The link between obesity and PCOS

Some people are more predisposed to gaining weight than others as a result of their genetics and underlying medical history. For around 1 in 10 women of reproductive age, one condition that frequently leads to weight gain is polycystic ovary syndrome (PCOS).¹ 

Around half of women with PCOS struggle with obesity, which can make the symptoms of PCOS worse. However, there are ways to manage the symptoms, with research showing that losing even 5–10% of your body weight can have a positive impact. It can improve reproductive health, regulate hormones, boost metabolism, and even support mental wellbeing.¹

But managing weight with PCOS isn’t easy, as the condition is often linked to insulin resistance and increased androgen levels, both of which can make losing weight more difficult. With the right approach, however, it is possible to break this cycle.

The obesity-PCOS cycle

There’s a vicious cycle between PCOS and obesity, whereby they both worsen the outcomes for one another. PCOS is closely linked with obesity, with 38-88% of women with PCOS being overweight or obese.¹ Women with obesity are also nearly three times more likely to develop PCOS than those with a healthy weight, and hence, a cycle occurs whereby one accentuates the other.¹

PCOS can cause symptoms like acne, excess hair growth (hirsutism), hair thinning, and irregular periods, which may lead to fertility issues.² Though not part of the diagnosis, many women with PCOS also experience metabolic problems, which are made worse by obesity.²

The insulin resistance issue

Insulin resistance is a common problem for many women with PCOS, meaning the body doesn’t respond as well to insulin, a hormone that helps manage blood sugar.³ This issue is strongly linked to obesity, and the more weight gained, the worse the insulin resistance becomes.³ In PCOS, the body’s ability to use insulin properly is affected by how it signals to the cells, which can lead to higher levels of insulin circulating in the body as it tries to compensate.³

There are several factors that make insulin resistance worse in women with PCOS. Higher levels of testosterone, both before birth and in adulthood, can contribute, as can lower levels of a hormone called adiponectin, which helps control blood sugar. Studies have shown that even women with PCOS who have a similar weight to others tend to have lower levels of this hormone.³

When obesity is added into the mix, insulin resistance often gets worse, and the body produces more insulin to try and manage it. This extra insulin can lead to higher levels of androgens, which are responsible for many PCOS symptoms like irregular periods, excess hair growth, and acne.³ 

Genetics

Genetics play a significant role in the development of PCOS and its connection to obesity. Studies have shown that certain genetic variants, particularly in the FTO gene (associated with fat mass and obesity), can increase the likelihood of developing PCOS.⁴ The FTO gene was the first to be identified as influencing obesity, with specific variants linked to higher body fat and weight gain. Research in the UK found that women with a certain variant of the FTO gene were 30% more likely to have PCOS, although this risk was partly related to their BMI.⁵ 

PCOS as a risk factor for obesity

PCOS can influence weight gain in several ways, one of which is energy expenditure. Women with PCOS may have lower post-meal energy expenditure, meaning their bodies burn fewer calories after eating compared to women without PCOS.⁶ When combined with the likes of insulin resistance, it becomes apparent that those with PCOS face a number of factors that contribute to the development of obesity, further reinstating the definition of obesity as a disease.

Hormonal factors and obesity in PCOS

Androgens, or male hormones, are often elevated in women with PCOS and can also play a role in weight gain. High levels of testosterone in women with PCOS may promote fat storage, particularly in the abdominal area, which is linked to a higher risk of metabolic problems like insulin resistance and type 2 diabetes.⁷ This hormone imbalance also affects how fat cells function, potentially leading to increased fat breakdown and reduced fat burning, making weight management even more difficult.²

Mental health and weight gain in PCOS

Many women with PCOS experience anxiety, depression, and negative body image, which can make it harder to stick to healthy lifestyle changes like diet and exercise. In fact, women with PCOS have higher rates of anxiety and depression compared to women without the condition, both of which can create barriers to successful weight management and further contribute to weight gain.⁸

The role of physical inactivity

While there is no strong evidence that PCOS directly affects muscle strength or fitness levels, emotional barriers such as low confidence, fear of injury, or lack of motivation can prevent women with PCOS from engaging in regular physical activity.¹ Consequently, this adds even more risk to increased weight gain over time and makes it harder to lose weight.

Losing weight if you have PCOS

The good news is that even modest weight loss can improve insulin sensitivity and reduce the symptoms of PCOS. A healthy lifestyle, including a balanced diet and regular exercise, is key to managing both PCOS and weight. Addressing emotional barriers and seeking support for mental health challenges can also make a big difference. While PCOS can make weight management more difficult, with the right strategies and support, women with PCOS can successfully lose weight and improve their overall health.

The numan take

Addressing obesity in PCOS is far from simple, and often requires a multifaceted approach. Most importantly is your ability to adopt a resilient and driven mindset that allows you to shift your relationship with nutrition and reach out for help when it’s most needed. Remember, obesity is a disease, too, and must therefore be treated as such. 

References

1. Barber TM, Franks S. Obesity and polycystic ovary syndrome. Clin Endocrinol (Oxf) [Internet]. 2021;95(4):531–41. Available from: http://dx.doi.org/10.1111/cen.14421

2. Rasquin LI, Anastasopoulou C, Mayrin JV. Polycystic Ovarian Disease. StatPearls Publishing; 2022.

3. Barber TM, Hanson P, Weickert MO, Franks S. Obesity and polycystic ovary syndrome: Implications for pathogenesis and novel management strategies. Clin Med Insights Reprod Health [Internet]. 2019 [cited 2024 Sep 12];13:117955811987404. Available from: http://dx.doi.org/10.1177/1179558119874042

4. Walley AJ, Blakemore AIF, Froguel P. Genetics of obesity and the prediction of risk for health. Hum Mol Genet [Internet]. 2006;15(suppl_2):R124–30. Available from: http://dx.doi.org/10.1093/hmg/ddl215

5. Barber TM, Bennett AJ, Groves CJ, Sovio U, Ruokonen A, Martikainen H, et al. Association of variants in the fat mass and obesity associated (FTO) gene with polycystic ovary syndrome. Diabetologia [Internet]. 2008 [cited 2024 Sep 12];51(7):1153–8. Available from: https://pubmed.ncbi.nlm.nih.gov/18478198/

6. Robinson S, Chan S-P, Spacey S, Anyaoku V, Johnston DG, Franks S. Postprandial thermogenesis is reduced in polycystic ovary syndrome and is associated with increased insulin resistance. Clin Endocrinol (Oxf) [Internet]. 1992 [cited 2024 Sep 12];36(6):537–43. Available from: https://pubmed.ncbi.nlm.nih.gov/1424179/

7. Xu X, Pergola GDE, Björntorp P. The effects of androgens on the regulation of lipolysis in adipose precursor cells. Endocrinology [Internet]. 1990;126(2):1229–34. Available from: http://dx.doi.org/10.1210/endo-126-2-1229

8. Deeks AA, Gibson-Helm ME, Paul E, Teede HJ. Is having polycystic ovary syndrome a predictor of poor psychological function including anxiety and depression? Hum Reprod [Internet]. 2011;26(6):1399–407. Available from: http://dx.doi.org/10.1093/humrep/der071