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How Many Calories Should I Eat to Lose Weight? (Calculate Yours)

TDEE, Calorie Deficit, and Why the 1200-Calorie Diet Is Hurting You

Coach Nirbhay30 March 20267 min read

If you want to lose weight, you've probably Googled "how many calories to lose weight" and been met with generic advice like "eat 1,200 calories a day." Let me be clear as a fitness coach: unless you are a small child, an active adult eating 1,200 calories a day is setting themselves up for metabolic disaster.

Weight loss is math, but it is highly individualised math. In this guide, I will show you exactly how to calculate your personal calorie target to lose weight sustainably, without starving yourself.

Step 1: Understand Your TDEE

Before you can cut calories, you must know how many calories your body burns on a daily basis. This is your Total Daily Energy Expenditure (TDEE). Your TDEE is made up of four things:

  • BMR (Basal Metabolic Rate): Calories burned just staying alive (breathing, organ function). Makes up ~70% of your TDEE.
  • NEAT (Non-Exercise Activity Thermogenesis): Calories burned walking, talking, fidgeting. Makes up ~15%.
  • TEF (Thermic Effect of Food): Calories burned digesting your meals. Protein burns the most. Makes up ~10%.
  • EAT (Exercise Activity Thermogenesis): Calories burned during your actual gym workout. Makes up only ~5%!

To find your BMR, scientists use the Mifflin-St Jeor equation. Don't worry about doing the complex math yourself; you can use any free TDEE calculator online. You input your gender, age, weight, height, and activity level, and it outputs your maintenance calories (your TDEE).

Step 2: Set the Calorie Deficit (The Sweet Spot)

Once you know your TDEE (maintenance calories), you subtract calories to enter a calorie deficit for weight loss. But how much should you subtract?

The sweet spot for sustainable fat loss without losing muscle is a 300 to 500 calorie deficit per day.

Let's look at an example. If your TDEE calculator says you burn 2,500 kcal a day:

  • Maintenance: 2,500 kcal (weight stays the same)
  • Fat Loss Target: 2,000 to 2,200 kcal per day
  • Expected Result: 0.3kg to 0.5kg of pure fat loss per week.

The 1,200-Calorie Myth: Why Crash Diets Fail

Why not just eat 1,200 calories and lose weight faster? Because of a phenomenon called "Metabolic Adaptation."

When you drastically under-eat, your body panics. It interprets this extreme deficit as starvation. To protect your vital organs, it drastically lowers your NEAT (you become inherently lazier and stop fidgeting), crashes your hormones (testosterone and thyroid levels plummet), and begins breaking down muscle tissue for energy.

You lose weight rapidly for two weeks. Then, your metabolism down-regulates to match the 1,200 calories. Your weight loss completely stalls. And worst of all, when you inevitably binge-eat because you are starving, your down-regulated metabolism stores all that excess food rapidly as fat. This is the classic "yo-yo diet" trap.

Sample Calorie Targets by Bodyweight

While you should calculate your exact TDEE, here is a general reference table for active individuals (training 3-4 days a week) looking to lose fat safely:

Current WeightGenderEstimated TDEESafe Deficit Target
60 kgFemale~1,900 kcal~1,500 kcal
70 kgMale~2,300 kcal~1,800 - 1,900 kcal
80 kgMale~2,600 kcal~2,100 - 2,200 kcal
90 kgMale~2,800 kcal~2,300 - 2,400 kcal
One-Time Session

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Video Call Consultation with Coach Nirbhay

Most people's problem isn't effort — it's starting from the wrong calorie number. In a 1-on-1 video call, I calculate your exact TDEE, set your deficit, and build out a realistic eating approach around your lifestyle and Indian food preferences. It's a one-time investment that saves months of trial and error. You'll leave the call knowing exactly what to do.

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Recalibrating as You Lose Weight

Here is what most people forget: as you lose weight, your body requires fewer calories to exist. A 90kg body requires more energy to move than an 80kg body. Therefore, the diet that got you from 90kg to 80kg will NOT get you from 80kg to 70kg.

You must periodically recalculate your TDEE every time you lose 2-3kg to ensure you remain in a deficit.

Stop Guessing with Your Diet

Calculating calories is just step one. What those calories are made of (your macronutrients — protein, carbs, and fats) dictates whether you lose muscle or fat, and determining what foods to eat to hit those numbers without going hungry is the real challenge.

Frequently Asked Questions

Is it true that I have to eat 1,200 calories to lose weight if I am a short woman?
Rarely. Even a short, sedentary woman has a BMR around 1,200-1,300. Adding in any daily activity pushes TDEE higher. Eating at least 1,400-1,500 kcal while increasing physical activity (like getting 10k steps) is a vastly superior strategy to starvation.
Do I need to count calories forever?
No. Tracking calories aggressively for 3-6 months acts as an educational tool. You learn portion sizes and the caloric density of foods. Over time, you can transition to mindful eating with a solid baseline knowledge.
Why did my weight loss stop even though I am eating in a deficit?
Your metabolism has down-regulated, you are unconsciously moving less (decreased NEAT), or you are under-reporting your calories (not tracking oils, sauces). You likely need a diet break (eating at maintenance for 2 weeks) or a slight calorie adjustment downwards.
What happens if I eat under my BMR?
Eating beneath your Basal Metabolic Rate forces your body to severely compromise on hormonal production, immune function, and muscle retention. It is generally advised against by all nutrition professionals.
Can I eat junk food as long as it fits my calorie deficit?
Yes, for weight loss (thermodynamics). No, for health, satiation, and body composition. If you spend your deficit entirely on sugar, you will be constantly starving, lacking protein for muscle retention, and feeling exhausted.