How Much Body Fat Can You Lose in a Week?
When people start a new diet or fitness plan, one of the first questions I hear as a personal trainer in Bristol is:
👉 “How quickly can I lose weight?”
The honest answer: it depends what you mean by weight.
Fat Loss vs. Weight Loss
The number on the scale isn’t just body fat. It’s also:
Glycogen (your body’s stored carbs)
Water weight (which shifts up and down daily)
Food volume (literally what’s sitting in your stomach)
That’s why the scale can drop 2–3 kg in a week, even though you haven’t actually burned that much fat.
Here’s my favourite analogy:
👉 Imagine your body like your pockets. You’ve got your wallet, phone, keys, and coins. Some days, your pockets feel heavier because of all that stuff. That’s water and glycogen. When you cut carbs or salt, it’s like emptying your pockets — the weight drops quickly, but it’s not fat.
How Much Fat Can You Really Lose?
For most people:
0.5–1% of bodyweight per week is a safe, realistic rate of fat loss.
For someone at 80 kg, that’s about 0.5–1 kg of fat per week.
Faster than that usually means you’re mostly losing water and glycogen — not body fat.
This infographic shows a “realistic” comparison of daily possible body fat changes, vs things like glycogen, water and food in the GI tract. Please note these numbers are theoretical top end changes for all aspects.
Why Patience Pays Off
The goal isn’t just fast results. It’s building habits you can actually stick to. Crash diets might “empty your pockets” quickly, but they don’t set you up for long-term success.
At Small Group Personal Training Bristol, we help people lose fat in a way that’s:
âś… Realistic
âś… Sustainable
âś… Flexible to your lifestyle
Final Takeaway
You can lose weight quickly — but true fat loss happens at a steady pace. Focus on consistency, not quick fixes, and you’ll actually keep the results.
đź’ˇ Want support with your own fat loss journey? Our personal training in Bristol helps busy people get results without fad diets or endless cardio.