Quick answer: If you have osteoarthritis and are living with overweight or obesity, NICE says losing weight improves pain, function and quality of life, and any amount helps, though losing 10% of your body weight is likely to be better than 5%. Aim to lose weight steadily, about 0.5 to 1kg a week, with a balanced diet and activity you can manage. Free NHS tools and your GP can help, and a dietitian can tailor advice.
Evidence checked on 10 October 2026 against NICE NG226, the NHS overweight and obesity and Better Health pages, Arthritis UK's weight guidance and published trials.
Weight can be a sensitive subject, and many people with arthritis have been told to "just lose weight" without any real help. That is not fair or useful. Losing weight is genuinely hard, and it is harder when walking hurts and fatigue makes cooking difficult. But weight is also one of the few things with strong evidence for easing joint pain, so it is worth understanding why it matters and what support is available.
This guide is about reaching a weight that is healthy for you, which for some people means losing weight and for others means gaining or keeping weight steady.
Why weight matters with arthritis
Osteoarthritis
NICE guidance on osteoarthritis (NG226) names therapeutic exercise and weight management (where appropriate) as core treatments. For people with osteoarthritis who are living with overweight or obesity, NICE says healthcare professionals should:
- advise them that weight loss will improve their quality of life and physical function, and reduce pain
- support them to choose a weight-loss goal
- explain that any amount of weight loss is likely to be beneficial, but losing 10% of their body weight is likely to be better than 5%
Arthritis UK (formerly Versus Arthritis) explains that the force going through your knees when walking can be two or three times your body weight, so even a small weight loss can make a difference to the load on your joints.
Research supports this. In the US IDEA trial (Messier and colleagues, JAMA 2013), adults with knee osteoarthritis and overweight or obesity who followed a diet, with or without exercise, lost more weight and had greater falls in an inflammation marker than those who only exercised, and the diet group had lower compressive forces on the knee. A 2025 systematic review (Asadi and colleagues) found that reduced-energy diets improved pain, physical function and body weight in people with osteoarthritis.
Rheumatoid arthritis, gout and other types
Arthritis UK says being overweight can increase inflammation in the body and is linked with a higher risk of developing rheumatoid arthritis, gout, back pain and osteoarthritis. For people with gout, losing excess weight can help lower uric acid levels. Excess weight also adds to the higher risk of heart disease that comes with inflammatory arthritis.
Before joint surgery
If you are waiting for a joint replacement, your surgical team may talk to you about weight, because it can affect the anaesthetic, wound healing and recovery. Ask what support is available while you wait.
How to check your weight
The NHS uses body mass index (BMI) as a starting point, alongside waist-to-height ratio. You can use the free NHS BMI calculator online.
| BMI (most adults) | BMI (South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background) | Category |
|---|---|---|
| 18.5 to 24.9 | 18.5 to 22.9 | Healthy range |
| 25 to 29.9 | 23 to 27.4 | Overweight |
| 30 or more | 27.5 or more | Obese |
The NHS explains that people from these ethnic backgrounds are at risk of health problems at a slightly lower BMI. BMI cannot tell the difference between muscle and fat, so it is only a rough guide.
Waist-to-height ratio: the NHS says you should try to keep your waist size to less than half your height. Measure around your middle, halfway between your lowest rib and the top of your hip bone.
Setting a realistic goal
- Start small. The NHS says losing just 5 to 10% of your body weight can improve your health. For someone weighing 90kg, 5% is 4.5kg.
- Go steady. The NHS suggests aiming to lose 0.5 to 1kg (1 to 2lb) a week.
- Measure more than the scales. Notice changes in pain, walking distance, stairs, sleep and how clothes fit.
- Plan for plateaus. Weight loss is rarely a straight line. Keeping weight off is a success in itself.
Eating to lose weight
To lose weight, you need to take in less energy than your body uses. The NHS says that on average women use around 2,000 calories a day and men around 2,500, but this varies, and many people with arthritis are less active than average. This guide does not set a calorie target for you; a dietitian or NHS weight management service can help with that.
Practical changes that follow NHS advice:
- Fill half your plate with vegetables or salad. They are filling and low in energy.
- Choose wholegrain starchy foods and watch portion sizes and added fats such as butter and oil.
- Include protein at each meal to stay full and protect muscle. See our protein guide.
- Cut down on sugary drinks, snacks and alcohol. The NHS points out that alcohol is high in calories.
- Read labels and use the traffic-light system to choose foods lower in fat, saturated fat, sugar and salt.
- Plan meals ahead so you are not relying on takeaways on bad days. Our meal plans for arthritis can help.
- Eat mindfully. Sit at a table, eat slowly and avoid eating in front of a screen.
An anti-inflammatory, Mediterranean-style diet works well for weight loss because it is filling, flexible and not overly restrictive.
Approaches to be cautious about
- Very low calorie diets (under 800 to 1,200 calories a day). The NHS says these are not suitable or safe for everyone and should only be followed with support from a dietitian or specialist service.
- Cutting out whole food groups without advice, which risks missing out on calcium, fibre or protein.
- Unregulated "fat burner" supplements or slimming pills bought online, which can be unsafe.
- Fasting if you take medicines that must be taken with food, or have diabetes, without speaking to your healthcare team first.
Being active with painful joints
Activity helps with weight, but it matters even more for your joints, muscles, mood and heart. NICE recommends therapeutic exercise for everyone with osteoarthritis. Arthritis UK notes that adults need at least two and a half hours of moderate aerobic activity a week plus strengthening exercise, but any amount is better than none.
- Low-impact options: swimming, aqua aerobics, cycling or an exercise bike, walking on flat ground, chair-based exercise.
- Strengthening: sit-to-stands, step-ups, resistance bands. Stronger muscles support your joints.
- Start low, go slow: some extra discomfort while you exercise is normal, but pain should settle within a day or so. If it does not, do a little less next time.
- Get help: a physiotherapist can design a programme around your joints. Many areas offer self-referral to NHS physiotherapy and exercise programmes for joint pain.
Exercise alone usually leads to modest weight loss. Combining it with changes to eating works best, as the IDEA trial showed.
Free NHS and local support
- NHS Weight Loss Plan app: a free 12-week plan to help you build healthier habits.
- NHS Better Health: free tools, healthy eating tips, home workout videos and information on discounted weight-loss programmes.
- Local weight management services: the NHS says you may be able to refer yourself; check your GP surgery website or ask reception.
- NHS Digital Weight Management Programme (England): a 12-week online programme for adults living with obesity who also have diabetes, high blood pressure or both, accessed by referral, usually from your GP practice.
- Specialist weight management services: your GP can refer you if you need more support, including dietitian-led programmes.
Services differ in Scotland, Wales and Northern Ireland. Ask your GP practice what is available locally.
Weight-loss medicines and surgery
Depending on your BMI and other health conditions, your doctor may discuss medicines. The NHS lists GLP-1 and GIP medicines such as semaglutide, tirzepatide and liraglutide, which reduce appetite, and orlistat, which reduces fat absorption. They are prescribed alongside diet and activity changes. Our guide to weight-loss injections and arthritis explains these in more detail, including what to tell your rheumatology team.
Weight-loss surgery may be offered if your BMI is 40 or over, or 35 or over with conditions that could improve with weight loss (with lower thresholds for some ethnic groups). This is a specialist decision.
If you lose a lot of weight, tell your rheumatology team, as some medicine doses depend on body weight.
Common barriers and what helps
| Barrier | What may help |
|---|---|
| Pain stops me exercising | Water-based or chair exercise, a physiotherapy programme, and a pain relief review with your GP |
| Steroid tablets increase my appetite | Ask your rheumatology team about the dose and duration; keep filling, lower-energy snacks such as fruit and vegetables to hand |
| Cooking is too tiring | Batch cooking on good days, frozen vegetables, simple meals, and an occupational therapy assessment |
| I eat when I feel low | Talk to your GP; NHS Talking Therapies (self-referral in England) can help with mood and eating habits |
| Poor sleep makes me snack | Work on sleep habits and discuss night pain with your GP |
Keeping weight off
Many people lose weight and then regain it, which can feel discouraging. Things that tend to help include:
- Weighing yourself regularly, as the NHS suggests, so small gains are noticed early.
- Keeping the habits that worked, such as planning meals and keeping active, rather than going back to old routines.
- Planning for flares. When your arthritis flares, activity often drops. Have a list of easy, healthy meals and gentle exercises ready for those weeks.
- Getting support. Friends, family, a weight management group or an app can help you stay on track.
- Being kind to yourself. The NHS reminds us that changing habits and losing weight is not easy and takes time.
If you stop weight-loss medicines, the NHS says you should be offered support to help you stay a healthy weight.
Being underweight is a concern too
Arthritis UK points out that being underweight can be a symptom of some conditions, such as rheumatoid arthritis, and is linked to an increased risk of fractures related to osteoporosis. If your BMI is below 18.5, or you are losing weight without trying, see your GP. A dietitian can help you gain weight in a healthy way.
When to see a dietitian
Ask your GP about a referral to a registered dietitian if you have tried to lose weight without success, have diabetes, kidney disease or another condition affecting your diet, are considering a very low calorie diet, are underweight, or have a history of disordered eating.
When to get medical help
See your GP if you lose weight without trying, as unexplained weight loss should always be checked. See your GP if you think you may have an eating disorder, such as binge eating. Talk to your doctor before starting a weight-loss programme if you have diabetes, heart disease or take medicines that need adjusting. Get same-day advice from your GP or NHS 111 if a joint suddenly becomes hot, swollen and very painful, especially with a fever.
Frequently asked questions
How much weight do I need to lose to help my knees?
NICE says any amount of weight loss is likely to help, but losing 10% of your body weight is likely to be better than 5%. Even small losses reduce the load on your knees.
Will losing weight cure my arthritis?
No, but for people with osteoarthritis who are overweight it can reduce pain and improve function and quality of life. It also helps heart health and some inflammatory conditions.
How fast should I lose weight?
The NHS suggests a steady 0.5 to 1kg (1 to 2lb) a week.
What is the best diet to lose weight with arthritis?
The one you can stick to. A balanced, Mediterranean-style diet with smaller portions is a good choice. A dietitian can tailor it to you.
Can I get weight-loss injections on the NHS?
Possibly, depending on your BMI, other health conditions and local services. Talk to your GP; see our weight-loss injections guide for details.
I cannot exercise because of pain. Can I still lose weight?
Yes. Changes to eating have the biggest effect on weight. Gentle activity, even seated, still helps your joints and mood, and a physiotherapist can help you find what you can manage.
Sources and further reading
- NICE NG226: Osteoarthritis in over 16s – weight management
- NHS: Overweight and obesity
- NHS Better Health: Lose weight
- NHS England: Digital Weight Management Programme
- Arthritis UK: Managing your weight
- Messier SP et al. Effects of intensive diet and exercise on knee joint loads, inflammation and clinical outcomes in knee osteoarthritis: the IDEA trial. JAMA 2013 (PMID 24065013)
- Asadi S et al. The effectiveness of dietary intervention in osteoarthritis management: systematic review and meta-analysis. Eur J Clin Nutr 2025 (PMID 40295866)
Educational information for people in the United Kingdom — not personal medical or dietary advice. Food and supplements can interact with medicines, so check with your GP, pharmacist or rheumatology team before changing your diet significantly or starting a supplement, and ask for a referral to a registered dietitian for individual advice. Charity no. 1218461. Pending clinical and editorial review. If you feel very unwell, call 999 or go to A&E. For urgent advice, contact NHS 111.
Continue with related help
- Weight-loss injections and arthritis — Wegovy and Mounjaro explained
- Weight management evidence — the research in more depth
- Meal plans for arthritis — a practical 7-day plan
- Protein requirements — keeping muscle while losing weight
- Anti-inflammatory diet — the overall eating pattern