Obesity related complications

Obesity related complications

Obesity is much more than just excess weight. It is associated with over 200 complications affecting an individual’s health, various organ systems and medical specialties.1 While some complications are more sensitive to weight loss than others, a weight loss of as little as 5% has significant health benefits, and a weight loss of 10% or more can further enhance these benefits and provide additional weight-loss related improvements to health.2-8

Click on any of the complications below for more information on their association with obesity and the impact of health.


Cardiovascular disease – hypertension, dyslipidaemia and heart failure

Association with obesity

Cardiovascular disease is the leading cause of mortality in people with obesity.9 There is clear association between BMI and hypertension, dyslipidaemia and heart failure. For example, the prevalence of hypertension increases with increasing BMI,10 whereby people with a BMI of 25.0–29.9 kg/m2 are 3 times more likely to develop hypertension than individuals with a normal range BMI.10  With higher BMI, the risk of hypertension increases, even among individuals within the “normal” and mildly “overweight” BMI range.10

Impact on health

For people with obesity and stage 1 hypertension, the first ACC/AHA recommendation is to treat patients by reducing weight through lifestyle modifications, pharmacological treatment and/or bariatric surgery.11 These findings indicate that weight loss is important for the prevention, as well as the initial treatment, of hypertension.


Pre-diabetes and type 2 diabetes

Association with obesity

Men and women living with obesity are almost 7 and >12 times more likely to develop type 2 diabetes than individuals without obesity respectively.12

Impact on health

For individuals with pre-diabetes, treatment through weight loss, not only reduces the risk of developing diabetes,2 but can also take diabetes into remission.13 Weight loss studies show that over an average follow-up period of 2.8 years, the risk of developing diabetes can be reduced.2 Importantly, in patients with obesity and pre-diabetes, even 10 years after initial weight loss, and despite weight regain, there is a significant reduction in the risk of developing type 2 diabetes compared to those individuals who didn’t lose any weight.14 Similarly, weight loss studies after bariatric surgery found that individuals had lower 2- and 10-year incidence rates of diabetes, hypertriglyceridemia, and hyperuricemia following weight loss surgery.15



Association with obesity

Men and women with obesity are >2 and 2 times more likely to develop osteoarthritis than someone without obesity, respectively.12 Weight loss is the first recommendation in any guideline for knee osteoarthritis.16

Impact on health

Weight has been strongly associated with prevalence of knee osteoarthritis, with a 15% increase in risk per unit increase in BMI.5 In these cases, weight loss is recommended as part of management and also leads to symptom relief and improves function, functional status and reduces pain.6


Polycystic ovary syndrome (PCOS) and infertility

Association with obesity

The pathophysiology of PCOS is complex and remains largely unclear, however the condition has been found to be intricately linked with obesity. Between 60% and 80% of women with PCOS have obesity, and it is considered to contribute and exacerbate complications of PCOS,17 including developing insulin resistance and pre diabetes/diabetes,18 heart disease,19 and fertility problems or infertility.18

Impact on health

Weight loss is the primary recommended treatment for PCOS,20 improving clinical features and long-term metabolic health in women with PCOS. Some of these improvements include lowered insulin levels,21 decreased insulin resistance,18 decreased androgen levels and risk factors for cardiovascular disease and type 2 diabetes.19 Importantly, menstrual cyclicity, ovulation and fertility22 have been shown to improve following weight loss.18


Sleep apnoea

Association with obesity

Although prevalence rates of obstructive sleep apnoea syndrome are difficult to determine, approximately 40% of people with obesity are thought to have obstructive sleep apnoea.23

Impact on health

Weight loss should be considered as an intervention for patients with obesity, as losing weight may help people with obesity sleep better by easing obstructive sleep apnoea symptoms. Studies suggest that 7–11% weight loss may decrease apnoea and hypopnoea index in individuals.24

BMI and risk of mortality

Research shows that a high BMI is associated with a decreased life expectancy of up to 10 years.25 For every 5 kg/m2 BMI increment above the range of 22.5–25.0 kg/m2, there is a 30% increase in overall mortality.25

Adapted from Prospective Studies Collaboration. Body-mass index and cause-specific mortality in 900,000 adults: collaborative analyses of 57 prospective studies. Lancet. 2009;373(9669):1083–1096.


1.   Yuen M, Earle R, Kadambi N, et al. A systematic review and evaluation of current evidence reveals 195 Obesity-Associated Disorders (OBAD). The obesity society 2016 abstract book 2016:92.

2.   Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002; 346:393–403.

3.   Wing RR, Lang W, Wadden TA, et al. Benefits of modest weight loss in improving cardiovascular risk factors in overweight and obese individuals with type 2 diabetes. Diabetes Care. 2011; 34:1481–1486.

4.   Dattilo AM and Kris-Etherton PM. Effects of weight reduction on blood lipids and lipoproteins: a meta-analysis. Am J Clin Nutr. 1992; 56:320–328.

5.   Coggon D, Reading I, Croft P, et al. Knee osteoarthritis and obesity. Int J Obes Relat Metab Disord. 2001; 25:622-627.

6.   Christensen R, Bartels EM, Astrup A, et al. Effect of weight reduction in obese patients diagnosed with knee osteoarthritis: a systematic review and meta-analysis. Ann Rheum Dis. 2007; 66:433–439.

7.    Zelber-Sagi S, Godos J and F S. Lifestyle changes for the treatment of nonalcoholic fatty liver disease: a review of observational studies and intervention trials. Therap Adv Gastroenterol. 2016; 9:392–407.

8.   Glass LM, Dickson RC, Anderson JC, et al. Total body weight loss of >/= 10 % is associated with improved hepatic fibrosis in patients with nonalcoholic steatohepatitis. Dig Dis Sci. 2015; 60:1024-1030.

9.   The GBD 2015 Obesity Collaborators. Health Effects of Overweight and Obesity in 195 Countries over 25 Years. New England Journal of Medicine. 2017; 377:13–27.

10.   Gelber RP, Gaziano JM, Manson JE, et al. A prospective study of body mass index and the risk of developing hypertension in men. Am J Hypertens. 2007; 20:370-377.

11.   Kotsis V, Jordan J, Micic D, et al. Obesity and cardiovascular risk: a call for action from the European Society of Hypertension Working Group of Obesity, Diabetes and the High-risk Patient and European Association for the Study of Obesity: part A: mechanisms of obesity induced hypertension, diabetes and dyslipidemia and practice guidelines for treatment. J Hypertens. 2018; 36:1427-1440.

12.   Guh DP, Zhang W, Bansback N, et al. The incidence of co-morbidities related to obesity and overweight: a systematic review and meta-analysis. BMC Public Health. 2009; 9:1–20.

13.   Lean MEJ, Leslie WS, Barnes AC, et al. Durability of a primary care-led weight-management intervention for remission of type 2 diabetes: 2-year results of the DiRECT open-label, cluster-randomised trial. The Lancet Diabetes & Endocrinology. 2019; 7:344-355.

14.   10-year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. The Lancet. 2009; 374:1677-1686.

15.   Sjostrom L, Lindroos AK, Peltonen M, et al. Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. N Engl J Med. 2004; 351:2683-2693.

16.  Glyn-Jones S, Palmer AJR, Agricola R, et al. Osteoarthritis. The Lancet. 2015; 386:376-387.

17.   Fauser BC, Tarlatzis BC, Rebar RW, et al. Consensus on women's health aspects of polycystic ovary syndrome (PCOS): the Amsterdam ESHRE/ASRM-Sponsored 3rd PCOS Consensus Workshop Group. Fertil Steril. 2012; 97:28-38 e25.

18.   Panidis D, Farmakiotis D, Rousso D, et al. Obesity, weight loss, and the polycystic ovary syndrome: effect of treatment with diet and orlistat for 24 weeks on insulin resistance and androgen levels. Fertil Steril. 2008; 89:899-906.

19.   Wild RA, Carmina E, Diamanti-Kandarakis E, et al. Assessment of cardiovascular risk and prevention of cardiovascular disease in women with the polycystic ovary syndrome: a consensus statement by the Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society. J Clin Endocrinol Metab. 2010; 95:2038-2049.

20.   Garvey WT, Mechanick JI, Brett EM, et al. American Association of Clinical Endocrinologists and American College of Endocrinology Comprehensive Clinical Practice Guidelines for Medical Care of Patients with Obesity. Endocr Pract. 2016; 22 Suppl 3:1-203.

21.   Tolino A, Gambardella V, Caccavale C, et al. Evaluation of ovarian functionality after a dietary treatment in obese women with polycystic ovary syndrome. Eur J Obstet Gynecol Reprod Biol. 2005; 119:87-93.

22.   Dokras A, Sarwer DB, Allison KC, et al. Weight Loss and Lowering Androgens Predict Improvements in Health-Related Quality of Life in Women With PCOS. J Clin Endocrinol Metab. 2016; 101:2966-2974.

23.   Modena DAO, Cazzo E, Candido EC, et al. Obstructive sleep apnea syndrome among obese individuals: A cross-sectional study. Rev Assoc Med Bras (1992). 2017; 63:862-868.

24.   Durrer Schutz D, Busetto L, Dicker D, et al. European Practical and Patient-Centred Guidelines for Adult Obesity Management in Primary Care. Obes Facts. 2019; 12:40-66.

25.   Whitlock G, Lewington S, Sherliker P, et al. Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. Lancet. 2009; 373:1083–1096.

HQ20OB00144, Approval date: December 2020

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