
Telehealth

AI Voice Doctors: Are They Safe? When to Use Them, When Not To

Voice consults with AI specialists are now sub-second. Here's what they're good for, what they aren't, and how to use them safely.

6 min read →
Nutrition

Calorie Counting vs Intuitive Eating: Which Works for Weight Loss?

When to count calories, when to stop, and how to transition from tracking to intuitive eating without regaining weight.

7 min read →
Supplements

The Only 5 Supplements With Strong Evidence (and Who Should Take Them)

The supplement industry is a $150B mess. These 5 supplements actually have strong evidence — and when (and when not) to take them.

7 min read →
Women's Health

PCOS and Weight Loss: A Practical Nutrition + Training Guide

Why PCOS makes weight loss harder, what actually works (insulin sensitivity is the lever), and a sustainable plan.

8 min read →
Women's Health

Cycle Syncing Your Workouts: What the Research Actually Says

Cycle syncing is everywhere on TikTok. Here's what's evidence-based, what isn't, and a practical training framework.

6 min read →
Mental Health

PHQ-9 and GAD-7 Explained: The 2 Mental Health Screeners Everyone Should Know

PHQ-9 (depression) and GAD-7 (anxiety) are 5-minute self-assessments your doctor uses. Here's how to score yours and what the numbers mean.

5 min read →
Strategy

Why One Health App Beats Fifteen (The Case for a Unified Stack)

The average person uses 12+ health apps. None of them talk to each other. Here's why that's broken and what a unified stack actually delivers.

5 min read →
Comparison

Zafit AI vs Whoop: Better Than a $239/yr Wearable in 2026?

Whoop charges $239/year and locks you into a strap. Zafit delivers recovery, strain, HRV and sleep on the phone you already own. Honest 2026 comparison.

9 min read →
Comparison

Zafit AI vs Oura Ring: AI Health Without a $300 Ring

Oura needs a $300+ ring plus a $5.99/month subscription. Zafit gives you sleep, readiness and HRV on the phone you already own. Full 2026 comparison.

9 min read →
Comparison

Zafit AI vs Apple Fitness+: Beyond Workout Videos

Apple Fitness+ is $9.99/month for workout videos and an Apple ecosystem lock-in. Zafit AI is a full health intelligence platform. Honest 2026 comparison.

8 min read →
Comparison

Zafit AI vs Cal AI: The Indian Alternative That Does More

Cal AI scans calories. Zafit AI scans calories plus body composition, blood-work, skin and recovery — with Indian food, Hindi and Tamil support, free tier.

8 min read →
Comparison

Zafit AI vs Noom: Stop Paying $70/mo for Psychology Lessons

Noom charges up to $70/month for daily psychology lessons and manual food logging. Zafit AI delivers an adaptive plan with AI doing the work — free to start.

9 min read →
Comparison

Zafit AI vs Fitbit Premium: No Bracelet Required

Fitbit Premium needs a $100+ bracelet plus $9.99/month and locks your data inside Google. Zafit AI runs on your phone, free to start. Honest 2026 comparison.

8 min read →