What Is TDEE and Why Should Your Teen Know About It?
Total Daily Energy Expenditure is the single most important number for sustainable weight management.
TDEE stands for Total Daily Energy Expenditure — the number of calories your body burns in a day across all activities, from breathing to exercise.
Understanding TDEE removes the guesswork from weight management. Eating below your TDEE creates a calorie deficit, which leads to gradual weight loss. Eating above it leads to gain.
Why most diets fail
Most restrictive diets fail because they push intake too far below TDEE, causing energy crashes, hunger, and eventual rebound. A 300–400 kcal daily deficit below TDEE typically produces around 0.3–0.4 kg of weight loss per week — slow enough to be sustainable, fast enough to be motivating.
How TDEE is calculated
TDEE is calculated using the Mifflin-St Jeor equation for Basal Metabolic Rate (BMR) — the calories burned at complete rest — multiplied by an activity factor. For a moderately active 16-year-old girl, this typically falls between 1,800 and 2,300 kcal/day.
Why this matters for teenagers
Teenagers need more calories than most adults realise — not fewer. The growing body requires energy for bone development, hormonal function, and cognitive performance. Many teenage girls significantly undereat relative to their TDEE, which contributes to fatigue, poor concentration, and disrupted menstrual cycles. Understanding their TDEE helps teenagers make informed decisions rather than following arbitrary restriction.
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