The “eat 1200 calories to lose weight” advice is wrong for most adults — it’s too low for many people, ignores your individual metabolism, and almost always leads to muscle loss and eventual rebound. Here’s how to calculate the right calorie target for your body and goal.
Step 1 — Calculate Your Basal Metabolic Rate (BMR)
BMR is how many calories you burn just by existing — breathing, digestion, keeping organs functioning. Use our calorie calculator which uses the Mifflin-St Jeor equation (the most accurate for most people):
- Men: BMR = 88.36 + (13.4 × weight kg) + (4.8 × height cm) − (5.7 × age)
- Women: BMR = 447.6 + (9.2 × weight kg) + (3.1 × height cm) − (4.3 × age)
Step 2 — Calculate Your Total Daily Energy Expenditure (TDEE)
Multiply your BMR by your activity multiplier:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Desk job, little exercise | BMR × 1.2 |
| Lightly active | Exercise 1-3 days/week | BMR × 1.375 |
| Moderately active | Exercise 4-5 days/week | BMR × 1.55 |
| Very active | Hard exercise 6-7 days/week | BMR × 1.725 |
Your TDEE is your maintenance calories — the amount you’d eat to stay exactly the same weight.
Step 3 — Apply a Sustainable Deficit
Use our calorie deficit calculator to find your target based on your goal weight and date.
| Deficit | Weekly Loss | Best For |
|---|---|---|
| 250 kcal/day | ~0.25 kg/week | Athletes preserving muscle, small goals |
| 500 kcal/day | ~0.5 kg/week | Most people — sustainable, effective |
| 750 kcal/day | ~0.75 kg/week | Larger goals, maintain minimum 1400 kcal |
Why 1200 Calories Is Usually Too Low
For a moderately active 35-year-old woman at 70kg, TDEE is approximately 2,000 calories. A 1,200 calorie target creates an 800-calorie daily deficit — leading to:
- Significant muscle loss (the body breaks down muscle for energy when deficit is too large)
- Hormonal disruption (cortisol rises, thyroid function decreases)
- Extreme hunger that typically leads to binge eating
- “Metabolic adaptation” — metabolism slows, making future weight loss harder
Protein: The Most Important Macro for Weight Loss
Protein preserves muscle during a calorie deficit, keeps you fuller longer, and burns more calories to digest than carbs or fat (the “thermic effect”). Target 1.6-2.2g of protein per kg of bodyweight while losing fat. Our protein intake calculator gives you exact targets.
ADHD Planner + Calorie Tracking Section
Our ADHD planner includes a simple daily food and wellness tracker — designed for people who hate complicated nutrition apps.
Get the Planner →No — but awareness helps. Research shows that people consistently underestimate food intake by 30-50%. Tracking for 4-8 weeks to understand your actual eating patterns is valuable, even if you don’t track forever. Apps like Cronometer and MyFitnessPal make this easy.
Every 10-15 lbs of weight lost (or 5-7 kg), or if weight loss stalls for 3+ consecutive weeks. As you lose weight, your TDEE decreases, so your deficit shrinks unless you adjust. Recalculating prevents plateau.