Allow me to start by telling you something you have surely heard before. Maintaining your healthy or ideal weight is important for overall good health and to help prevent or manage certain diseases and conditions -- including arthritis. It can help prevent many comorbid conditions, such as heart disease and diabetes.
According to the National Heart Lung and Blood Institute, overweight refers to "having extra body weight from muscle, bone, fat, and/or water". Obesity is defined as having as "high amount of extra body fat".
Weight Control Decreases Risk of Osteoarthritis
Weight control is a known prevention strategy for osteoarthritis. The Primer on the Rheumatic Diseases (Thirteenth edition, page 616) refers to a study by Felson et al. that reported women who lost an average of 11 lbs. decreased their risk of knee osteoarthritis by 50%. Also from Primer on the Rheumatic Diseases, Felson et al. concluded that moderate weight loss of about 10 to 15 lbs. can alleviate symptoms and slow progression of knee osteoarthritis. Messier and colleagues said that each pound lost correlates with a 4-fold reduction in loading forces on the knee when a step is taken.
Weight loss regimens and exercise have been linked to improvement in pain and disability associated with knee osteoarthritis. It has been recognized that weight loss and exercise can be more effective than either alone.
The benefits of weight control do not just pertain to osteoarthritis. Anyone who deals with joint pain, related to any type of arthritis, would benefit from maintaining their ideal weight. Carrying extra weight adds burden to already stressed joints.
How to Determine Your Ideal Weight
One way to determine your ideal weight is to look up your height on the Healthy Weight Table provided by Rush University Medical Center. Another way, is to calculate your body mass index (BMI). BMI has its critics though -- those who point out that BMI does not take into account muscle mass or bone density. Your BMI equals your weight in pounds divided by your height in inches squared, multiplied by 703. BMI between 18.5 and 25 is considered ideal.
Besides BMI, there are other measures that can be used to determine ideal weight, including waist-hip ratio, waist-height ratio, and Body Fat Percentage. The waist-hip ratio is calculated by dividing the circumference of your waist by the circumference of your hips The waist-height ratio is determined by dividing the circumference of your waist by your height. For the waist-height ratio, your waist circumference should be less than half your height. Body Fat Percentage is the weight of your fat divided by your total weight. Many doctor's offices have devices that measure body fat. Also it can be determined using DEXA and bioelectrical impedance analysis.
How to Maintain Ideal Weight
Simply put, a healthy weight is maintained by balancing calories in and calories out over time. More calories in than out results in weight gain. More calories out than in results in weight loss.
The Bottom Line
You can achieve and maintain your ideal weight by eating a healthy diet (if you are overweight or obese, cut daily calories by 500 to lose weight), remaining physically active, and consciously limiting the time you are physically inactive.
Kelley's Textbook of Rheumatology. Elsevier Saunders. Ninth Edition. p. 1647. Accessed 1/16/14.
Primer on the Rheumatic Diseases. Arthritis Foundation. Thirteenth Edition. Accessed 1/16/14.
Aim for a Healthy Weight. National Heart Lung and Blood Institute. December 1, 2012.
How Much Should I Weigh For My Age & Height? Medical News Today. May 23, 2010.
Osteoarthritis: New Insights. Part 1: The Disease and Its Risk Factors. Annals of the Rheumatic Diseases. October 17, 2000.
Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis. Arthritis and Rheumatism. July 2005. Messier et al.