Health Jun 23, 2026

Why Protein and Carbs Are 4 Calories Per Gram and Fat Is 9 — The Atwater Factors Behind Every Macro Calculator

The 4-4-9 calorie-per-gram values for protein, carbs, and fat are Atwater factors — approximations from 19th-century bomb calorimetry experiments, corrected for digestibility and metabolic losses. Here's why fat has more than twice the calories per gram of carbs (carbon-hydrogen ratio), why fiber produces different calorie values than other carbohydrates, and why tracking macros to the gram implies more precision than the underlying measurement system actually supports.

Health Jun 20, 2026

Why Protein + Carbs + Fat, Converted Back to Calories, Doesn't Exactly Match Your Calorie Target

A macro calculator says 150g protein, 200g carbs, 70g fat — multiply each by its calories-per-gram, sum them, and the total often doesn't exactly match the calorie target they're based on. Here's why this is expected rounding (whole-gram display rounding, plus the simplified "4-4-9" calorie-per-gram figures themselves), why it compounds across three macros in either direction, and why it's not something that needs "correcting."

Health Jun 13, 2026

Ketogenic Diets and Nutritional Ketosis: What the Research Shows About Weight Loss, Performance, and Who Should Be Cautious

Ketogenic diets shift the body's fuel source from glucose to fat and ketones — a measurable metabolic state with the strongest evidence base in drug-resistant epilepsy. Here's how nutritional ketosis differs from dangerous diabetic ketoacidosis, what weight loss research actually shows over longer timeframes, and the mixed evidence on athletic performance.

Health Jun 10, 2026

Carbohydrates and Sports Performance: Glycogen, Carbo-Loading, and the Marathon Wall

Glycogen powers high-intensity exercise and runs out after 90–120 minutes — which is exactly why marathoners hit the wall. Here's the science of carbo-loading, carbohydrate intake during endurance events, the post-exercise glycogen window, and where low-carb approaches fit in sports nutrition.

Health Jun 9, 2026

How Much Protein Do You Actually Need? The Evidence-Based Answer

Protein is the macro where most people fall short of the evidence-backed optimal amount. Here's how much you actually need, why leucine triggers muscle protein synthesis, and which foods deliver protein most efficiently per calorie.

Health Jun 6, 2026

Macro Calculator — Find Your Daily Protein, Carbs & Fat Targets

Learn what macronutrients are, how macro ratios differ by goal (fat loss, muscle gain, endurance), how to calculate your daily protein, carbs, and fat targets, and why macros matter beyond calories.