Clinically Reviewed

Health Guides

Evidence-based guides on TDEE, calorie deficits, macronutrients, BMI, body fat percentage, protein, and weight loss — written and clinically reviewed by Rex, RN, a registered nurse with 8+ years of clinical experience. Each article is grounded in peer-reviewed research with references cited, and pairs with a free calculator so you can apply the evidence directly to your own data.

Calories & Weight Loss

What Is TDEE? How It's Calculated

The four components of daily energy expenditure and why a single calorie number is never the full picture.

TDEE for Women: Why the Numbers Are Always Different

How the menstrual cycle shifts calorie needs by up to 300 kcal/day — and what calculators miss.

Which BMR Formula Is Most Accurate?

Mifflin-St Jeor vs Harris-Benedict vs Katch-McArdle — when each applies and by how much they differ.

How Many Calories Should I Eat to Lose Weight?

Step-by-step: finding your TDEE, choosing a safe deficit, and why the math always overestimates progress.

Why Your Calorie Deficit Isn't Working

Five evidence-based reasons weight loss stalls — TDEE error, logging mistakes, metabolic adaptation, and more.

How Long Will It Take to Lose Weight?

Why real timelines are 20–40% longer than simple math predicts — and how to set realistic expectations.

Why Does My Weight Change Every Day?

Six physiological causes of daily scale variation — glycogen, sodium, GI content, hydration, hormones, and exercise — with specific numbers.

How to Lose Fat Without Losing Muscle

Five evidence-based strategies: protein targets, resistance training, deficit size, sleep quality, and strategic diet breaks — with specific numbers from the research.

Why Weight Loss Slows: How to Break a Plateau

Adaptive thermogenesis, NEAT compensation, and hormonal shifts cause every diet to stall. Five evidence-based strategies — including the MATADOR intermittent restriction trial — to break through.

Sleep and Weight Loss: How Poor Sleep Sabotages Your Results

Sleep restriction raises ghrelin, lowers leptin, suppresses NEAT, and directly increases caloric intake. Evidence from five controlled trials — and how much sleep is enough.

How Much Exercise Do You Need to Lose Weight?

The ACSM recommends over 250 minutes per week for significant weight loss — but exercise consistently produces only 30–65% of the fat loss the math predicts. Here's why.

Does Stress Cause Weight Gain? The Science of Cortisol

Chronic stress raises cortisol, which promotes visceral fat storage and drives appetite toward calorie-dense food. What the research actually shows — and what to do about it.

How Many Calories Should I Eat? A Registered Nurse Explains

How to calculate your calorie target from TDEE, why the 3,500 kcal rule overestimates weight loss, and the minimum safe thresholds you need to know.

Cardio vs Weights for Weight Loss: What the Research Shows

Aerobic exercise produces greater fat loss; resistance training preserves lean mass. The STRRIDE trial and five key comparisons — what the evidence says about combining both.

How Fast Can You Safely Lose Weight? What the Evidence Says

Clinical guidelines recommend 0.5–1 kg per week. Faster rates reliably increase lean muscle loss. What the research shows about choosing a rate — and protecting body composition.

Alcohol and Weight Loss: How Drinking Affects Your Calorie Balance

Alcohol is energy-dense, pauses fat oxidation, and increases appetite and food intake. What the evidence shows about drinking while working toward a calorie deficit.

Walking for Weight Loss: How Much You Need and What the Evidence Says

A systematic review of 26 trials found pedometer users increased daily steps by 2,491 and lost meaningful weight — but the physiology has an important catch worth understanding.

Body Composition

What Is a Healthy BMI?

WHO ranges, healthy weight by height, Asian-adjusted thresholds, and key limitations of BMI.

BMI vs Body Fat Percentage: Which Is More Accurate?

Four cases where BMI gets it wrong — and when body fat % gives a more meaningful picture.

How to Calculate Body Fat Percentage

Navy method, calipers, BIA, and DEXA — accuracy comparison and how to measure at home.

What Is a Healthy Body Fat Percentage?

ACE categories for men and women, age-adjusted ranges, essential fat minimums, and the skinny-fat paradox.

What Is My Ideal Weight?

Four clinical formulas for ideal weight — and why none of them should be treated as a fixed target.

How to Lose Belly Fat: What the Evidence Says

Visceral vs subcutaneous fat, why crunches don't work, and the six evidence-based factors that actually reduce abdominal fat.

Visceral Fat: What It Is, Why It's Dangerous, and How to Reduce It

Visceral fat surrounds your organs and raises metabolic risk even at a normal BMI. Waist circumference thresholds, the Framingham Study findings, and what actually reduces it.

Nutrition & Fitness

What Are Macros?

Protein, carbohydrates, and fat — what each does, how to calculate your targets, and five diet approaches compared.

How to Build Muscle: Calorie Surplus Guide

How much surplus you actually need, realistic muscle gain rates, and the muscle-to-fat ratio by bulk strategy.

How Much Protein Do I Need Per Day?

The RDA of 0.8 g/kg is a minimum — not a target. Evidence-based protein ranges for weight loss, muscle gain, athletic performance, and healthy ageing.

How Much Water Should I Drink?

Evidence-based daily intake targets by body weight, activity level, and climate — beyond the "8 glasses" rule.

What Is NEAT? The Hidden Variable in Your Calorie Burn

NEAT can vary by 2,000 kcal/day between individuals and is a primary reason weight loss always slows — what it is, why it drops during dieting, and how to increase it.

How to Increase Metabolism: What Actually Works

Muscle mass, protein thermogenesis, NEAT, sleep, and resistance training — the evidence-based strategies that genuinely raise metabolic rate, and why green tea and six-meal plans don't.

Body Recomposition: Can You Lose Fat and Build Muscle at the Same Time?

Body recomposition is real but its achievability depends on training history, body fat, and protein intake — the science, the key evidence, and when sequential phases work better.

Intermittent Fasting for Weight Loss: What the Evidence Says

IF works primarily by reducing total caloric intake — not through unique metabolic advantages. Evidence from the TREAT trial, ADF vs. CER comparisons, and early TRE research on metabolic benefits beyond weight loss.

Low Carb vs Low Fat Diet: What the Evidence Actually Says

Controlled trials show similar long-term weight loss — but the diets differ meaningfully on metabolic markers, speed of initial loss, and outcomes for people with type 2 diabetes.

Do Cheat Days Actually Work? What the Evidence Says

Cheat days promise a metabolic boost from rising leptin — but the science doesn't support the claim. What actually matters is the psychology of flexible versus rigid dietary control.

Protein and Weight Loss: How Much You Need and Why It Works

Protein reduces hunger, burns more calories in digestion, and preserves lean muscle during a deficit. The Weigle 2005 trial showed a spontaneous 441 kcal/day reduction from raising protein alone.

Mediterranean Diet and Weight Loss: What the Evidence Shows

In the 2-year DIRECT trial, the Mediterranean diet outperformed a low-fat diet for weight loss (−4.4 kg vs −2.9 kg) — not through metabolic magic but through better long-term adherence.

How to Count Macros: A Step-by-Step Guide to Macro Tracking

Four steps to set your protein, fat, and carbohydrate targets — with a worked example, common tracking errors, and how to log food accurately without guessing.

High Protein Foods: A Complete List With Grams Per Serving

Verified protein per serving (not just per 100g) across meat, fish, dairy, eggs, and plant sources — with a protein efficiency column showing grams per 100 kcal.