How much weight can you safely lose in a month?
About 2 to 4 kg (4 to 8 lb). That’s the NHS pace. 5 kg or 10 kg is faster. And week one can fool you: part of that drop is water.
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How much weight can you lose in a month?
About 2 to 4 kg in 4 weeks, or 4 to 8 lb. The NHS says to lose weight steadily and aim for 0.5 to 1 kg, or 1 to 2 lb, a week.
The NHS gives no monthly maximum. It gives a pace. Four weeks at that pace is your month.
- Below 2 kgSlower than the NHS pace.
- 2 up to 4 kgNHS pace: 0.5 to 1 kg a week.
- Above 4 up to 8 kgFaster than the NHS pace.
- Above 8 kgMore than twice the NHS pace.
Source: NHS
Slower still counts. The NHS says losing just 5 to 10% of your body weight can improve your health.
Pick a goal for the next 4 weeks between 2 and 4 kg. Write it down with today’s weight.
Can you lose 5 kg or 10 kg in a month?
Only by going faster than the NHS aim.
| Goal in 4 weeks | Each week | Against the NHS aim |
|---|---|---|
| 2 to 4 kg (4 to 8 lb) | 0.5 to 1 kg | Matches it. |
| 10 lb (about 4.5 kg) | 2.5 lb | Above the 1 to 2 lb aim. |
| 5 kg | 1.25 kg | Above the 1 kg top end. |
| 10 kg | 2.5 kg | More than twice the top end. |
Source: NHS
The NHS says do not lose weight suddenly with diets. Losing weight quickly, for example after weight loss surgery, may make gallstones more likely. These are small stones that form in the gallbladder.
Some people do need to lose weight fast. The NHS may offer a dietitian’s help with a very low calorie diet, under 800 or 1,200 calories a day. These are not suitable or safe for everyone.
They’re usually only for people whose weight affects other health conditions. NICE says to consider under 800 a day only inside a specialist weight service, for no more than 12 weeks. It’s for people living with obesity with a medical need to lose weight fast.
Thinking about a quick diet? Read the best diet to lose weight first.
Why does the scale drop fast in week one?
That early drop is partly glycogen water. Your body stores some carbs as a fuel called glycogen. One study found it’s stored with three to four parts water.
Eat less and you use that fuel up. The water goes with it.
Think of wringing out a wet towel. It weighs less, but it’s the same towel. The same study links this water to weight swings while dieting, and to fast regain if you load up on carbs again.
So a 3 kg first week doesn’t mean 12 kg by the end of the month. Judge your pace over several weeks, not one.
How to lose weight safely in 4 weeks
Eat about 600 calories a day less than your body needs. An NHS London guide says that’s how to hit 0.5 to 1 kg a week.
On average, women use around 2,000 calories a day and men around 2,500. So average needs minus 600 is about 1,400 or 1,900. Your own needs may differ.
Six NHS steps for your 4 weeks
- Eat about 600 calories a day less than your body needs.
- Swap sugary drinks for water. Add lemon or lime if you don’t like the taste.
- Don’t skip meals. You might snack more because you’re hungry.
- Cut down on alcohol, which is high in calories.
- Get active for 45 to 60 minutes a day. You can split it into shorter bouts.
- Set realistic goals and weigh yourself regularly to check how you’re doing.
Sources: NHS; NHS tips; NHS London
Don’t cut much harder without medical support. The same NHS guide warns your body may not get all the nutrients it needs.
For meals and moves, see a weight loss meal plan and walking to lose weight.
How much weight can you lose in 3 months?
At the NHS pace, about 6 to 12 kg in 12 weeks. That’s simple maths, not a promise. Weight loss usually slows down over time.
12 weeks at the NHS pace
- 1
Weeks 1 to 4
About 2 to 4 kg. Part of week one is water.
- 2
Weeks 5 to 8
About 4 to 8 kg in total.
- 3
Weeks 9 to 12
About 6 to 12 kg in total if the pace holds. Weight loss usually slows.
- 4
Later on
Programmes typically reach their most weight lost at 6 to 8 months.
Sources: NHS; Hall, Lancet
A review in The Lancet found weight loss programmes typically hit their most weight lost after 6 to 8 months. Weight then slowly comes back over the years.
Want a 12-week structure? The free NHS Weight Loss Plan app lets you set a 12-week goal and a daily calorie target. To see how much your loss is worth, use our weight loss percentage calculator.
Keep your strength as you go with keeping muscle while losing weight.
When to speak to a GP
Have a medical condition, a special diet for your health, or an eating disorder now or in the past? Talk to a GP before you start. Also see a GP if:
- You keep losing weight without changing your diet or exercise. Go as soon as possible if you have other symptoms too.
- Your BMI (body mass index, a score of your weight for your height) is in the overweight or obese range and you want help to lose weight.
- Your BMI is overweight or obese and your waist is more than half your height, or obesity runs in your family.
- Your BMI is overweight or obese and you have pre-diabetes, diabetes, high blood pressure, joint pain, high cholesterol, sleep apnoea (breathing that stops and starts as you sleep) or heart or circulation disease.
- You have, or think you may have, an eating disorder, such as binge eating.
Fast weight loss can bring on gallstones. Get an urgent GP appointment or call 111 if you have tummy pain that lasts longer than 30 minutes.
Call 999 or go to A&E if you have sudden, severe tummy pain, or pain that spreads to your back and you’re being sick. The same goes for a very high temperature or feeling hot, cold or shivery, or yellow skin or whites of your eyes.
Check where you stand with a healthy weight for your height or waist to height ratio.