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Osteoarthritis and Weight | Does it matter?

Osteoarthritis (OA) is one of the most frequently encountered conditions that we treat as physiotherapists. It is often described as ‘wear and tear’ and is largely associated with the ageing process. You can think of it as the internal equivalent of ‘grey hair and wrinkles’. It is the most common type of arthritis, characterised by pain and joint stiffness. Although the risk of developing OA increases as we get older, it is not inevitable. The pain associated with it can also come and go and doesn’t necessarily get worse with time. This article will address weight and why it matters in the context of osteoarthritis.

Weight as a risk factor for Osteoarthritis

Many risk factors have been identified that increase the chances of a person developing OA. These include (but are not limited to); ethnicity, genetics, diet, previous injury, occupation, biomechanical abnormalities and being overweight or obese.

In this blog, I want to address why being overweight can contribute to the development of OA, and how losing weight can help to manage the symptoms associated with it. You can read more about the other risk factors in more detail here.

Why Weight Matters

Internationally, obesity levels are on the rise, in adults but even more worryingly in children. Being overweight at any age, increases your likelihood of developing OA, particularly in the weight bearing joints such as hips and knees. This likelihood is amplified if you are overweight from a young age.

This is for two reasons. Firstly, the lower limb joints are simply carrying around excess weight for a protracted period of time, sometimes decades.

Secondly, it’s usually the case that heavier people, have relatively less muscle mass. In other words, they’re in poorer physical condition (weight lifters, body builders and front row rugby players aside). Our muscles play a key role in supporting our joints, therefore less strength, results in less stability and more load/stress being transmitted through our joints.

For example, in relation to the knee, it has been shown that increased body weight correlates with both reduced quadricep (thigh muscle) strength and the likelihood of developing knee OA.

Not only does increased weight and reduced muscle mass result in increased chances of developing OA, it is also likely to accelerate the process, resulting in higher levels of pain and disability. 

The Chicken and the Egg

We often find that people with osteoarthritis become stuck in a downward spiral of deterioration. The symptoms of osteoarthritis start (typically pain and stiffness). As a result, levels of activity drop. This leads to weight gain and a deterioration in physical condition, which in turn leads to increased pain…and the cycle repeats itself!

The Good News

It doesn’t have to be this way! It has been proven that losing weight can effectively reduce the symptoms of osetoarthritis.

Every pound lost is an advantage to your joints. Research has shown a 4-fold reduction in the load exerted at the knee for every pound of weight lost. When we climb the stairs, we load our knees with as much as five to six times body weight. Therefore for every two pounds of weight loss, that’s the equivalent of potentially as much as twelve pounds less being loaded through the knee per step on stairs. So if you’ve got a few stones to lose, just focus on losing 1-2 pounds per week. The focus needs to be on sustainable lifestyle changes, not crash dieting. Play the long game!

A heavier person, needs stronger muscles to support their joints and carry themselves around. A lighter person requires relatively less strength. Therefore, if you can lose weight and increase your strength simultaneously, you are likely to experience a quicker/greater improvement.

Can’t exercise due to pain? Don’t worry. It’s been shown that overweight and obese individuals can lose a large amount of weight with dietary restriction alone. Controlling what you eat contributes far more to weight loss than how much you do. This is for several reasons. One of the main reasons is that it is far easier to consume 500 fewer calories, than it is to burn off 500 calories. Also, we often compensate for increased energy expenditure with increased food intake due to an increase in appetite following exercise. This doesn’t mean exercise isn’t important, or doesn’t play a key role in weight loss, just that weight loss isn’t impossible if you are unable to exercise. Of course you will need your calorie intake to reflect your reduced activity levels.

How to Break the Cycle

  1. Start losing weight today!
  2. Come in for an assessment so that we can confirm your diagnosis and start you on some appropriate strengthening exercises
  3. If pain is limiting your exercise tolerance, try using some regular over the counter pain killers such as paracetamol to enable you to exercise.
  4. If you are still unable to exercise despite taking pain killers, injection therapy may help to lessen the pain, providing you with a window in which you can commence strength training.
  5. Do not fool yourself into thinking that being busy equates to exercise! Targeted strengthening exercises are often needed to see a difference.
  6. The body develops compensatory movement strategies to make up for muscle weakness. These develop without realising. So just because you are up and down stairs all day at work, doesn’t mean you have strong quads and glutes. Get a professional opinion regarding appropriate exercises to address areas of weakness.

How to lose weight?

It is beyond the scope of this blog to discuss this in detail, but weight management comes down to a simple equation. Do the calories you consume exceed the number you expend? If you are less active due to joint pain, you need to allow for this in the number of calories that you consume.

To maintain a healthy weight, guidelines recommended that adult men need to consume no more than 2500 calories per day, and women 2000. This number reduces over the age of 65 and again over 75. If you’ve ever tried to count calories, you’ll realise that 2000 doesn’t go a very long way on an unhealthy diet.

It’s thought you need to consume 500 less calories a day (than your present number) to lose 0.5kg/1lb per week. This doesn’t mean that you have to live on salads or commit yourself to the cabbage soup diet. Just simple choices such as one less glass of wine or pint of beer in a day and passing on that extra slice of jam and toast at breakfast all add up to make a significant difference over time.


Being overweight can contribute to the onset and worsening of osteoarthritis over time. Equally, losing weight can reduce the chances of you developing OA, and reduce symptoms after onset.

Exercise can help with weight loss, but it isn’t essential. Healthy food choices are the cornerstone to weight loss. Carrying out a programme of targeted strengthening exercises complements weight loss in terms of managing the pain associated the osteoarthritis.

If you would like an assessment to confirm whether the symptoms you are experiencing are due to OA, click here to book an appointment to see one of our experienced physiotherapists now.