How Many Calories Should I Eat to Lose Fat?

naomijohnsonfitnes
May 15
2 min read

If you’re trying to lose fat, you’ve probably heard the phrase: “It all comes down to calories in vs. calories out.” And while that’s broadly true, figuring out how many calories you personally should eat to lose fat isn’t always so simple. In this post, I’ll break down how fat loss works, how to calculate your calorie needs, and how to adjust over time.

Fat Loss 101: The Calorie Deficit

To lose fat, your body needs to be in a calorie deficit—that means you're consuming fewer calories than you burn. When that happens consistently, your body turns to stored fat for energy. But the key word here is: consistently. Too large a deficit? You might feel tired, hungry, and risk losing muscle. Too small a deficit? You might not see results—or see them very slowly.

Step 1: Calculate Your Maintenance Calories (TDEE)

Your Total Daily Energy Expenditure (TDEE) is the number of calories your body burns in a day, including everything from breathing to workouts. You can estimate it using this simple formula (based on the Mifflin-St Jeor equation):

Step A: Calculate your Basal Metabolic Rate (BMR)

For women: BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (years) – 161

For men: BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (years) + 5

Step B: Multiply by your activity level

Activity Level	Multiplier
Sedentary	1.2
Light exercise (1-3x/week)	1.375
Moderate (3-5x/week)	1.55
Heavy (6-7x/week)	1.725
Athlete (twice daily)	1.9

Example: A 30-year-old woman, 70 kg, 165 cm tall, moderately active (3–5x/week):

BMR = 10×70 + 6.25×165 – 5×30 – 161 = 1466.25
TDEE = 1466 × 1.55 = ~2272 calories/day

Step 2: Create a Calorie Deficit

To lose fat safely and effectively, reduce your calorie intake by 15–25% of your TDEE.

Mild deficit (slow & steady): 15%
Moderate deficit (most common): 20%
Aggressive (short term only): 25%

Using the example above (TDEE = 2272):

20% deficit = 2272 × 0.80 = ~1818 calories/day

That’s your target daily intake for fat loss.

Step 3: Track Progress and Adjust

You might start losing fat on that calorie target, but your needs can change. Here's what to track:

Weight trends (over weeks, not days)
Waist measurements or progress photos
Energy, hunger, and performance in workouts

If fat loss stalls for 2–3 weeks:

You may need to lower calories slightly (5–10%)
Or improve accuracy in tracking food (hidden calories add up!)

Tips for Staying on Track

Use apps like MyFitnessPal, Cronometer, or MacrosFirst
Weigh food when possible—eyeballing can lead to underestimating calories
Don’t drop calories too low; it backfires in the long run
Be patient. Sustainable fat loss is usually 0.5–1 kg (1–2 lbs) per week

Final Thoughts

There’s no one-size-fits-all number of calories for fat loss—but with a little math and consistency, you can dial in what works for your body.

Remember: Fat loss isn’t about eating as little as possible. It’s about eating just enough to fuel your life, your workouts, and your goals—while letting your body burn the rest from stored fat.