Someone gets in touch wanting to lose fat quickly and their first idea is usually the same: cut calories as low as they can manage.
The first week usually looks great because the scale drops. A few weeks later, they’re hungry all the time, training feels awful and one quiet week on the scale convinces them they need to cut their food again.
That’s where a fairly simple fat-loss phase can turn into a slog.
Start With Your Maintenance Calories
Your maintenance calories are roughly the amount you would need to eat each day to keep your weight stable.
A calorie calculator will give you an estimate, but it won’t be exact. It doesn’t know exactly how much you move, how active your job is or what the rest of your week looks like. Use that number as a starting point and see what happens to your weight.
Around 15–20% below maintenance is a reasonable place to start.
If your maintenance is roughly 2,400 calories, that would put you somewhere between 1,920 and 2,040 calories per day. Call it 2,000 and move on.
Once you get closer to 25–30% below maintenance, the diet becomes much harder. That might be manageable for someone with a lot of fat to lose, but it’s not where I’d start without a good reason.
If you’re already fairly lean, train hard or have a physical job, stay closer to the lower end.
Around 0.5% of body weight per week is a decent rate to aim for. At 80kg, that would be roughly 400g per week. Someone with more fat to lose may be fine closer to 1%, particularly at the beginning.
The first week can be quicker because some of the drop comes from water and less food sitting in your system. Don’t use that first week to judge the whole plan.
What Happens When You Push It Too Far?
A 2011 study on elite athletes gave one group a target of losing 0.7% of their body weight per week and another a target of 1.4%. The faster group ended up losing closer to 1% per week.
The slower group gained lean mass and improved more on some strength measures. Lean mass stayed roughly the same in the faster group.
It was a small study on elite athletes, so I wouldn’t treat 0.7% like some magic number. It does show why trying to lose weight as quickly as possible isn’t always a great idea when you’re still training.
Your own workouts can tell you quite a bit as well. Everyone has an off day, but if you keep missing reps you were hitting comfortably a few weeks ago, pay attention.
You don’t need to set personal bests every week while losing fat. Your full programme shouldn’t suddenly fall apart either.
Protein helps you hold on to the muscle you’ve already built. I’ve covered how much to aim for in How Much Protein Do You Actually Need?
Hunger matters too. Being hungry before a meal is normal. Thinking about food all day and regularly losing control at the weekend suggests the setup isn’t working very well.
Poor sleep and stress can cause some of the same problems. Look at the full week before blaming the calories.
Use the Trend Instead of One Weigh-In
Your weight can move up or down for reasons that have nothing to do with body fat.
A later meal, more carbohydrates, extra salt or having more food in your system can all push the number up. That doesn’t mean you’ve suddenly gained body fat. I’ve covered why in more detail in Why Your Weight Can Jump Overnight.
Use several weigh-ins across the week and compare the averages. Give it two to three weeks before deciding whether the starting calories are working.
When to Change Your Calories
If your weekly average has been flat for two to three weeks, check that you’ve actually been close to the target before cutting anything.
Weekends, drinks, sauces, cooking oils and meals out are usually where the extra calories creep in. There’s no point lowering the target if the current one hasn’t been followed.
If you’ve been consistent and the average still isn’t moving, take another 100–200 calories off and see what happens over the next couple of weeks.
If you’re losing much faster than planned and your training or hunger has gone downhill, add 100–200 calories back in.
If your average weight is coming down and you’re still managing your training, keep going. There’s nothing to fix.
If you want help setting your calories and putting the rest of your diet together, download my free Fat Loss Blueprint. It shows you how to organise your meals and build a plan you can actually stick to.
