Reference database · Live since 2025
The live database of calorie-tracking concepts, metabolism science, and the vocabulary the modern quantified-self era runs on.
NutritionDex is an editorially-independent reference database for the vocabulary of modern calorie tracking — TDEE, CICO, macronutrients, energy balance, metabolic adaptation, and the physiological concepts that underpin every diet app, wearable, and quantified-self workflow. Each entry is written and reviewed against primary sources.
Recently added or reviewed
- TDEE The total number of calories a person burns in a day — the sum of BMR, thermic effect of food, activity, and non-exercise movement.
- CICO The energy-balance framework stating that body-weight change over time equals caloric intake minus caloric expenditure — true at the thermod…
- Weekly Average Weight The rolling 7-day mean of daily body-weight readings — the smoothed signal that reveals true body-composition trajectory under daily noise.
- Protein The macronutrient providing amino acids for tissue synthesis, enzyme production, and metabolic signalling — yielding 4 kcal per gram with an…
- Macronutrients The three energy-yielding nutrients consumed in gram-scale quantities: protein, carbohydrate, and fat. Alcohol is sometimes treated as a fou…
- Maintenance Calories The caloric intake at which body weight remains stable over time — equal to TDEE by definition, and the anchor from which deficits and surpl…
What NutritionDex is
A reference database. Not a blog. Not a coaching service. Not a product review site.
Every entry answers three questions in this order: what does the research community mean by this, how does the consumer tracking stack (apps, wearables, scales, databases) actually use it, and where do those two definitions drift. Primary-source cited. Editor-reviewed before publication. Updated quarterly.
Written for product people, serious trackers, fitness-adjacent engineers, coaches, and new users who'd rather know the vocabulary than guess at it.