It’s no secret that men and women respond differently to diet and exercise programs. Intermittent fasting is quickly becoming the hottest trend for achieving weight loss and a host of other benefits. So, we wanted to investigate whether women should follow the same type of intermittent fasting plan as men. Here’s what we found.
Should Women Even Fast?
There definitely seems to be a variety of valid perspectives on this topic, as is the case with most health matters these days! Overall, there doesn’t appear to be any evidence that intermittent fasting is bad for women. Despite this, there are some women who do experience negative effects. It is possible that women will respond better to certain intermittent fasting schedules than others, and we’ll dig into what those schedules are below.
First, let’s review what a typical intermittent fasting plan looks like.
What is Intermittent Fasting?
Intermittent fasting is a practice where you intentionally stop eating for a specific window of time every day or every other day. There are a variety of ways to do it, but the most common is to fast for 16 hours every day while limiting your eating window to 8 hours. We have a handy Beginner’s Guide on intermittent fasting for you here. You can also see some samples of common intermittent fasting schedules here.
A growing number of people are trying intermittent fasting in order to experience its proven benefits, which include:
- Sustained weight loss
- Enhanced energy
- Increased brain health
- Improved cardiac health
- Regulation of blood sugar levels
- Regulation of hormone levels
- Anti-aging benefits
You can read more about the proven amazing benefits of intermittent fasting here.
Intermittent Fasting For Women
When trying to get to the bottom of how intermittent fasting works for women’s bodies, you’ll find that the answers fall into two very distinct categories. There is the science and research, which tells us that fasting is safe and successful for women. Then there are the personal experience testimonials, which tell us that certain intermittent fasting plans can be tough on some women, while other plans seem to work great. We’ll break this information down for you here. At the end of the day, you just need to try what feels right for you!
The Science on Women and Fasting
There are two primary areas of concern that many women have before starting a fasting plan: 1) Is it safe? and 2) Will I get the same benefits that men experience?
Is fasting safe for me?
Probably the most common concern is that women’s hormone levels will be adversely affected by intermittent fasting. Indeed, one rat-based study did show that intermittent fasting can cause hormonal imbalance in female rats. (1)
Scientific research on humans, however, has shown just the opposite. Short-term fasting seems to have no effect on a woman’s hormones or menstrual cycle, and all reproductive hormones should stay within normal levels. (2)
What’s a short-term fast? Anything less than 24 hours. Fasts lasting longer than 24 hours are not recommended for women, as they are likely to start negatively affecting hormone balance.
Caveat: women who already have very low body fat levels are not likely to be good candidates for intermittent fasting. (Neither are men with excessively low body fat!) The fat loss triggered by intermittent fasting can cause a woman with already low levels of body fat to experience amenorrhea (loss of menstrual cycle) or difficulty conceiving. But a woman with normal and healthy body fat levels is not likely to experience any serious changes in her reproductive hormone profile while fasting. (3)
Also, pregnant and breastfeeding women should never fast.
Will I get the same benefits from fasting as men?
Virtually all studies on fasting confirm that men and women both experience the same benefits. In one particular study, men and women were shown to have very similar rates of weight loss during fasting. (4)
Recognized fasting expert Dr. Jason Fung has treated nearly 1000 patients with intermittent fasting, and he concludes that women actually tend to do better than men when it comes to successfully seeing results. In his experience, the highest success rates for weight loss with intermittent fasting actually occur when a husband and wife follow the plan together.
The Personal Experiences of Women and Fasting
A quick Google search will lead you to a catalog of women’s experiences with fasting, which ranges from miraculously healing to downright awful. Of course, just about any diet or fitness plan out there can result in this wide spectrum of experiences. It’s because we’re all so beautifully individual! But we wanted to highlight a few key points to guide you in your decision of whether intermittent fasting is right for you, and which schedule you should choose.
Use a Modified Fasting Schedule
According to the weight of testimonials, women seem to respond much better to intermittent fasting when they adopt shorter fasting windows than men, and stick to an alternate-day fasting schedule. Here’s what that looks like:
On Mondays, Wednesdays, and Fridays, only eat between 10:00am and 8:00pm. That’s a 14 hour fast with a 10-hour eating window. On Tuesdays, Thursdays, and Sundays, you would eat normally.
You might find this method referred to as the “Crescendo Method” of intermittent fasting. It gives your female body a chance to adapt to the new stresses of intermittent fasting, and it is more likely to help you achieve long-term benefits. If you’re following the method for 2-3 weeks and feeling good, you can always add one more day of fasting per week, or maybe try extending your fasting window by one hour for one day per week.
You should always pay close attention to how your body is responding to any changes to your diet or exercise routine. But with intermittent fasting, in particular, you want to keep an eye out for any of these changes:
- Increased stress
- Trouble falling or staying asleep
- Hair loss
- Anxiety or depression
- Low energy
- Slowed digestion
- Muscle pain or increased soreness
- Mood swings
- Loss of sex drive
- Loss of menstrual cycle
- Feeling cold
If you are definitely noticing one or more of these symptoms in a pronounced way, please stop your fasting plan immediately. If you’re starting to feel like any of these symptoms are just starting to happen, you can try to adopt a more conservative and gentle fasting approach. That means taking a couple days off of fasting before trying it again or making your eating window a couple hours longer.
Make Sure You’re Getting Enough Protein
The main reason why intermittent fasting can be trickier for women than men is that of its effect on hormone balance. And one of the key ingredients to keeping hormones balanced is protein!
Eating protein provides your system with amino acids, which are the building blocks of the estrogens (estriol, estradiol, and estrone) in your body. If you’re not getting enough protein and amino acids, your body can’t make enough of these estrogen metabolites. (5)
In general, women tend to eat less protein than men. And when women adopt a shorter eating window, they are more likely to wind up consuming even less protein.
So if you decide to give intermittent fasting a try, it can be helpful to make sure you’re getting a solid helping of high-protein foods at every meal during your eating window (think fish, beans, quinoa, protein shakes). You can also consider taking a BCAA (branch chain amino acids) supplement during your fasting days.
Use Resources and Support Groups
If you’re eager to give intermittent fasting a try but are nervous about what to expect, don’t feel like you are alone! There are quite a few awesome support groups and message boards on Facebook and Reddit. Just search for “intermittent fasting for women” and see which groups appeal to you. It can be very helpful to read through the personal experiences of other women or to be able to reach out to them with questions about your own journey.
To Fast Or Not To Fast: Pros and Cons
In light of this wide range of information, you might be on the fence about trying intermittent fasting. We wanted to put all the pros and cons in one place so you can weigh them and decide for yourself. Good luck!