Nutrition for Lean Women With PCOS

Read any information regarding polycystic ovary syndrome (PCOS) and you will be sure to come across recommendations for weight loss. Indeed, weight reduction can improve both metabolic aspects of PCOS (lowering glucose, insulin, and reduced diabetes risk) as well as reproductive aspects (regulating menstrual cycles and improving ovulation).

But what if you have PCOS and aren’t overweight? High insulin levels can still occur in lean women putting them at risk for type 2 diabetes. Certainly being underweight can affect ovulation as too little body fat can cause menstrual cycles to stop. Weight loss, therefore, isn’t a treatment option for women with PCOS who are lean. So what can be done?

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Here are four tips lean women with PCOS can do to improve their fertility, manage symptoms, and overall improve the quality of their health.

Make Breakfast Your Biggest Meal of the Day

In a study published in Clinical Science, 60 lean PCOS women were randomized into two groups of meal distributions: One group ate a high-calorie breakfast with smaller amounts at lunch and dinner (980 calories breakfast, 640 calories lunch and 190 calories at dinner), and another group that ate later in the day (190 calories at breakfast, 640 calories at lunch and 980 calories at dinner). Those who started the day with the bigger breakfast saw reductions in insulin, glucose, and testosterone as well as increased ovulation rates.

Take Vitamin D

Vitamin D, both a hormone and a vitamin, is showing promise in helping women conceive and reduce the risk for diabetes. An assessment of studies that evaluated the relationship between vitamin D and fertility, published in the European Journal of Endocrinology, showed evidence that vitamin D is involved in female reproduction including IVF outcome and PCOS. The authors suggested that in PCOS women, vitamin D supplementation might improve menstrual frequency and metabolic disturbances.

Vitamin D deficiency is common in women with PCOS. One study in the European Journal of Endocrinology found that the prevalence of vitamin D deficiency was 73% in women with PCOS. Many factors can affect vitamin D status including poor intake of vitamin D foods, sunscreen, and geographical location (northern territories receive less sunlight).

To find out if you need to take vitamin D, contact your healthcare provider or registered dietitian nutritionist.

Don’t Forget Omega-3 Fats

Omega-3 fats may be effective in improving insulin resistance and hirsutism in lean women with PCOS. In a study published in the Journal of Obstetrics and Gynecology, forty-five non-obese women with PCOS were given 1,500 milligrams of omega-3 fats for six months. Reductions in BMI and insulin levels were found along with improvements in LH, testosterone, and SHBG levels.

Plant-based sources of omega-3 fats include avocado, nuts, and seeds. Coldwater fish such as salmon, tuna, and trout are excellent sources of omega-3 fats.

Government guidelines recommend Americans consume two servings of fish each week to obtain the essential amounts of omega-3 fats needed for health. In addition, fish oil supplements may also help to meet the requirements.

Consider Inositol

One of the most widely studied dietary supplements in the PCOS population is inositol. And with good reason: both Myo (MYO) and d-Chiro-inositol (DCI) inositol types have been shown to improve many of the metabolic and reproductive aspects of PCOS. These benefits include improvements to cholesterol, insulin, and androgens. Best of all, MYO has been shown to boost fertility by improving egg quality and restoring menstrual regularity.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Progyny. The link between PCOS and weight.

  2. U.S. Department of Health and Human Services Office on Women's Health. Weight, fertility, and pregnancy.

  3. Jakubowicz D, Barnea M, Wainstein J, Froy O. Effects of caloric intake timing on insulin resistance and hyperandrogenism in lean women with polycystic ovary syndrome. Clin Sci. 2013;125(9):423-32. DOI:10.1042/CS20130071.

  4. Lerchbaum E, Obermayer-Pietsch B. Mechanisms in endocrinology: vitamin D and fertility: a systematic review. European Journal of Endocrinology; 166(5):765-778.

  5. MedlinePlus. Vitamin D deficiency.

  6. Oner G, Muderris II. Efficacy of omega-3 in the treatment of polycystic ovary syndrome. J Obstet Gynaecol. 2013;33(3):289-91. doi:10.3109/01443615.2012.751365.

  7. National Institutes of Health Office of Dietary Supplements. Omega-3 fatty acids fact sheet for consumers.

  8. Unfer V, Facchinetti F, Orrù B, Giordani B, Nestler J. Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials. Endocr Connect. 2017;6(8):647-658. DOI:10.1530/EC-17-0243.

By Angela Grassi, MS, RDN, LDN
 Angela Grassi, MS, RDN, LDN, is the founder of the PCOS Nutrition Center.