How does Losertown calculate weight loss over time?

Losertown projects weight by calculating weekly deficit (TDEE − intake × 7 days) and converting to weight loss (deficit ÷ 7,700 cal/kg). Each week, it recalculates TDEE based on the new, lower body weight — capturing how TDEE decreases as you lose weight, which is why loss rate naturally slows over time.

Why does weight loss slow down as I lose more weight?

Smaller body = lower TDEE. If you maintain the same calorie intake, the deficit shrinks as you get lighter. For example: at 200 lbs, a 1,500 cal intake might create a 600 cal deficit. At 160 lbs (same intake), the deficit might be only 350 cal because your TDEE dropped by 250 calories. The deficit gets smaller automatically.

What is a realistic weekly weight loss rate?

0.5–1.0 kg per week (1–2 lbs) is a commonly recommended sustainable rate. This corresponds to a 500–1,000 calorie daily deficit. Faster rates are possible but increase risk of muscle loss and dietary fatigue. Very low calorie diets (>750 cal/day deficit) should be medically supervised.

How accurate are TDEE calculators for predicting weight loss?

TDEE calculators estimate average energy expenditure — individual variation is ±10–20%. Some people have higher or lower metabolisms than calculated. Track actual weight weekly and adjust calorie intake: if not losing at the expected rate after 2–3 weeks, reduce intake by 100–200 cal/day. Don't over-adjust short-term (weekly water weight fluctuations can obscure true trends).

How Losertown-Style Weight Projections Work: TDEE, Deficit, and Realistic Timelines

Understand how Losertown-style weight loss projections calculate your expected weight over time from daily calorie deficit, TDEE, and adaptive metabolism adjustments.

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What Is a Losertown-Style Projection?

Losertown (losertown.org) pioneered a web tool that simulates your expected weight change over time based on your TDEE (Total Daily Energy Expenditure) and planned calorie intake. The tool shows you a weight trajectory week-by-week, accounting for the fact that TDEE decreases as you lose weight.

The Core Model

Daily deficit = TDEE − Daily Calorie Intake

Weekly weight loss = Weekly deficit ÷ 7,700 (calories per kg of body mass) *(or ÷ 3,500 for pounds)*

Key complication: TDEE isn't constant — as you lose weight, you need fewer calories to maintain your smaller body. This is why weight loss isn't perfectly linear over long periods.

TDEE Calculation

TDEE = BMR × Activity Factor

Mifflin-St Jeor BMR (recommended): - Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 - Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Activity Multipliers: | Level | Multiplier | |-------|-----------| | Sedentary | 1.2 | | Lightly active | 1.375 | | Moderately active | 1.55 | | Very active | 1.725 | | Extremely active | 1.9 |

The Adaptive Metabolism Adjustment

As weight decreases, BMR decreases proportionally. Each week, the model recalculates TDEE based on current weight:

Updated BMR = Mifflin-St Jeor formula with current weight

This means a 500 calorie/day deficit at 200 lbs becomes a 450 calorie/day deficit by the time you reach 180 lbs (if calorie intake stays constant), because your TDEE dropped by 50 calories.

This explains why weight loss "slows down" over time — it's not metabolic adaptation in the hormonal sense (primarily), it's physics: smaller body = less calorie maintenance.

Practical Weekly Projection

Example: Female, 35 years old, 5'6", starting at 180 lbs, sedentary, eating 1,500 cal/day: 1. Current BMR: 10 × 81.6 + 6.25 × 167.6 − 5 × 35 − 161 = 816 + 1,047.5 − 175 − 161 = 1,527.5 2. TDEE = 1,527.5 × 1.2 = 1,833 cal/day 3. Daily deficit: 1,833 − 1,500 = 333 cal/day 4. Weekly deficit: 333 × 7 = 2,331 cal/week 5. Weekly loss: 2,331 ÷ 7,700 = 0.30 kg/week (0.67 lbs/week)

At this rate, reaching 165 lbs (7.5 kg loss) takes approximately 25 weeks.

Common Weight Loss Expectations

Calorie Deficit	Expected Loss Rate
250 cal/day	~0.23 kg/week (0.5 lb)
500 cal/day	~0.45 kg/week (1.0 lb)
750 cal/day	~0.68 kg/week (1.5 lb)
1,000 cal/day	~0.91 kg/week (2.0 lb)

Deficits over 1,000 cal/day significantly increase muscle loss and metabolic adaptation risks.

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Frequently Asked Questions

How does Losertown calculate weight loss over time?: Losertown projects weight by calculating weekly deficit (TDEE − intake × 7 days) and converting to weight loss (deficit ÷ 7,700 cal/kg). Each week, it recalculates TDEE based on the new, lower body weight — capturing how TDEE decreases as you lose weight, which is why loss rate naturally slows over time.
Why does weight loss slow down as I lose more weight?: Smaller body = lower TDEE. If you maintain the same calorie intake, the deficit shrinks as you get lighter. For example: at 200 lbs, a 1,500 cal intake might create a 600 cal deficit. At 160 lbs (same intake), the deficit might be only 350 cal because your TDEE dropped by 250 calories. The deficit gets smaller automatically.
What is a realistic weekly weight loss rate?: 0.5–1.0 kg per week (1–2 lbs) is a commonly recommended sustainable rate. This corresponds to a 500–1,000 calorie daily deficit. Faster rates are possible but increase risk of muscle loss and dietary fatigue. Very low calorie diets (>750 cal/day deficit) should be medically supervised.
How accurate are TDEE calculators for predicting weight loss?: TDEE calculators estimate average energy expenditure — individual variation is ±10–20%. Some people have higher or lower metabolisms than calculated. Track actual weight weekly and adjust calorie intake: if not losing at the expected rate after 2–3 weeks, reduce intake by 100–200 cal/day. Don't over-adjust short-term (weekly water weight fluctuations can obscure true trends).

Last updated 7/28/2026