What Is a Calorie Deficit? Simple Explanation
If you want to lose weight, you've probably heard you need to be in a "calorie deficit." But what does that actually mean? Here's a simple, no-nonsense explanation.
The Simple Definition
A calorie deficit is when you consume fewer calories than your body burns. That's it.
Calories In < Calories Out = Calorie Deficit
When you're in a deficit, your body needs to get energy from somewhere, so it taps into stored energy — primarily body fat. This is how you lose weight.
How It Works
Your body burns calories constantly — even while sleeping. This total daily burn is called your TDEE (Total Daily Energy Expenditure).
Example:
- • Your TDEE: 2,000 calories/day
- • You eat: 1,500 calories/day
- • Your deficit: 500 calories/day
That 500-calorie daily deficit adds up to about 1 pound of fat loss per week (since 1 lb of fat ≈ 3,500 calories).
Note: Weight loss isn't always linear due to water retention, but over time, a consistent deficit = consistent fat loss.
How to Calculate Your Deficit
- 1
Find Your TDEE
Use a TDEE calculator to estimate how many calories you burn daily.
- 2
Subtract 300-500 Calories
This creates a moderate deficit for steady, sustainable weight loss.
- 3
Track and Adjust
If you're not losing weight after 2-3 weeks, reduce by another 100-200 calories.
Calculate Your Deficit
How Big Should Your Deficit Be?
Bigger isn't always better. Here's a guide:
Small Deficit (200-300 cal) ✓
Slow but very sustainable. Good for people close to goal weight or who want to preserve muscle.
Moderate Deficit (400-500 cal) ✓ Recommended
The sweet spot for most people. ~1 lb/week loss without extreme hunger.
Large Deficit (700-1000 cal) ⚠️
Faster results but harder to sustain. Higher muscle loss risk. Only for very overweight individuals.
Extreme Deficit (1000+ cal) ✗
Not recommended. Leads to muscle loss, metabolic adaptation, and is nearly impossible to maintain.
How to Create a Deficit
You can create a deficit through:
Eating Less
Reduce food intake
Moving More
Increase activity
Both
Most effective
Most experts recommend a combination: eat slightly less AND move a bit more. This way, you don't have to cut food drastically or exercise for hours.
Common Questions
Will I lose muscle in a deficit?
Some muscle loss is normal, but you can minimize it by eating enough protein (0.7-1g per lb body weight) and doing resistance training.
Will my metabolism slow down?
Slightly, yes — this is called metabolic adaptation. Moderate deficits cause less adaptation than extreme ones.
How do I know if I'm in a deficit?
If you're losing weight over 2-4 weeks, you're in a deficit. The scale is your feedback tool.
Track Your Deficit Easily
Pandish helps you stay in a calorie deficit with AI food scanning and daily tracking.