🎥
Video Coming Soon
This lesson's video is currently being produced.
Description
Key Concepts
My Notes
Discussion

Lesson Overview

Every body composition change is governed by energy balance. Understanding how energy is consumed, stored, and expended is the foundation for any meaningful nutritional conversation with clients.

Learning Objectives

  • Define Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE)
  • Apply the Mifflin-St Jeor equation to estimate BMR
  • Explain activity multipliers for TDEE calculation
  • Describe how caloric surplus and deficit drive body composition change
  • Explain metabolic adaptation and its implications for clients

What is BMR?

Basal Metabolic Rate is the minimum energy the body needs to sustain vital functions — breathing, circulation, cell repair, temperature regulation — at complete rest. BMR accounts for roughly 60–75% of total daily energy expenditure in sedentary individuals.

The most accurate widely-used formula is the Mifflin-St Jeor equation:

Male
(10 × kg) + (6.25 × cm) − (5 × age) + 5
Female
(10 × kg) + (6.25 × cm) − (5 × age) − 161

From BMR to TDEE

TDEE = BMR × activity factor. Typical multipliers: sedentary (×1.2), lightly active (×1.375), moderately active (×1.55), very active (×1.725). Most AURUM clients are between 1.375 and 1.55.

A sustained daily deficit of ~500 kcal leads to approximately 0.5 kg of fat loss per week. Overly aggressive deficits risk muscle loss, hormonal disruption, and reduced training performance — moderate, consistent deficits are always preferred.