Body Weight and Knee Pain

• The force on the knees of overweight or obese patients when walking is 3-4 times greater than their body weight. This is a key factor behind the onset of knee disorders, such as knee pain, stiffness, or impaired function. 
• Being overweight can increase a person’s risk of developing various health issues, such as heart disease, cerebrovascular disease, diabetes, high blood pressure, hyperlipidemia, and osteoarthritis. 

Knee joints are in almost constant motion and are the focal points through which the greatest body weight is placed. This puts them at frequent risk of Fry and other problems, including pain, stiffness, instability, or impaired function. All of this can have distinct and varied causes, such as overuse or strenuous use as observed in the knees of athletes, improper technique employed when lifting heavy objects, sitting or standing for extended periods, joint inflammation, and natural degeneration. However, one of the main causes of these knee complaints is being overweight. 

A number of studies have shown a clear correlation between knee pain and being overweight, most obvious in those defined as obese. Neglected knee issues can lead to chronic pain and other associated complications. Additionally, research has shown that being overweight or obese can increase a person’s risk of joint degeneration occurring in the wrists, hips, and especially knees. 

Body mass index (BMI) is a scale used to analyze the ratio of a person’s weight compared to their height. BMI can be used to determine whether patients aged over 20 are underweight, a healthy weight, overweight, or obese, as follows: 

• BMI less than 18.5 is considered underweight 
• BMI 18.5 – 22.90 is considered healthy 
• BMI 23.0 – 27.5 is considered overweight 
• BMI greater than 27.5 is considered obese 

Increased strain on the knee joint and cartilage protecting the joint: The force on the knees when walking is 3–4 times greater than the person’s body weight. This means that the knees of a person who weighs 80kg will be placed under 240–320 kg of force when walking. This force will increase when engaging in certain activities, such as ascending and descending steps or bending over to pick up an object. An increase in body weight of 10 kg will increase the force placed through the knees by 30–40 kg with every step. This increases the likelihood of knee pain and joint degeneration. Conversely, for every kilogram of weight lost, 3–4 kg of force is lifted from the knees. A weight reduction of 10 kg can result in 30–40 kg of force being taken off the knee joints when walking. Reduced force through the knee joints decreases pain and inflammation, allowing them to function more efficiently. It is easy to see how being overweight can significantly increase the load placed on these crucial joints. 

Knee inflammation: Obesity significantly increases inflammation throughout the body, which is a key factor behind the onset of joint inflammation. Reducing body weight can disrupt this inflammatory process. Some studies have found that those who lost approximately 1 kg per month, over a period of 3 months–2 years, experienced significantly less bodily inflammation than before, resulting in less joint pain such as that felt in the knees. Additionally, an abundance of fat cells can affect chemical levels in the blood, which is another cause of knee inflammation and accelerated onset of osteoarthritis. 

In addition to impact on the knees, being overweight can also increase a person’s risk of developing a host of other health disorders, including heart disease, cerebrovascular disease, diabetes, high blood pressure, hyperlipidemia, and knee osteoarthritis. 

Managing body weight is the best way to reduce the risks associated with being overweight. This can be achieved through regular and appropriate exercise alongside a healthy diet that provides adequate nutrition in line with a person’s unique needs. Studies show that reducing body weight helps reduce the strain placed on the knees, which helps to lessen knee issues and other associated complications, as well as the occurrence of knee osteoarthritis. 

Exercise 

• A regular exercise regime may begin with light exercises that do not place a heavy strain on the knees, such as brisk walking and swimming. These cardio exercises can help the body break down fats while improving endurance, enabling the person to exercise for longer. 
• With regular exercise, the body will become stronger and weight will start to decrease. This can enable the individual to engage in other forms of exercise, such as jogging, aerobic dancing, swimming, and cycling. Muscle resistance exercises, including weight training, can improve the strength of muscles surrounding the knee and thighs. Improved strength in these areas will help extension of the knee while also spreading the load and lessening the impact on the joints. Moreover, weight training focused on other areas of the body will help break down fats and maintain a strong musculoskeletal system that is less prone to deterioration. 
• Stretching exercises are strongly recommended after exercise to improve flexibility, increase range of movement, and ensure muscular balance is maintained. 

Managing food intake 

• While fasting is not advisable, food intake should be carefully managed. Healthy dishes containing the 5 main food groups in moderation are highly recommended. Good proteins can be sourced from chicken breast, fish, skinless meat and eggs, while processed products such as sausages and ham should be avoided. Be sure to consume unrefined carbohydrates, including those found in brown rice and wholewheat bread, while also reducing your intake of refined carbohydrates, desserts, sugar, and sweet drinks. 
• Avoid setting unrealistic weight loss goals: Begin with a realistic goal of losing 5% of your body weight, as this will provide a continuous source of inspiration once achieved. Studies have shown that reducing body weight by 5% or more can significantly improve knee health and reduce pain felt in the joint. 
• Get plenty of sleep: Not getting enough sleep can have a negative impact on body weight. A 2004 study found that people who slept for less than 6 hours a night were up to 30% more likely to suffer from obesity than those who slept for between 7–9 hours a night. More recent studies have also shown a correlation between sleep quality, the hormone responsible for controlling feelings of hunger (ghrelin), and the hormone responsible for letting us know we are full (leptin). Reduced sleep was found to correlate with decreased leptin levels, which resulted in heightened ghrelin levels. Therefore, sufficient rest and sleep are considered essential to maintaining a healthy body weight and reducing the occurrence of knee pain. 

A nutritious diet, appropriate exercise, and getting enough sleep each night can all play a part in helping to reduce body weight and decrease the likelihood of issues affecting the knees. Nevertheless, medical attention should be sought if knee pain, stiffness, or impaired function persist despite losing weight, as a specialist will be required to undertake a thorough diagnosis and prescribe the proper treatment where necessary.