Intermittent fasting for women

Over the last 12 months, intermittent fasting (IF) has gained immense popularity as a dietary strategy, especially among women. With the promise of improved hormonal health and weight management, it’s no wonder many are curious about this eating pattern. Intermittent fasting involves cycling between periods of eating and fasting, and it's not about what you eat but rather when you eat. This article explores how intermittent fasting specifically affects women, including its benefits, challenges, and practical tips for success.

What is intermittent fasting?

Intermittent fasting is not a diet in the conventional sense but rather an eating pattern. Some popular protocols which you might have come across include:

• 16:8 method: Involves fasting for 16 hours and eating during an eight-hour window. For example, eating only between noon to 8pm.
• 5:2 diet: Involves eating normally for five days a week while restricting calorie intake (usually to 500-600 calories) on two non-consecutive days.
• 24-hour fasts: Involves fasting for a full day, typically once or twice a week. For example, you might skip dinner on Monday night and then not eat again until Tuesday evening.

Fasting may improve health and longevity by influencing various metabolic processes. The benefits can include improved insulin sensitivity, enhanced fat oxidation, and triggering autophagy (the body's way of cleaning out damaged cells). During periods of fasting, insulin levels drop, which facilitates fat-burning and improves metabolic health.

What are the benefits of intermittent fasting for women?

Research suggests that women may experience different effects from intermittent fasting compared to men, largely due to hormonal fluctuations. Women have unique hormonal cycles influenced by oestrogen and progesterone, which can impact their responses to fasting.

Hormonal health

Intermittent fasting can help improve hormonal balance by regulating insulin and cortisol levels. A study published in The Journal of Clinical Endocrinology & Metabolism found that intermittent fasting improved insulin sensitivity, which is crucial for reducing the risk of type 2 diabetes.

Weight management

Intermittent fasting can aid in weight loss and fat reduction without the need for calorie counting. A meta-analysis found that intermittent fasting led to significant weight loss, particularly for those struggling with obesity. Fasting encourages mindful eating, allowing women to focus on nutrient-dense foods rather than restricting calories.

Cognitive and mental health

Fasting has been linked to improved brain health. A study in Nature Reviews Neuroscience indicated that intermittent fasting may enhance brain function by promoting neurogenesis and reducing oxidative stress. Female clients often report improved mental clarity and reduced brain fog when practising intermittent fasting.

Longevity and cellular repair

One of the most exciting benefits of intermittent fasting is its potential to promote longevity through cellular repair. Fasting activates autophagy, a process where the body cleans out damaged cells, leading to improved overall health and longevity.

Unique considerations for women

Hormonal fluctuations

Women’s hormonal cycles can significantly impact their experience with intermittent fasting. Research suggests that women may respond better to fasting during the follicular phase of their menstrual cycle (after menstruation) when oestrogen levels are higher. Conversely, during the luteal phase (before menstruation), women might experience heightened cravings and fatigue, making fasting more challenging. Dr Mindy Pelz, in her book Fast Like a Girl, emphasises the importance of aligning fasting practices with the menstrual cycle for optimal results.

Potential risks

While intermittent fasting can be beneficial, it is essential to approach it cautiously. Some studies indicate that extreme caloric restriction can lead to menstrual irregularities, particularly in women who are already sensitive to energy deficits. Therefore, women should be mindful of their caloric intake and listen to their bodies. I always recommend engaging a nutritional therapist to support you when you introduce intermittent fasting.

How to break your fast: Why breaking the fast correctly matters

Breaking a fast appropriately is crucial for maintaining energy levels and preventing overeating. In my clinic, I have observed that the key to successful and effective intermittent fasting is actually how you eat when you are not fasting. This observation is backed by a large study published in Nutrition Journal which demonstrated that a well-structured meal after fasting helps stabilise blood sugar levels and promotes satiety.

Focus on protein intake

Protein is essential when breaking a fast, especially for women. Consuming protein-rich foods after fasting will promote muscle synthesis and increase feelings of fullness, reducing the likelihood of overeating later in the day. In her book Eat Like a Girl, Dr. Mindy Pelz discusses how protein should be a cornerstone of post-fasting meals to maximise benefits.

Good sources of protein include:

• lean meats
• eggs
• dairy
• legumes
• plant-based proteins like tofu and quinoa

A well-balanced post-fasting meal might consist of grilled chicken with quinoa and vegetables or a protein-rich smoothie with spinach, berries, and a scoop of protein powder.

How to approach intermittent fasting safely as a woman

Start slow

I recommend that you begin with shorter fasting windows, gradually increasing as your body adapts. For instance, you might start with a 12-hour fast and work your way up to 16 hours.

Listen to your body

Pay attention to hunger cues and energy levels. Fasting is not a one-size-fits-all approach, and it’s essential to adjust based on individual needs.

Sync with your menstrual cycle

It is important to adjust fasting protocols based on different phases of the menstrual cycle. Women may benefit from longer fasting periods during the follicular phase and shorter fasting periods during the luteal phase.

Eat healthily

Focus on consuming nutrient-dense foods to avoid deficiencies and to maintain hormonal balance. Incorporate healthy fats, proteins, and fibres to support overall health.

Balance with exercise

Pair fasting with appropriate physical activity. Low-intensity workouts like walking or yoga may be more suitable during fasting periods, while high-intensity workouts can be scheduled around eating windows.

Intermittent fasting can offer numerous benefits for women, including improved hormonal health, weight management, and enhanced cognitive function. However, it’s essential to approach fasting mindfully, considering individual hormonal cycles and dietary needs. If you are considering intermittent fasting, it can be helpful to seek professional guidance to ensure your success.

References:

• Longo, V. D., & Mattson, M. P. (2014). Fasting: Molecular Mechanisms and Clinical Applications. Cell Metabolism, 19(2), 181-192.
• Tinsley, G. M., & La Bounty, P. M. (2015). Effects of intermittent fasting on body composition and clinical health markers in humans. Nutrition Reviews, 73(7), 7-23.
• Mattson, M. P., et al. (2017). Impact of intermittent fasting on health, aging, and disease. New England Journal of Medicine, 381(26), 2541-2544
• Mattson, M. P., et al. (2018). Impact of intermittent fasting on health, aging, and disease. Nature Reviews Neuroscience, 19(1), 55-73.
• Madeo, F., et al. (2019). Caloric Restriction Mimetics Against Age-Associated Diseases. Nature Reviews Molecular Cell Biology, 20(12), 635-654.
• Gonzalez, M. C., et al. (2018). Effects of menstrual cycle phase on exercise performance and the menstrual cycle: A review. Journal of Science and Medicine in Sport, 21(1), 89-94.
• Pelz, M. (2022). Fast Like a Girl: A Woman's Guide to Using the Healing Power of Fasting to Get Healthier, Weight Loss, and Gain Energy.
• Pelz, M. (2023). Eat Like a Girl: The Essential Guide to Healthy Eating for Women.