It's no secret that people who menstruate often find themselves craving sweets or carb- and fat-loaded delights just before the onset of their period. Now, a new research has found that these food-related desires might be linked to insulin sensitivity.

The study, published in Nature Metabolism, found that insulin sensitivity -- the response of your cells to the hormone insulin -- varied throughout the menstrual cycle. These fluctuations were at their highest in the days leading up to ovulation and dip to their lowest levels in the days following the onset of menstruation.

Insulin, often referred to as the body's blood sugar regulator, is a chemical messenger that makes cells absorb glucose from the bloodstream, giving them energy to function. Researchers revealed that low insulin activities in women, without prediabetes or diabetes, led to an increase in their blood sugar levels, which caused an increase in food cravings.

Another study in August had revealed that blood glucose levels peaked right before the onset of periods and dipped just before ovulation.

When insulin sensitivity is high, glucose is seamlessly transferred into the cells. In contrast, low insulin sensitivity, often known as insulin resistance, occurs when cells don't respond optimally to the hormone, leading to a buildup of glucose in the bloodstream. Cravings for food increase when the blood glucose levels are highest.

The increase in blood glucose levels due to insulin resistance deprives cells of the energy they need to function. This can lead to prediabetes, a condition that may increase the risk of developing type 2 diabetes.

During the study, researchers assessed insulin sensitivity in women with natural, healthy menstrual cycles. They used a nasal spray to administer insulin and observed how the hypothalamus responded in both the days before ovulation (follicular phase) and the lead-up to the menstrual period (luteal phase).

It was found that in lean women, brain insulin action boosted peripheral insulin sensitivity during the follicular phase, but didn't have the same effect during the luteal phase.

The researchers caution that further research is needed to confirm their findings, as the study was carried out in only 11 women.

Experts said the findings of this small scale study explain a fairly common phenomenon among women where they experience hunger right before their period. It also offered insights into why their metabolism slowed down, and why weight gains were more likely during this period.

"This is an interesting finding — diabetics have reported cyclical changes in their blood sugar management for many years [...] It is great to see some research into this at last!" Sally King, a postdoctoral fellow in menstrual physiology dept. Of Women and Children's Health, King's College London, who was not part of the study told Medical News Today.

"The methodology of this study was too limited to definitively conclude that insulin sensitivity is reduced during the luteal phase of the menstrual cycle," said Dr. Kara McElligot, obstetrician-gynecologist and NAMS-certified menopause practitioner, who was not involved in the study.

She cautioned that while this study provided some compelling information, it was not enough to prove that the conclusions were true.

Şebnem Ünlüişler, a genetic engineer at the London Regenerative Institute, who was not part of the study, said that variations in insulin sensitivity throughout the menstrual cycle could potentially affect metabolism and body weight.

"Women might find it beneficial to adapt their diet and exercise routine according to their menstrual phase," she added.

"These studies highlight the intricate relationship between hormonal fluctuations and metabolic health in women. Understanding these dynamics may lead to more targeted interventions for managing appetite, weight, and overall health during the menstrual cycle."