Surgery preparation
Losing weight before orthopaedic surgery: benefits and practical considerations
Why weight may be discussed before joint surgery, what improvement may be possible, and why preparation should remain individual and multidisciplinary.
People are sometimes asked to improve their health or reduce weight before hip, knee or other orthopaedic surgery. The aim is to support mobility and reduce modifiable risk—not to blame or create a guarantee of a complication-free operation.
Why weight may be discussed
Higher body weight can increase load through weight-bearing joints and is associated with osteoarthritis. It may also make anaesthesia, positioning, wound care and rehabilitation more complex, particularly when combined with diabetes, sleep apnoea or cardiovascular disease.
BMI is only a screening measure. It does not describe fitness, muscle strength, nutrition, fat distribution or the full risk of surgery, so decisions should not rely on BMI alone.
Potential benefits
- Reduced load on hips and knees may improve pain, gait and daily function for some people.
- Improved blood glucose, blood pressure, sleep and fitness may support anaesthesia and recovery.
- Strength and conditioning can make rehabilitation tasks easier, even if weight changes only modestly.
These benefits vary. Weight reduction cannot remove every surgical risk and should not be presented as a condition for a guaranteed result.
Avoiding unintended harm
- Rapid or poorly supervised restriction may reduce protein intake, muscle mass and nutritional status.
- Pain and limited mobility can make generic exercise advice unrealistic or unsafe.
- Delaying surgery has consequences, including worsening mobility and quality of life.
- A target should be clinically justified, achievable and reviewed with the orthopaedic and anaesthetic teams.
A broader pre-surgery plan
Preparation may include nutrition, strength and balance work, diabetes management, smoking cessation, sleep-apnoea treatment and planning for support at home. A GP, surgeon, anaesthetist, physiotherapist, exercise physiologist and Accredited Practising Dietitian may each contribute.
- Ask what specific risk the proposed target is intended to reduce.
- Ask whether maintaining muscle and protein intake is part of the plan.
- Confirm which movement is safe for the affected joint.
- Check whether the surgical date or eligibility will be reviewed as health changes.