How Fast Should You Lose Weight? A Sustainable Rate, Explained
For most adults, a sustainable rate of weight loss is about 0.5 to 1kg (1 to 2lb) a week, which is the range the NHS recommends. Lighter people, and anyone already fairly lean, will usually do better at the lower end; people with more to lose can often sit nearer the top, especially early on. Faster is possible, but it tends to cost more muscle, more hunger and more of your training, and it is harder to keep off. The useful question is not the fastest rate you can bear, but the fastest rate you could keep up for three or four months without your life falling apart.
Why a “safe” rate is really about what lasts
There is nothing magic about one kilo. The range exists because of the trade-offs either side of it.
- Too slow and progress is so hard to see in the noise of daily weight changes that motivation fades. If the scales barely move in a month, most people give up or assume the plan is not working.
- Too fast and the deficit needed is large. Hunger climbs, sleep can suffer, training performance drops and a bigger share of what you lose tends to come from muscle rather than fat. Losing weight very quickly is also a recognised risk factor for gallstones, one reason the NHS says very low calorie diets are not suitable for everyone.
The middle ground lets you keep training hard, eat in a way that resembles normal life, and still see the trend move every couple of weeks. That is what makes it sustainable, and sustainability is what decides whether the weight stays off.
Scale it to your own body
A fixed kilo a week means very different things to a 60kg person and a 120kg person. Many coaches, myself included, think in percentages of body weight instead. As a working guide:
| Your situation | Sensible weekly target | Example at 80kg |
|---|---|---|
| Quite a lot to lose, new to training | Around 0.75 to 1% of body weight | 0.6 to 0.8kg |
| A moderate amount to lose, training regularly | Around 0.5 to 0.75% | 0.4 to 0.6kg |
| Already fairly lean, wants to keep strength | Around 0.25 to 0.5% | 0.2 to 0.4kg |
These are coaching rules of thumb rather than medical thresholds, and they sit within the NHS range for most people. The leaner you are, the more muscle you stand to lose by rushing, so the slower you should go.
What that means in calories, roughly
To lose weight you need to take in less energy than you use, consistently. A commonly used rough figure is that a daily deficit of around 500 to 600 calories produces something like half a kilo a week. Treat that as a starting point, not a law: the body adapts, water shifts, and calculators are estimates. If the language of deficits feels unfamiliar, read what a calorie deficit is, explained without the jargon and then work out your maintenance calories as a baseline. Here the focus is on rate: how fast to aim for and how to know whether you are on it.
Why the first fortnight lies
Nearly everyone loses more in the first week or two than they will later, often a couple of kilos. Most of it is water and the weight of food in the gut. Cutting back on carbohydrate and salt, eating less overall and drinking more water all shift fluid quickly. It is real weight but not mostly fat, and it does not continue.
The mistake is to judge the plan on week one, then panic in week three when the rate drops to half a kilo. That is the plan working. Set your expectations from week three onwards. Our article on why the scales go up after a good week explains the day-to-day swings in more detail.
How to read the scales honestly
Daily weight can easily swing by a kilo or more because of salt, a late dinner, a hard session, poor sleep, hormonal cycles or travel. A single weigh-in tells you almost nothing about fat loss. A weekly average tells you a lot.
- Weigh yourself first thing in the morning, after the loo, before food or drink, most days of the week.
- Write it down. Ignore any individual number.
- At the end of each week, take the average.
- Compare this week’s average with last week’s. That difference is your rate.
- Judge the plan on two to three weeks of averages, not one.
Add a waist measurement every fortnight, at the navel, relaxed, same time of day. If the waist is coming down while the scales stall, you are often losing fat and holding water, or gaining a little muscle if you are new to lifting. In the studio we also use the InBody scanner to track body composition over time, which is useful for the same reason: it separates trends in muscle and fat that the scales lump together. Like any method it has limits, which is worth understanding before you rely on any single number.
When to adjust the rate
A sustainable plan is not fixed. Check every two to three weeks and adjust using the averages.
- Losing faster than your target for more than three weeks (after the first fortnight): add back a little food, usually 100 to 200 calories a day, mostly from carbohydrate around training. Especially if training is suffering or you are constantly hungry.
- On target: change nothing. This is the hardest instruction to follow.
- Slower than target for three weeks with no change in waist measurement either: first check honestly whether the plan is being followed at weekends, then reduce intake slightly or increase daily walking. If you have been dieting for a long time, a planned pause may help more, a short, deliberate diet break at maintenance.
Change one variable at a time, and by a small amount, or you will not know what worked.
Signs you are going too fast
- Strength dropping noticeably across several sessions, not just one bad day.
- Persistent hunger that crowds out concentration at work.
- Sleep getting worse, or waking in the night hungry.
- Feeling cold, flat or irritable most of the time.
- Planning your days around not eating.
Any two of those together are a good reason to slow down, even if the rate is technically within the recommended range. Strength training two or more days a week and enough protein are the two biggest protections for your muscle while you diet. Spreading protein across three or four meals is the simplest way to get enough.
A realistic timeline
Divide what you want to lose by a sensible weekly rate, then add 25 to 50 percent for real life: holidays, illness, a busy month at work, Christmas. Someone hoping to lose 10kg at half a kilo a week has a 20-week plan on paper, which in practice is closer to six months. That is not slow. It is what keeping it off looks like, and a body that has been brought down gradually, while training, tends to look and feel quite different from one that has been crash-dieted to the same number.
Check with your GP first if…
Speak to your GP before starting a weight loss plan if you have diabetes or take medication that affects blood sugar, have a heart condition or high blood pressure, are pregnant or breastfeeding, have a history of disordered eating, or are considering a very low calorie diet. The same goes if you are losing weight without trying, which always deserves a medical conversation.
Where coaching helps
The hard part of a sensible rate is not the arithmetic. It is holding your nerve through the noisy weeks and adjusting calmly instead of overreacting. In private 1-1 training with Artem in Highgate we track the weekly averages, waist and InBody readings alongside your training, so the rate is set for your body and adjusted with evidence rather than mood. You can read how sessions run on the personal training page, and more about the building on the Highgate House homepage.
Questions we get asked
Is losing 2kg a week safe?
For a week or two at the start, much of that is water. As an ongoing rate it is faster than the NHS recommends for most people and is best done only under medical supervision.
Why did I lose weight quickly at first and then slow down?
Early losses are largely water and gut contents. From around week three, the slower rate reflects fat loss more accurately.
Should I weigh myself every day?
If you can treat it as data and use the weekly average, yes. If a single number ruins your morning, weigh in two or three times a week and track your waist as well.
Does losing weight slowly mean it stays off?
Rate alone does not guarantee it, but a gradual approach builds the habits that do. What happens after the diet matters as much, which is covered in maintaining weight loss.
Book with The Highgate House
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