Open Access

Obesity: when treating, remember to manage the underlying cause as well

Ian D. Caterson


Professor Caterson is the Boden Professor of Human Nutrition and Director of the Boden Collaboration, The University of Sydney, Sydney, NSW.

Obesity is associated with a range of complications,1,2 and often, in the rush to manage a specific well-recognised disease or condition, the management of the underlying condition – obesity – gets forgotten. In general, the complications of obesity can be categorised under three major headings – metabolic, mechanical and psychosocial. Diabetes, dyslipidaemia and heart disease come under the first heading, arthritis and obstructive sleep apnoea under the second, and then depression, the effects of stigma and a range of social consequences come under the last heading. Cancer can also be considered under metabolic complications, with a range of cancers now recognised as being caused or exacerbated by obesity.3 Can deaths from cancer be prevented by weight loss? Indeed they can. In an early study of 43,457 never-smoking women (over the period 1959–72) any intentional weight loss resulted in a 40 to 50% reduction in mortality from obesity-related cancers.4 Yet we still persist in not managing obesity. It will be interesting to see if management of obesity and overweight can prevent recurrence of treated obesity-associated cancers.

Part 3 of this Obesity Awareness Collection covers obesity associated with cardiovascular issues, osteoarthritis, COPD, reproductive and lower urinary tract complications in men, and male infertility. Osteoarthritis is the second most costly complication of obesity, after diabetes. All of these conditions, and many others, are precipitated or made worse by obesity. However, weight loss can put these obesity conditions into remission. Weight loss can also prevent type 2 diabetes or delay its onset. 


So, we should put the treatment of obesity much higher up on our priority list when managing our patients. We need to diagnose obesity now, not wait eight years before discussing it with patients, set out a management plan and then follow up. We need to diagnose, discuss and direct.5,6 There are a range of interventions that can be used in addition to the usual lifestyle modifications, which have been discussed in Parts 1 and 2 of this Collection. Obesity treatment helps control disease, improves quality of life, is cost-effective and is wanted! 




1.    Bray GA, Kim KK, Wilding, JPH. Obesity: a chronic relapsing progressive disease process. A position statement of the World Obesity Federation. Obes Rev 2017; 18: 715-723.
2.    Jastreboff AM, Kotz CM, Kahan S, et al. Obesity as a disease: the Obesity Society 2018 position statement. Obesity  2019; 27: 7-9.
3.    Lauby-Secretan B, Scoccianti C, Looms D, Grosse Y, Bianchini F, Straif K, International Agency for Research on Cancer (IARC) Handbook Working Group. Body fatness and cancer – viewpoint of the IARC Working Group. N Engl J Med 2016; 375: 794-798.
4.    Williamson DF, Pamuk E, Thun M, Flanders D, Byers T, Heath C. Prospective study of intentional weight loss and mortality in never-smoking overweight US white women aged 40-64 years. Am J Epidemiol 1995; 141: 1128-1141.
5.    Caterson I, Alfadda AA, Auerbach P, et al. Gaps to bridge: misalignment between perception, reality and actions in obesity. Diabetes Obes Metab 2019; 21: 1914-1924.
6.    Rigas G, Williams K, Sumithran P, et al. Misconceptions and barriers to treating obesity in Australia: and ACTION-IO country analysis. Obes Res Clin Pract 2020. In press.