Intermittent Fasting for Women: How Does Affects Hormones and Weight Loss?
Intermittent fasting is hailed as the latest wonder solution to health and weight loss. But is it really that simple?
For men, research shows strong evidence that fasting improves metabolic health, promotes fat burning, and even enhances longevity. However, as is often the case, research on women tells a more nuanced story. The underlying premise of intermittent fasting (IF) is that by not eating for 10–16 hours, your body taps into fat stores for energy. So should we all be taking regular food-free periods?
The Rise of Intermittent Fasting
Intermittent fasting has become a popular method for weight loss. About 10 years ago, the 5:2 Fast Diet claimed it could even reverse Type 2 diabetes. Unlike ‘traditional’ weight loss diets that involve continuous restriction, 5:2 was seen as more manageable since it allowed people to eat normally most days, restricting intake on just two days a week. For long-time dieters, this seemed more flexible and sustainable.
Other common intermittent fasting methods include:
Alternate Day Fasting: Limited calorie intake on fasting days, followed by normal eating on non-fasting days.
Time-Restricted Eating (TRE): Eating within a specific time window each day, such as 16:8 (fasting for 16 hours, eating within an 8-hour window).
Does Intermittent Fasting Work for Women?
While the evidence supporting intermittent fasting for weight loss is positive in men, studies show mixed results for women. Research has shown that intermittent fasting can help men improve insulin sensitivity, increase fat metabolism, and even enhance longevity. However, women’s bodies respond differently due to hormonal fluctuations.
A recent review published in Nutrients (2022) explored the effects of intermittent fasting on reproductive hormone levels in both men and women. The study found that women experienced greater variability in their hormonal responses to fasting, with some showing disruptions to estrogen and progesterone levels. These hormonal changes can lead to irregular menstrual cycles and increased levels of cortisol, which can heighten stress and affect energy levels. The review also highlighted that women are more prone to negative metabolic effects during fasting compared to men, whose metabolic responses tend to be more consistent .
The Hormonal Impact of Fasting on Women
Women’s bodies are particularly sensitive to changes in food intake because of the complex interplay of hormones like oestrogen, progesterone, and cortisol. When fasting, cortisol levels can spike, leading to higher stress and potential disruptions to the menstrual cycle.
Common challenges women face with intermittent fasting include:
Irregular or missed periods
Fatigue and low energy
Higher cortisol levels, increasing stress
Difficulty maintaining hormonal balance
While men tend to see more consistent benefits from intermittent fasting, women may struggle due to these hormonal fluctuations, making it harder to sustain the fasting routine over time.
Is Intermittent Fasting Sustainable for Women?
One of the key attractions of intermittent fasting is its simplicity. Compared to complex diets with specific food restrictions, IF seems flexible—you can choose your fasting and eating windows to suit your lifestyle. Plus, sleeping through much of the fasting period makes it feel more achievable.
However, this simplicity may not hold up for many women. Busy lives, family responsibilities, and work schedules can complicate fasting. For instance, women with irregular work schedules, such as shift work, or frequent travel may find it difficult to adhere to a fixed fasting schedule.
Even more, the rigid structure of IF doesn’t account for daily fluctuations in activity levels. On more active days, women may need more food or more frequent meals, making fasting windows impractical and potentially harmful to energy levels and overall well-being.
Fasting may not fit with family activities
Many diets, including intermittent fasting, take a one-size-fits-all approach, ignoring individual differences in activity levels, lifestyle, and most importantly, gender. What works for men doesn’t always work for women.
For women, a rigid fasting window may not be the answer. Instead, focusing on intuitive eating—listening to your body’s hunger signals and making mindful food choices—can offer a more sustainable, balanced approach to managing health and weight.
Conclusion: Finding What Works for You
Intermittent fasting may work for some women, but it’s not a universal solution. It’s crucial to listen to your body, monitor how fasting affects your hormones and energy levels, and adapt accordingly. If fasting feels unsustainable or causes negative side effects, exploring more intuitive, flexible approaches may be a better fit.
Have you tried intermittent fasting? How has it worked for you? Share your experience in the comments below!
