Researchers from the University of Tel Aviv say that women with polycystic ovarian syndrome who control insulin levels – by increasing calories at breakfast and decreasing them at dinner – can improve their fertility.

The research was led by Prof. Daniela Jakubowicz, who notes that most women with PCOS are typically “insulin resistant,” meaning that their bodies produce too much insulin, which eventually goes to the ovaries and prompts the production of testosterone, decreasing fertility.

She explains that doctors oftentimes suggest weight loss for overweight women with PCOS in order to manage their insulin levels, but many women with the condition and fertility issues related to it are not overweight.

In the study, 60 women with polycystic ovarian syndrome and a normal body mass index (BMI) were assigned randomly to one of two groups:

  • Big breakfast group – consumed a 980 calorie breakfast, 640 calorie lunch and a 190 calorie dinner
  • Big dinner group – consumed a 190 calorie breakfast, 640 calorie lunch and a 980 calorie dinner.

Both groups consumed a total of 1,800 calories each day and were tested after 90 days for insulin, glucose and testosterone levels. Ovulation and menstruation information was also analyzed.

Results showed that though neither group experienced a change in BMI, the big dinner group still had high levels of insulin and testosterone.

By contrast, the big breakfast group showed 56% less insulin resistance, as well as a 50% fall in testosterone levels.

Additionally, the reduction of insulin and testosterone levels in the big breakfast group led to a 50% rise in ovulation rate.

Prof. Jakubowicz says this meal plan – eating more in the morning and less in the evening – follows the body’s 24-hour metabolic cycle. She says this diet is not about “weight loss but insulin management.”

For women who have PCOS but are not trying to get pregnant, eating according to the big breakfast guidelines could help with “other symptoms associated with the disorder,” such as unwanted body hair, oily hair, hair loss and acne.

In addition, the researchers say that following the big breakfast diet could prevent the development of type-2 diabetes.

They note that since polycystic ovarian syndrome also impacts in vitro fertilization treatments and increases risk of miscarriage, managing insulin levels could be a way to help with fertility across the board.

Prof. Jakubowicz and colleagues published another similar study recently, which suggested eating a big breakfast of 700 calories promotes weight loss and reduces risks for diabetes, heart disease and high cholesterol – see: ‘Big breakfast healthier than a big dinner’.