Intermittent Fasting is an increasingly popular tool for weight loss, energy, mental clarity, and more. The idea behind intermittent fasting is pretty straightforward. You eat all your calories in a short amount of time — between the hours of 12PM and 6PM, for example — and then you don’t eat anything for the rest for the rest of the day.
While it’s a simple practice, the health benefits of intermittent fasting are surprisingly robust. Fasting is great for your insulin sensitivity, blood sugar levels, blood pressure, and more. A lot of people also find intermittent fasting makes calorie restriction easier, which helps them meet their weight loss goals.
That said, fasting isn’t for everyone, and some studies suggest that intermittent fasting may affect men and women differently. Some women may want to modify their fasting routine to make sure their hormones and reproductive health stay in good shape.
Here’s a simple guide to intermittent fasting for women, including what intermittent fasting is, the benefits of intermittent fasting, and how, as a woman, you can change intermittent fasting to meet your body’s unique needs.
What is Intermittent Fasting?
Intermittent fasting is easy. You give yourself an eating window each day — say, from noon to 8 PM. During that window, you eat all your food for the day. Outside that time is your fasting window, during which you don’t eat any calories (coffee, tea, etc. are fine).
The above example has an eight-hour window to eat, which means you’re left with a 16-hour fast every day. That’s a popular setup — called a 16:8 fast — but it’s important to remember that there are no strict rules to fasting. You can change your fasting schedule to fit your body’s needs.
Some people fast by skipping breakfast a couple times a week, while others do rigorous alternate day fasting — an eating day, followed by a fasting day– or even fast for several consecutive days. Other people don’t like fasting and don’t do it at all.
Your intermittent fasting schedule is up to you; you can play around with it to see what feels good. You can also check out this beginner’s guide to intermittent fasting for a more in-depth look at how intermittent fasting works.
But why would you want to do fasting at all?
The Health Benefits of Intermittent Fasting
It turns out skipping meals can be great for you. Studies show that intermittent fasting may be good for:
A lot of people find that intermittent fasting helps them eat less. If you only have one or two meals a day, you can make them big and satisfying and still stay in a calorie deficit, which is key for losing body fat.
One of the hardest parts of dieting is going to bed hungry. With intermittent fasting, you can get all that hunger out of the way in the morning, when your energy levels are high. Then you can eat until you’re satisfied in the afternoon and go to sleep on a full stomach.
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As long as you find a rhythm that feels sustainable to you, fasting is an effective way to burn fat and drop body weight[*][*][*].
Fasting activates autophagy, which is like spring cleaning for your cells[*]. Under the gentle stress of fasting, your cells become more efficient, repairing or replacing broken parts. The result is lower inflammation and more effective cellular function across your body[*].
A lot of people report a marked increase in mental function when they fast. While there aren’t any human studies yet, a rat study found that “short-term fasting induces profound neuronal autophagy”[*]. People may enjoy a similar increase in brain autophagy — leading to more efficient brain cell function.
A 2019 study looked at people who fasted from sunrise to sunset for Ramadan. Researchers found that after the fasting period, the participants’ inflammatory markers decreased dramatically[*].
Fasting also pairs especially well with a keto or low-carb diet. Ketosis suppresses hunger[*] which may make it easier to go long stretches without eating.
Does Intermittent Fasting Affect Men and Women Differently?
While intermittent fasting can be great for anyone, regardless of gender, there are a few extra things that women should look out for when they fast.
A lot of the difference seems to come down to hormones. Women go through so much more hormonal variation over the course of a month, and fasting may be particularly difficult during certain parts of your cycle. Things to look out for include:
Loss of your period
While plenty of women thrive on intermittent fasting, others may lose their period when they fast[*].
For some women, low-calorie dieting or prolonged stretches without eating can lower production of two hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), both of which are essential for period regulation[*][*].
If your LH and FSH get too low, you can experience irregular periods or your menstrual cycle can stop entirely.
If you start to see issues with your menstrual cycle, fasting may not be right for your body. Give it a break, and prioritize plenty of nutrient-dense whole foods and healthy fats. They’ll support your hormones and get things back on track.
It’s worth noting that this kind of hormonal imbalance can also happen in response to chronic stress and/or overexercising[*].
Hunger and cravings
During menstruation (the luteal phase of your cycle), a lot of women report intense food cravings [*]. As an interesting aside, one study noted that during menstruation, women craved chocolate more than anything else[*]. You may also burn up to 10% more calories when you’re on your period, which can make you hungrier[*]. Between food cravings, more hunger, and the myriad other symptoms that come with menstruation — fatigue, cramps, and so on — you may want not want to add fasting to the mix.
If you decide to try intermittent fasting, consider taking note of how it feels during different parts of your cycle. You can always adjust your fasting schedule accordingly.
Who Shouldn’t Try Intermittent Fasting?
While fasting is great for a lot of people, it isn’t for everyone. By the same token, there are times in your life when you may not want to fast. If any of the below apply to you, fasting could be a bad idea.
Fasting is mildly stressful, both physically and psychologically. That’s not a bad thing when you’re healthy, but if you’re going through an especially stressful period in your life, adding fasting on top of everything else can cause more overwhelm. Give it a rest and indulge in some stress relief and self-care instead.
While there aren’t specific studies on the topic, fasting probably isn’t the best idea when you’re pregnant or nursing. You have enough to deal with already. Focus on providing plenty of quality nutrition for your child and taking the best care of yourself possible.
If you have a history of binge eating, anorexia, or any other eating disorder, intermittent fasting may not be a good idea. Similarly, if you try intermittent fasting and feel it leads you to develop an unhealthy relationship with food, your best bet is to stop fasting and go back to a more consistent eating schedule.
The Bottom Line: How to Start Intermittent Fasting
While it’s not for everyone, fasting is great for a lot of people. It can be a valuable tool for improving your health and if you’re interested, it’s worth giving intermittent fasting a try.
Fortunately, fasting is simple and free, and you can customize your fasting schedule around any time frame you want. You can be in a fasted state in the morning and have your last meal at night, or vice versa.
This guide to seven different types of fasting has a variety of fasting routines, from gentle fasts that occasionally skip a meal to rigorous multiple-day fasts. Take a look and try something that sounds good to you.
It’s worth mentioning that fasting works particularly well when you’re on a keto diet. Ketosis affects two hunger hormones, ghrelin and leptin, in ways that suppress hunger and make it much easier to go for long periods without eating. Keto is also great for fat burning, preserving muscle mass, preventing insulin resistance, stabilizing insulin levels, and more.
If you’re interested in trying keto as well, this beginner’s guide to keto has everything you need to start today.