What is a calorie deficit? A simple guide to losing weight

How it works

Your body burns energy all day — to keep you alive, to digest food and to move. When you eat less than that total, your body makes up the difference from stored energy, including fat.

How big should the deficit be?

Slow and steady tends to be easier to stick with. The NHS suggests that cutting around 600 calories a day can help most people lose about 0.5kg (1lb) a week. Very large deficits can leave you tired and hungry, and are harder to keep up.

Ways to create a deficit

You can eat a little less, move a little more, or both.

• Swap sugary drinks for water or zero-calorie drinks.
• Build meals around protein and vegetables, which help you feel full.
• Watch portion sizes of oils, sauces and snacks — they add up quickly.
• Add more daily movement, such as walking.

Common mistakes

• Guessing portions instead of logging them.
• Forgetting drinks, cooking oil and small bites.
• Cutting calories too hard, then overeating at the weekend.
• Expecting the scale to drop every single day — weight naturally goes up and down.

Track it with Loggah

Loggah shows your calories and macros against your daily target, so you can see your deficit at a glance instead of guessing.

If you have a medical condition or are unsure what's right for you, speak to your GP before changing your diet.