Study question: Do weight management practices differ in women with and without PCOS?

Summary answer: Women in the general population with self-reported PCOS are more likely to be using healthy weight management practices and alternative non-lifestyle measures for weight management than women without PCOS.

What is known already: Lifestyle management is the first-line treatment in PCOS. However, the specific weight management practices used by women with PCOS and their effect on diet and physical activity are unclear.

Study design, size, duration: The study was a population-based observational cross-sectional study involving women in the 1973-1978 cohort (n = 7767 total; n = 556 with PCOS, n = 7211 without PCOS).

Participants/materials, setting, methods: Women with and without self-reported PCOS were included. Self-reported outcome measures included healthy lifestyle-related or alternative non-lifestyle-related (e.g. laxatives or smoking) weight management practices, dietary intake and physical activity.

Main results and the role of chance: Women with PCOS were more likely to be following both healthy [reducing meal or snack size (odds ratio (OR) 1.50, 95% CI 1.14, 1.96, P = 0.004) and reducing fat or sugar intake (OR 1.32, 95% CI 1.03, 1.69, P = 0.027) or following a low glycaemic index diet (OR 2.88, 95% CI 2.30, 3.59, P < 0.001)] and alternative [smoking (OR 1.60, 95% CI 1.02, 2.52, P = 0.043) or use of laxative, diet pills, fasting or diuretics (OR 1.45, 95% CI 1.07, 1.97, P = 0.017)] weight management practices than women without PCOS. In PCOS, the use of a range of healthy weight management practices was associated with increases in physical activity (P < 0.001), diet quality (P < 0.001), percentage protein intake (P < 0.001) and decreases in glycaemic index (P < 0.001), and percentages of fat (P = 0.001), saturated fat (P < 0.001) or fibre (P = 0.003). Use of alternative weight management practices was associated with decreases in diet quality.

Limitations, reasons for caution: Limitations include the use of self-reported data for PCOS, height, weight, diet, physical activity and weight management behaviours.

Wider implications of the findings: In PCOS, we should focus on improving healthy weight practices across both diet quality and quantity, and on assessing alternative weight practices and their potential adverse effect on dietary intake.

Study funding/competing interest(s): L.M. is supported by a South Australian Cardiovascular Research Development Program Fellowship (ID AC11S374); a program collaboratively funded by the National Heart Foundation, the South Australian Department of Health and the South Australian Health and Medical Research Institute. H.T. is supported by the NHMRC. S.A.M. is supported by an NHMRC Career Development Fellowship Level 2, ID1104636 and was previously supported by an ARC Future Fellowship (2011-2015, FT100100581). The authors declare no conflict of interest.

Trial registration number: Not applicable.