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Intermittent Fasting for Women

intermittent fasting for women

Navigating Intermittent Fasting Schedules for Women

As May marks Women’s Health Month, Lumen recognizes that knowledge is power when it comes to women's health. With the research we have today, the nutrition paradigm is shifting from the concept of calories in, and calories out; to the quality of food you should eat, and, importantly, when you should eat.

In recent years, intermittent fasting has emerged as a trending and widely searched diet due to its success in aiding weight loss and other health benefits. Many experts in the scientific community would agree and have pointed to the benefits of the fast (1).

However, whether you're a newbie or a seasoned faster, women have distinctive hormonal and metabolic variations that might pose unique health challenges when trying to lose weight. And despite their best efforts, traditional dieting and exercise might not be enough for them to reach their goals.

intermittent fasting for women weight loss

Following evidence-based strategies and learning from this women's guide to intermittent fasting, you'll have more insights into finding the optimal intermittent fasting schedule that works for your biology. 

Let's dive in

What is Intermittent Fasting?

Intermittent fasting is the process of alternating eating and fasting for a certain period of time. There are different intermittent fasting methods, including calorie restriction and fasting-mimicking diets (2).

Intermittent fasting has gained more traction in the health community because of its numerous health benefits for your body and metabolism.

Studies have shown that when we fast, we can improve insulin sensitivity, reduce inflammation, and aid in weight loss. Intermittent fasting is also a more flexible and sustainable approach to weight loss compared to other diets and is an effective tool for women looking to improve their overall health and well-being.

The Physiology Behind Intermittent Fasting and Metabolic Flexibility

Intermittent fasting is a great strategy, if the timing is personalized to your unique physiology. "Everyone's metabolism is unique", says Mia Dige, Metabolic Coach and Personal Trainer, "and its ability to switch between utilizing glucose and fatty acids as energy sources might differ."

When you’re in a fasting state, your body shifts from using glucose as the primary source of energy to using stored fat, generating the metabolic switch from carb burn to fat burn. When you're fasting, your body still requires energy, but since there is a window of no food, your body turns to the calories it needs from your storage systems - glycogen and body fat.

Let’s look at the various stages of how the body responds to fasting. In the early phases, blood sugar levels drop, lowering insulin and leptin levels, while increasing glucagon and growth hormone.

These changes stimulate glycogen breakdown to produce energy and maintain your blood sugar levels in healthy ranges (4).

intermittent fasting benefits for women

However, during a prolonged fasting period, the body releases stress hormones, such as cortisol, in response to the perceived lack of energy intake. These stress hormones can push the body into a state of carbohydrate metabolism, where it prioritizes burning carbohydrates over fats for energy.

This shift towards carbohydrate metabolism is due to the body's attempt to preserve its fat stores if the fasting period continues for an extended time.

Cortisol, the primary stress hormone, increases glucose production by stimulating gluconeogenesis, a process where the liver then creates glucose from non-carbohydrate sources, such as amino acids from muscle protein breakdown.

This increased glucose production can lead to the body relying more on carbohydrates for energy and less on fat stores, which may counteract the potential benefits of fasting.

Several factors affect the transition of the body’s fuel source while fasting, including your:

  • Metabolic flexibility toward fat.
  • Length and timing of your fast.
  • Glycogen storage at the start of your fast.
  • Activity level during fasting.
  • Stress levels.
  • Sleep quantity and quality.
  • Monthly cycle and hormone balance.
  • Medications, diseases, and illnesses.

Remember: Before you begin fasting, it’s best to consult a healthcare professional or nutrition expert to help you determine what fasting approach is optimal for your specific needs.

Intermittent Fasting Schedule for Women

Intermittent fasting is beneficial to women’s health - it helps balance several hormones that are essential to weight loss. The three most widely used intermittent fasting regimens are the time-restricted (16/8 method), the 5:2 method (fasting two days a week and eating the other five), and the alternate-day fasting (you eat one day and fast the next) (3).

Let’s take a closer at each of these and their benefits and disadvantages.

The time-restricted (16/8) method consists of fasting for 16 hours of the day and eating within an 8-hour window. It is the simplest to do, and the most flexible and appropriate for women of all ages.

This method promotes weight loss, improves glucose levels, and reduces inflammation. However, it may be difficult to stick to because it can increase hunger and cravings during the fasting period.

"I found that when I fasted past 16 hours, my Lumen levels start to increase. This is my body signalling that it's going into stress mode. Without the biofeedback, I would never have known."
Susan, 45, California

The 5:2 diet consists of eating normally for five days and then reducing calorie intake for the other two days. While this approach may help with weight loss and insulin sensitivity, it requires you to have discipline and develop a weekly meal plan. Additionally, it may cause hunger and irritability on fasting days.

The alternate-day fasting consists of fasting every other day. Multiple studies (5) conducted by Patterson et.al, found that alternate-day fasting resulted in weight loss as well as reductions in glucose and insulin concentrations.

On the other hand, the challenge with this approach is that you may lack consistency which could result in miscalculating fasting days, and hunger and irritability may also occur. Tracking your fasts with biofeedback would help you keep on track.

Lumen is an eye-opener. Use this tool to fuel your body the way it needs to help you succeed with your own goals. We've got this!
Kait, 46, Chicago

Intermittent Fasting During Your Cycles - Featuring Expert Cynthia Thurlow, NP

Regardless of which fast you choose, select the one that will be the most beneficial for your health goals, and remember that there is no one-size-fits-all solution.

Part of setting up an intermittent fasting plan is based on whether you are monthly cycling, in perimenopause, or menopause, says Cynthia Thurlow, NP, and author of Intermittent Fasting Transformation. She adds, "your metabolism speeds up and slows down predictably across the month - because of this, it's important to change what you eat, do intermittent fasting, and increase the intensity of your workouts each week. All of these actions optimize your metabolism."

If you have a 28-day cycle, the first 3 weeks of your cycle are the best times to fast. Your hormones are more stable, it's a great time to decrease insulin, reduce inflammation, and activate autophagy (your body's process of reusing old and damaged cell parts).

According to Cynthia, fasting during the five to seven days preceding your menstrual cycle may unknowingly lead to the depletion of nutrients and hormones necessary in the luteal phase.

"With your hormones in harmony, fasting helps accelerate your metabolic rate—which also allows you to maintain a healthy weight."
Cynthia Thurlow, NP, and Intermittent Fasting Expert

If you're experiencing perimenopause, it's important to integrate fasting into a balanced lifestyle. This means getting good-quality sleep of 7-9 hours, managing your stress levels, and eating nutrient-dense meals. 

If you're menopause and beyond, you can pursue intermittent fasting with few restrictions and time constraints. Cynthia adds, 'intermittent fasting can help slow down the aging process, because it regenerates your entire system, starting with your cells and mitochondria. It also helps reduce hot flashes and other uncomfortable symptoms'.

fasting diet for women

How to Get Started with Intermittent Fasting

Intermittent fasting can be challenging, but it’s simple - and you've probably instinctively done it before when you skip breakfast or dinner.

For beginners, it's best to start gradually. Selecting the fasting method that best suits your health needs is also important. This can be made easier by using intermittent fasting insights suited for your metabolism.

Next, make a plan. Create a grocery list, you can use this one as a guide, with the items you will need for the week, and develop a meal plan to ensure you stay on track.

During your eating window, select foods to support your hormones, feed your microbiome and encourage metabolic flexibility. You can do this by focusing on eating essential nutrients focus on eating high-quality protein, carbohydrates, and fats to help you stay full and energized throughout the day.

Our Lumen metabolic coaches recommend:

    • Avoid processed foods and those high in sugar that cause your blood sugar to spike and then crash.
    • Using a personalized nutritional app to find foods that you should eat when getting started.
    • Stay hydrated by drinking plenty of water and consuming fruits and vegetables
    • Try to stay away from fruit juices, sodas, and other sugary drinks.
    • Incorporate movement and exercise into your daily routine.

intermittent fasting schedule for women

What is the best intermittent fasting schedule for weight loss?

There is not a one-size-fits-all recommended intermittent fasting schedule for weight loss, but rather it should be tailored to the individual. To find the best schedule for you, consider your health status (those with type 2 diabetes should avoid long fasting periods such as 24-hour fasts), your current work schedule, and your appetite throughout the day. Measuring your metabolism will give you a clearer idea of how your body is responding so you can optimize your fast for the best results. 

Tips for Success and Overcoming Common Challenges

To help you succeed with intermittent fasting, including how to ease into it, stay motivated, and track your progress, our metabolic coaches recommend:

Start Slowly

  • When you're new to intermittent fasting, it's important to ease into it slowly. This will help you avoid feeling overwhelmed or experiencing negative side effects like headaches or dizziness. You can begin by fasting for a shorter period of time, such as 12 hours, and gradually increase the fasting period as your body adapts.

Stay Hydrated

  • During the fasting period, it's important to stay hydrated by drinking plenty of water. This will help you avoid feeling hungry and keep your energy levels up.

Eat Nutrient-Dense Foods:

  • Choose nutrient-dense foods that will give your body the nutrients it needs. Focus on eating lean protein, whole grains, fruits, and vegetables to keep you full and satisfied.

Track Your Progress:

  • Tracking your progress will help you stay motivated. It's important to keep a record of your fasting and eating patterns. You can use a journal or an app to track your meals, fasting periods, and weight loss progress. This will help you identify patterns and adjust your approach as needed.

Incorporate Active:

  • While intermittent fasting can help you lose weight, staying active is important to maximize the benefits. Incorporate regular low to medium intensity exercise into your routine, such as walking, running, or strength training, to boost your metabolism and support your weight loss goals. Comparing Lumen Levels pre and post-fasts can also help you identify if you've had a successful fast.

Benefits of Personalized Intermittent Fasting

By utilizing real-time biofeedback, you can effectively evaluate whether you are overfasting and potentially hindering your progress toward your health goals. These insights can help prevent your fasting from working against you.

"Fasting is a great tool if the timing is personalized. Women have different physiological responses, health conditions, and lifestyle factors that influence the effectiveness and safety of intermittent fasting regimens."
Marine Melamed, R.D. Nutritionist at Lumen

The optimal fasting duration varies for each individual, and no one-size-fits-all solution exists. Tailoring your intermittent fasting plans to suit an individual's unique requirements is essential to maximize benefits and reduce potential risks. 

intermittent fasting for women metabolic quizintermittent fasting for women metabolic quiz

Frequently Asked Questions about Intermittent Fasting for Women

Is intermittent fasting healthy for women?

  • Intermittent fasting can help women balance hormones that are essential for initiating weight loss along with providing other benefits such as reduced inflammation and improved heart health. However, IF focuses mainly on adjusting eating times and not on diet quality which is an essential part of a healthy lifestyle [7, 8, 9].
  • Intermittent fasting (IF) combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Overweight or obese adults that are intermittent fasting, compared to energy-restricted dieting, resulted in similar insulin resistance and similar changes in lean mass and fat.
  • Therefore, overweight and obese women can benefit from intermittent fasting. However, the focus of IF should be on the timing of eating rather than on which foods are eaten. Therefore, some people may not achieve a desirable diet quality when following IF.

Under what circumstances should women not fast?

  • Women with a history of an eating disorder, pregnant, breastfeeding, underweight, or women with a clinical condition such as diabetes should consult their doctor about intermittent fasting implications.

What are the effects of over-fasting for women?

  • Overfasting can lead to overeating after we break the fast, which will negatively impact your weight management. It can also have a subsequent effect on overall calorie intake. A very low-calorie intake is not well-tolerated by some individuals. For example, a highly calorie-strict diet can impact bone mass through inadequate calcium intake. Additionally, too few calories can also cause disturbances in the monthly cycle.

Can I exercise while fasting?

  • Yes, it is possible to exercise while fasting. However, it’s important to stay hydrated and not overwork your body. Ideally, the best time to exercise is according to how you feel and what you're used to, so keep duration and intensity in mind.

Can I drink coffee or tea during my fasting window?

  • Yes, you can drink unsweetened coffee or tea during a fast

Can I combine intermitted fasting with carb cycling?


Although intermittent fasting can be challenging, it can offer many health benefits, including weight loss, improved insulin and glucose levels, and reduced inflammation, as well as potential improvements for those with hormonal issues.

By restricting certain foods on specific days, you can build discipline and establish a long-term, sustainable way of living a healthier and well-balanced life. If you are looking to lose weight or improve your health, intermittent fasting is something to consider.

Disclaimer for Intermittent Fasting

Everyone has different physiological needs, health conditions, and lifestyle factors that can affect your intermittent fasting regimens. It is important to consider your individual needs to maximize the benefits while minimizing potential risks. Remember to be kind to yourself as you begin to change your lifestyle and health goals.

If you're pregnant or breastfeeding, underweight, or suffering from a preexisting condition or chronic stress or eating disorder, consult a professional physician before starting any type of fast.


      1. Cienfuegos S, Corapi S, Gabel K, Ezpeleta M, Kalam F, Lin S, Pavlou V, Varady KA. Effect of Intermittent Fasting on Reproductive Hormone Levels in Females and Males: A Review of Human Trials. Nutrients. 2022 Jun 3;14(11):2343. doi: 10.3390/nu14112343. PMID: 35684143; PMCID: PMC9182756.
      2. Patterson RE, Laughlin GA, LaCroix AZ, Hartman SJ, Natarajan L, Senger CM, Martínez ME, Villaseñor A, Sears DD, Marinac CR, Gallo LC. Intermittent Fasting and Human Metabolic Health. J Acad Nutr Diet. 2015 Aug;115(8):1203-12. doi: 10.1016/j.jand.2015.02.018. Epub 2015 Apr 6. PMID: 25857868; PMCID: PMC4516560.
      3. Soliman GA. Intermittent fasting and time-restricted eating role in dietary interventions and precision nutrition. Front Public Health. 2022 Oct 28;10:1017254. doi: 10.3389/fpubh.2022.1017254. PMID: 36388372; PMCID: PMC9650338.
      4. Tinsley GM, La Bounty PM. Effects of intermittent fasting on body composition and clinical health markers in humans. Nutr Rev. 2015 Oct;73(10):661-74. doi: 10.1093/nutrit/nuv041. Epub 2015 Sep 15. PMID: 26374764.
      5. Trepanowski JF, Canale RE, Marshall KE, Kabir MM, Bloomer RJ. Impact of caloric and dietary restriction regimens on markers of health and longevity in humans and animals: a summary of available findings. Nutr J. 2011 Oct 7;10:107. doi: 10.1186/1475-2891-10-107. PMID: 21981968; PMCID: PMC3200169.
      6. Vasim I, Majeed CN, DeBoer MD. Intermittent Fasting and Metabolic Health. Nutrients. 2022 Jan 31;14(3):631. doi: 10.3390/nu14030631. PMID: 35276989; PMCID: PMC8839325.

Lumen Editorial Desk & Reviewed by: Marine Melamed, R.D. Nutrition at Lumen

Marine is a registered dietitian with a passion for well-being, health and metabolism. She started her career as a clinical dietitian, opened her private practice to accompany patients from various backgrounds in their health journey, and is now providing nutrition support for Lumen’s customers.