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What is Intermittent Fasting?
It is considered to be a pattern that cycles between eating and fasting. The most common fast is 16 hours in a 24 hour period however there are many other ways to fast. Intermittent fasting dates back to the days of hunters and gatherers. They didn’t have a constant supply of food so there were periods where they were hunting (fasting) for their food. Intermittent fasting is common among some religions and for spiritual reasons as well. Intermittent fasting for women is different than in men. So keep reading to learn the pros and cons of intermittent fasting for women.
How to get started with Intermittent Fasting
It is recommended to start slow. Studies have shown that just 12-14 hours overnight can yield great metabolic benefits. Then you can gradually increase your fast to 16 or even 18 hours. But listen to your body and pay attention to hunger levels, energy levels, stress, and sleep habits.
Another common way to fast is a 5:2 ratio. Meaning you fast for 2 days with a caloric restriction of 500-600 calories and then continue to a more normal eating pattern the other 5 days of the week. But again, there are many ways to do this. Overall you will more than likely create a caloric deficit which will help with weight loss.
To learn all of the ins and outs of fasting, I recommend The Complete Guide to Fasting book. It will give you everything you need to get started.
Benefits of Intermittent Fasting
Intermittent Fasting has shown many benefits for people trying to lose weight. It has been shown to regulate blood glucose levels, control lipids, decrease the risk of coronary artery disease, manage body weight, and even decrease the risk of some cancers. Another benefit may include boosting levels of HGH which leads to more fat loss and muscle gain.
The New England Journal of Medicine found that in a fasted state, cellular repair occurs which is linked to an increase in longevity, a lower risk of cancer, lower inflammation, and a boosted metabolism. However, more studies in intermittent fasting for women are needed.
Intermittent Fasting has shown that one can boost fat burning after 10-16hrs with no food.
If you choose to try intermittent fasting, the Fit Track Smart Scale is a great tool to track the impact on your body. It stores 13 different metrics so you can see if it’s working for you!
Intermittent Fasting in Women
Personally, I have found more cons to Intermittent Fasting in women than benefits. A lot of it is related to women’s hormones being different than men’s hormones.
First, fasting can increase cortisol levels, which we know as our stress hormone. Higher cortisol levels can lead to blood sugar dysregulation, an increase in insulin sensitivity, lean muscle loss, fatigue, and thyroid dysfunction over time. This can occur in both men and women.
Some women have reported developing binge eating disorders and can lead to other eating disorders. Intermittent fasting in women can lead to metabolic disruption, loss of menstrual periods, and even early-onset menopause.
How Intermittent Fasting in Women causes more Stress on the Body
When you consistently consume less energy than you expend, you’re known to be in a negative energy balance. Being in a negative energy balance is how you lose weight. So it’s exactly what many people try to achieve by dieting. I recommend getting a journal so you can track your times, food intake, energy level, stress levels, etc.
But when it’s extreme or goes on too long in the context of other stressors, it may be to blame for the hormonal spiral we see in some women who fast.
A negative energy balance doesn’t just result from eating less food.
It can also result from:
- poor nutrition
- too much exercise
- too much stress
- illness, infection, chronic inflammation
- too little rest and recovery
Any combination of stressors could be enough to put you into excessive negative energy balance and stop ovulation. For example:
- training for a marathon and nursing a virus
- too many days in a row at the gym and not eating enough to restore glycogen levels
- intermittent fasting and busting your butt to deal with the daily stresses of work, kids, money, activities, etc
Psychological stress can play a role in damaging your hormonal health.
Our bodies can’t tell the difference between a real threat and something imaginary generated by our thoughts and feelings. These “threats” can increase our levels of the stress hormone cortisol. And cortisol? It inhibits our old friend GnRH.
Disrupting GnRH creates a cascade effect that can suppress your ovaries’ production of estrogen and progesterone—hormones that are critical for reproduction. But we will discuss these hormones specifically in a minute.
Why Does Intermittent Fasting affect Men and Women Differently?
We’re not totally sure. But there are a few potential contributing reasons:
1. Women may be more sensitive to changes in nutrient balance than men.
Men and women seem to respond differently when fasting or significantly restricting calories. This may be due to kisspeptin, a protein-like molecule that’s essential in the reproductive process.
Kisspeptin stimulates GnRH production in both sexes, and we know it’s very sensitive to leptin, insulin, and ghrelin—hormones that regulate and react to feelings of hunger and fullness.
Interestingly, females have more kisspeptin than males. More kisspeptin may mean that women’s bodies are more sensitive to changes in energy balance.
Compared to men, fasting more readily causes women’s kisspeptin production to dip. When kisspeptin drops, it tosses GnRH off-kilter and upsets the whole monthly hormonal cycle.
2. Restricting certain nutrients, like protein, may also have different effects on women compared to men.
In general, women tend to eat less protein than men. And usually, women who fast will eat even less protein (because they’re eating less overall). That’s a problem because protein provides amino acids, which are critical for the reproduction process.
If amino acids get too low, it can negatively affect both your estrogen receptors and a hormone called insulin-like growth factor (IGF-1). Both are needed to thicken the lining of the uterus during the menstrual cycle. If the uterus lining doesn’t thicken, an egg can’t implant, and pregnancy can’t occur. Hence, low protein-diets can reduce fertility.
Why estrogen matters so much for a woman’s appetite, mood, metabolism, and body fat.
Estrogen isn’t just for the uterus and reproduction. We have estrogen receptors throughout our bodies, including in our brains, GI tract, and bones.
Change estrogen balance and you change metabolic function all over: cognition, mood, digestion, recovery, protein turnover, bone formation—and maybe most relevant to this discussion—appetite and energy balance.
In the brainstem, estrogens modify the peptides that signal you to feel full (cholecystokinin) or hungry (ghrelin).
In the hypothalamus, estrogens also stimulate neurons that halt the production of appetite-regulating peptides.
Do something that causes your estrogen to drop (like intermittent fasting), and you could find yourself feeling a lot hungrier, eating a lot more than normal, hence defeating the purpose of intermittent fasting.
Read here https://thefitnessmink.com/hormones-affected-by-weight-loss/ to learn more about the effects of weight loss on hormones.
Estrogen also affects fat storage
As you can see, estrogens are key metabolic regulators. Estriol, estradiol, and estrone, also known as estrogenic metabolites, are three different types of estrogen found in the body.
The ratios of these estrogens change over time. Before menopause, estradiol is the big player. But after menopause, estradiol drops, while estrone stays about the same.
The exact roles of each of these estrogens remain unclear. But some theorize that a drop in estradiol may trigger an increase in fat storage.
This could at least partly explain why some women find it harder to lose fat after menopause.
However, that theory may not explain everything. While a drop in estradiol may be linked to an increase in fat storage, it’s probably not the sole cause (and may not be causal at all).
Instead, fat increases around menopause may be due more generally to aging, lowered muscle mass, and changes in appetite (low estradiol is also linked to higher appetite).
So Intermittent Fasting in Women may not be Beneficial
Women’s bodies may just have a greater sensitivity to changes in energy balance.
When our bodies do detect changes, it may disrupt the HPG-axis, and our whole hormonal cycle is thrown off.
This hormonal turmoil can be aggravated further if there are other stressors draining our energy. Such as taking care of kids, working more hours, dealing with a chronic injury, juggling after-school activities, and maybe all at the same time.)
Intermittent fasting may decrease estrogen, and decreased estrogen may increase appetite and fat storage. Making this a not-so-good option for women with PCOS. Read more about weight loss in women with PCOS here https://thefitnessmink.com/how-to-lose-weight-with-pcos/
Intermittent fasting throughout a Woman’s Life
Intermittent fasting in girls and teens
During periods of intense growth, such as childhood and adolescence, fasting isn’t recommended.
Kid’s metabolism is enough to allow them to consume a considerable amount of calories without weight gain, assuming it is a balanced diet and not full of sugar and fatty foods.
As a teenager, it can be a time of intense insecurity of themselves physically and socially, and is often when many young girls consider “dieting.” We want kids to focus on appetite awareness and mindful eating, and prioritizing whole, nutritious foods, not restrict calories.
Intermittent fasting and ovulation
If you’re trying to conceive, intermittent fasting could make things difficult. Fasting can inhibit ovulation. If you aren’t ovulating, no egg gets released. If no egg gets released, it can’t be fertilized.
Most women in the reproductive phase of life do best with moderate, sustainable good nutrition habits. Unless a woman’s getting paid to look or perform a certain way (such as a professional athlete), compromising fertility and hormonal balance may not be worth it.
Like childhood and adolescence, pregnancy is a time of intense growth.
Weight gain is a desired outcome of a developing pregnancy and is a sign of a healthy, growing baby.
Even though weight gain during this time is wanted, many women feel uneasy about the upward-creeping scale. Women who are especially conscious of their appearance or those who wanted to lose weight before pregnancy may still think about weight loss during this time.
Even if weight management is suggested by a medical professional, fasting is not appropriate during this time. Instead of restricting food, focus on eating a more nutritious diet: aiming to get adequate protein, healthy fats, quality carbohydrates, colorful vegetables, and fruits.
Intermittent fasting while breastfeeding
If you’ve had a baby and decided to breastfeed, you already know this is a demanding time for your body: You might still be recovering from childbirth, you’re probably sleep-deprived, and your whole life has been completely turned up-side-down.
During this time, your body needs extra nurturing, extra nutrients, and less stress. For these reasons, intermittent fasting is likely not good for breastfeeding women.
Many moms are concerned about “losing the baby weight,” and may feel pressured and impatient to get their prepregnancy body back. Women can still lose weight during this time, but more moderate approaches are safer and will likely yield better long-term results.
Intermittent fasting in aging women
Puberty, periods, maybe pregnancy, and postpartum. Holy Cow what a twisting and winding roller coaster!! Your hormones and life go from one extreme to another!
Then comes menopause!!!!
Women in this phase may be returning to themselves after decades of being devoted to children, spouses, and careers. Or, they may be busier than ever, taking care of aging parents and young adult kids who are still trying to “find themselves.” Whatever the context, increasing age often triggers a desire to focus on health.
Some women become interested in intermittent fasting because of its association with longevity. Others just want to lose fat in an uncomplicated way. While we don’t have much research on whether or not intermittent fasting is beneficial to women who are menopausal or post-menopausal, we do know that restricting food is also a stressor regardless.
Lower estrogen levels also mean your body has a decreased capacity to deal with stress. So add that to rising cortisol levels, increasing body fat leading to more stress. It can be a vicious cycle. This is where you learn to pick your battles. Of course, we want to be healthy and look good doing it, but at what expense?
So, if you’re a woman in this hormonal phase, try intermittent fasting only if:
- Your stress is low.
- You’re getting quality sleep.
- You’re not tormented by hot flashes and mood swings.
- You don’t have any nutrient deficiencies.
Lol, yeah good luck with not suffering from atleast one of these!
Fasting is a tool, and should never be treated like a rigid diet. For women specifically, there’s a lot to consider before starting intermittent fasting. It is not recommended for women with diabetes, eating disorders or women who are pregnant or breastfeeding.
Start slowly if you do try and pay close attention to your hunger and satiety. If you find yourself starving throughout the day or week, it may be best to resume a more regular eating pattern.
And definitely keep tabs on symptoms such as fatigue, mood swings, hunger, reduced energy, lack of concentration and loss of menstrual cycle. You should feel, energized and satisfied throughout the day, not groggy and hungry.