Women and fasting

Can women fast? Or is it – as many people still claim – somehow dangerous for them?
Not surprisingly, the use of fasting for weight loss has a long history. It makes sense that if you do not eat, you are highly likely to lose weight. Which makes it even more surprising how much people fear missing even a single meal, let alone fasting for a day or more.
Some fear that fasting (not eating) will ultimately lead to a ‘starvation mode’ and actually make you fat. That’s kind of like saying that splashing water on your head will dry your hair. Kind of a Bizarro world. It is a mistruth used to instill fear.
Tales of people ‘ruining’ their metabolism abound. Food companies, of course have eagerly ‘educated’ medical professionals about the dangers of missing meals and the safety of eating sugar. Nobody makes money when you skip meals.
A long history of fasting


Fasting appeared in the medical literature over 1 century ago. Interestingly, they describe ‘professional fasters‘ who would fast for specific periods of time for exhibition. One professional faster went for 30 days and drank a quantity of his own urine (definitely not recommended!!!).
Talk about being starved for entertainment. Kind of like watching paint dry. This was depicted in Franz Kafka’s short story “A Hunger Artist”. Fasting for entertainment was popular from 1883-1924. My guess is that it really is not that entertaining.
In the early 1900s, Drs. Folin and Denis described fasting as ‘a safe, harmless and effective method for reducing weight of those suffering from obesity’. Great. That’s exactly what we need. Something safe, harmless, and effective.
The fact that fasting has been performed (mostly for religious purposes) for several thousand years only reinforced the long history of safety. It’s hard to argue that fasting is dangerous if people have been doing for 5,000 years. May as well argue that using soap is dangerous. Yet, myths about the dangers of fasting are everywhere.
By the early 1950’s, Dr. W. Bloom reignited interest in fasting as a therapeutic measure mostly using shorter fasting periods. However, many longer periods were also described in the literature.
Fasting for women?
Dr. Gilliland reviewed fasting in the revival of the 1950’s and 1960’s and reported his experience with 46 patients “whose reducing regime started with a standard absolute fast for 14 days”. Whoa. I love that. When I tell people to fast for more than 24 hours their eyes just about bug out of their head. These people had a ‘standard’ fast that lasted for 2 weeks! And that was just the beginning!
Of these, there were 14 males and 32 females. This is important because I constantly get questions about whether fasting works for females. This is primarily, I think due to a post found online that’s been viewed close to 100,000 times. What she wrote in 2012 is this – “Intermittent fasting and women: Should women fast? The few studies that exist point towards no.”
Nothing is further from the truth. There are hundreds of studies spanning over 100 years and clinical experience spanning 5,000 years that point to the fact that women and men respond more or less equally except in the underweight situation.
This is an easy problem. Should anybody who is seriously underweight, fast? Uh, no. You don’t have to be a genius to figure that out yourself. If you are malnourished or underweight and fast, you could become infertile, yes.


Consider the past 2,000 years of human history. Are Muslim women ‘exempt’ from fasting? Are Buddhist women ‘exempt’ from fasting? Are Catholic women ‘exempt’ from fasting? No. So we have millions of person-years of practical experience with women and fasting. And there are no problems in 99.9% of cases.
In our own clinic, where we’ve treated close to 1,000 patients, I have noticed no significant difference between men and women. If anything, the women tend to do better. Men, it seems, are sometimes just big babies. I will mention here, too, that the highest success rates come when husband and wife do it together.
Exceptions and problems
However, pregnant women are, in fact ‘exempt’ from fasting in almost all human religion. As are children. In both situations, this makes entirely logical sense. These people have greater growth demands, and human populations have always acknowledged this.
Let’s be clear here. This point is made that several problems come up with fasting in women. Well, they come up with men and fasting, too. Sometimes women don’t lose weight the way they want. Well, that happens with men, too. The problem of amenorrhea arises when body fat is too low. Yeah, that’s not a problem we treat with fasting.
If amenorrhea or any other problems appear during fasting – stop immediately. That’s your body telling you you need more nutrients. And what about eating disorders? This come up more with women due to the perception that they are more likely to have eating disorders. But that is not gender specific either. if you have an eating disorder, do not fast. It does not matter what gender you are.
Back to the study
Funny enough, 2 patients asked(!) to be readmitted for a second 14 day period of fasting because they wanted better results. Did it work? Was there ever any doubt?
Average weight loss was 17.2 pounds (8 kg) in 14 days. This is in excess of the roughly 1/2 pound (0.2 kg) per day of fat loss seen in more prolonged fasting. This indicates that some of the initial early weight loss is water weight. This is confirmed by the rapid regain of weight upon refeeding.
It is important to understand this in order to avoid the disappointment that often accompanies the weight gain upon eating again. That quick weight loss and regain is water weight and not a reflection that the fasting ‘failed’. 44 of 46 patients completed the 2 week fasting period. One developed nausea and one simply decided against it and dropped out.
That’s a 96% success rate even for a regimen as long as a 2 week fast! This is our clinical experience as well. People always think they cannot do it without ever having tried it a single time. Once we start with fasting, patients in our Intensive Dietary Management (IDM) program quickly realize that it’s actually quite easy.
However, after the fasting period, patients were instructed to go on a low calorie diet. This was terribly unsuccessful. 50% of patients did not adhere to this diet over the ensuing 2 year follow up period. Instead of applying successful intermittent techniques, they returned to the unsuccessful constant energy restriction we discussed at the last post.
The key point here is that the natural rhythm of life is Feast and Fast. There are times that you should feast (weddings, celebrations), and there are times that you should fast. Intermittent. To constantly restrict calories for years on end is unnatural and ultimately worse, unsuccessful.
Was it hard? In fact, Dr. Gilliland describes a ‘feeling of well being’ and ‘euphoria’. Hungry? Well, no. “We did not encounter complaints of hunger after the first day. We did not meet anorexia.” These experiences were echoed by other researchers of the time.
Dr. Drenick, from the VA centre in Los Angeles, also wrote extensively about therapeutic fasting. His experience was published in 1968. This was a time of renewal of interest in fasting for weight loss. He published his experience of 6 men and 4 women (yes, again there were women in the study). Did it work? In a word, yes.
Should women fast? Yes
Should men fast? Yes
More
Intermittent fasting for beginners
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Dr. Fung has his own blog at intensivedietarymanagement.com. He is also active on Twitter.
His book The Obesity Code is available on Amazon.
This is well established.
The difference with HFLC fasting is that a) it's low carb so your insulin is low so your body will be able to access the fuel in your fatcells and b) because your body gets fuel (from your fatcells) and does *not* get the signal that it's starving, it will *not* lower your metabolism.
Now, in stead of making fun of people, why not simply... explain this to them?
I had a partial hysterectomy about 10 years ago due to uterine fibroids. I kept my ovaries and cervix. I also have Hashimoto's Thyroiditis. I have been strictly following a LCHF diet for just over 4 weeks. In my fourth week I completed a 22 hour fast and several shorter fasts of about 16-18 hours. On my second day of LCHF, I experienced cramping and a very light discharge for about 24 hours. Today, on my 33rd day of LCHF, the cramping returned but this time with a true menstruation. The 30-day timing is highly suspect as it resembles a regular monthly cycle...is this common? Other women eating LCHF report in the Ketogenic Success Facebook group that irregular monthly bleeding is common and attribute it to fat cells releasing estrogen. Most say that their cycles return to normal after 3-6 months. What is the cause? Should I be concerned? Otherwise, I'm feeling fantastic. I'd love to know your thoughts on this. Thank you so much!
1) Some women (men too, to a lesser degree) have very distorted body images and are at risk for developing eating disorders--or already have them. Prolonged fasting and failure to "feast" intermittently with nutritious foods can feed in (no pun intended) to this problem. I'm beginning to see some of the IF group forums start to read like the forums that encourage anorexia and bulimia in teens. The type of fasting Dr. Fung recommends is healthy fasting, but it can be twisted into some very unhealthy practices.
2) When menses cease as a result of fasting, as Dr. Fung says "Stop Immediately". But some people don't stop. One member of a FB fasting group (named after Dr. Fung and supposedly quoting him) claimed Dr. Fung said that "there's nothing wrong with not menstruating regularly--it's a natural form of birth control". IMHO, that is just wrong. Healthy women of child-bearing years menstruate regularly as they should. As a person with PCOS who struggled long and hard against insulin resistance to be able to menstruate regularly and have normal fertility, I don't see this as something to be taken lightly. When your body shuts down fertility, other harm is occurring. Some women will sacrifice their own health for the almighty scale, and it's easy to do by taking fasting too far.
Many women fast successfully, but some may ignore their body's signals and take it too far.
If you are a member you can direct your question to dr Fung here (after july 4.)
http://www.dietdoctor.com/member/ask-dr-jason-fung
I am 37year old mum of 2 and i weigh 61.5kgs at a height of 168.91cm.
However after 4 months of personal training i saw absolutely no change in my weight nor muscle definition nor inches lost. My holistic dr said that my body fat has gone up to 28% and my muscle mass has dropped!!!! However differnt centres/gyms show diff results!!!
Past 3 days i have revamped my intermittent fasting with only 2 meals a day. No more snacks. I break my fast at 1pm with lunch followed by dinner at around 7.30pm or later depending on my schedule.
My goal is to get to a min 21%body fat or less. I run (love it) 3xweek and do yoga and some resistance training on the other days.
With too many unsolicited opinions and mostly all personal trainers being nutrition experts i am hoping to seek the right guidance from you in my goal of fat burning and lowering my body fat
Am i on the right track? Pl pl help.
I’d like to address another poster who said she/he was aware of some obese people who fast for long periods of time, eat and haven’t lost any weight. IMHO, most of these people obviously break they “fasts” with high carbs and sugar, i.e., pancakes, bread, potatoes, soda, beer, high protein, dairy, etc. There is no way in May, that these people are practicing a keto lifestyle accompanied with their “fasting”. The reason I can opine is experience. My mother (died at over 400 lbs) would eat like this. She wouldn’t eat until noon and when she did, it was a very high carbohydrates with heavy protein and milkshakes, and alcohol. She tried low fat, but that lasted as long as the food on her plate before she was reaching for a sugary soda.
I’m moving onto week 3 of the 16:8 fasting protocol and while I have not weighed myself yet, I am noticing my body is redistributing my composition, which is fine with me. I’m going to wait until I complete my first 6 week mark to weigh-in. My starting weight was 182.3 lbs at my last medical check up. My goal weight (or appearance is fine with me) is 130-135 lbs. I am 62 years old and 5’6”.
My take on Dr. Fung is a huge round of applause for his knowledge of newfound health discoveries and if his colleagues are still touting archaic theories that have kept us in poor health, on medications that are quickly being recalled, due to a million and one side effects, almost as quickly as they’re introduced on tv, instead of recommending a person with type 2 diabetes simple change the way they eat, they push a pill at them that may kill them.
Rock on, Dr. Fung!
I would really like to try this. It makes so much sense. I have similar stats. What exactly is the 16:8 fasting protocol. Would love some help. I'm low carb, high protein, low fat at the moment.
Karen
Weight loss and metabolic disorders are not so simple.
What is likely is that the people you are referring to, either leave their bodies malnourished because they are so ashamed of their size that they do not eat at all- and so their body stores all energy it can as fat.
Also- after decades of being told obesity is caused by excess fat, these people eat once a day, a low fat meal- which is the opposite of what you should do when LCHF IF.
Years and years of contradicting medical and nutrition advice and compounding societal pressure to look a certain way has absolutely demolished any self worth, motivation and drive of countless people struggling with understanding their own metabolism and why they are actually obese.
Extended fasting doesn't always work well for everyone. The fact that you got cold and lost your period are concerning signs. Dr Fung says people should attempt longer fasts under the supervision of their doctor, especially if on any kind of medication. If you are stalled, check out our top weight loss tips.
https://www.dietdoctor.com/how-to-lose-weight
Dr Fung recommends doctor supervision for any longer fasts.
I just released 44 pounds of fat, eating a vegan whole food plant based SOFAS free diet. SOFAS Free is: No sugar, oil, flour, alcohol or salt. After 4 months I started adding salt because I seem to have an electrolyte imbalance. Other than that, this lifestyle has been very successful for me. It took just 7 months to lose the weight, and I have kept if off for 3 months so far. The way I lost the last 8 pounds was I incorporated IF 18:6, and then relaxed it to more like a 16:8, and love it. The program I follow was created by some medical doctors whom I respect and have believed. I have also read lots of science on the subject, and it all seems legit. Plus it worked for me.
However.... the pesky electrolyte imbalance is concerning. It causes me to go from loving all the whole foods I am eating, to all of a sudden, not finding them appetizing or tasty. Sometimes I get nauseas. It could last 1-2 days, and then it goes away. The nausea was so bad one time, that I was vomiting for close to 24 hours and went to the ER. They said I was low on potassium, but that was to be expected after vomiting 24 hours. Is a mineral imbalance the cause of this? Or could it be hormonal? I had been previously diagnosed with Hashimoto's. It all didn't add up, though. I was eating tons of potatoes and sweet potatoes and oat groats, all very high in Potassium. I also added a Potassium supplement, just in case that was the cause. I also take a magnesium supplement, and was using salt. Then I realized it could be some other mineral that was causing an electrolyte imbalance. I tried drinking an electrolyte drink the next time I felt the symptoms coming on, and sure enough, that seemed to work!
However, still concerned that this happens, as it never did before I was eating this way. It has occurred another 6 times or so, but always kept in check with the electrolyte drinks.
Since I was diagnosed with Hashimoto's several years ago, and had hoped to see those numbers improving or reversed when I got my blood work done 2 months ago, but the numbers did not improve.
I am 57, female, and my weight averages between 115-120 pounds now. I have not ever had a successful "diet" experience previously, and am so thrilled that this worked so well for me to take the weight off quickly.
Previously I did practice juice fasting with the Master Cleanse, which I did 4 times a year for 15 years. I loved how I felt on the fasts, but realize that since I was consuming maple syrup, I was not going into Ketosis, and not unlocking the stored fat as energy. Instead, I was shrinking the fat cells with each fast (which lasted between 18-28 days typically) and dropping about 20 pounds, but then putting the 20 pounds back on by the time it was time for my next juice cleanse to begin. I now know this was unhealthy, and I stopped doing this 4 years ago. Since that time, the weight was back on, and I was carrying an extra 45 pounds.
I have been vegan for 4 years, no oil for almost one year. I am excited to try the low carb high fat way of eating, because of the way you present the information. Previously I was not open to it at all. However, your explanations seem very compelling and valid. Also, I must admit that I do miss some of eating some of the foods I will now be able to eat on a low carb, high fat program. But still, I don't understand how these two lifestyles can be so opposite to one another, and yet both get great weight loss results.
One thing those doctors talk a lot about, is that while low carb/keto/paleo diets do allow folks to shed weight quickly, they are not sustainable over the long-run. They state that that way of eating does not provide enough fiber, and that it is much more protein than humans need. BUT, the MOST COMPELLING thing they say is "The Fat you Eat is the Fat you Wear!" That is the biggest hurdle for me. I apologize for giving such a rambling and detailed history. I am hoping that you or some of your readers will be able to help me rectify this in my own mind as I figure out what foods to eat when I am not fasting.
And what caused the electrolyte imbalances?? I'd really like to understand that. I was vegan for years before going SOFAS free. Never had that happen before.
By the way, I decided to jump in with both feet!! I am 52 hours into my first water only fast. I will break the fast with breakfast tomorrow morning. I think I will do the alternate day eating with regular 36 hour fasts initially, in order to take full advantage of the Autophagy and heal from the Hashimoto's and tighten up the excess skin from the weight loss, and benefit from the other anti-aging effects. So far, I feel amazing!!!
I do fully understand the concept of not having insulin in the blood will release the stored fat to be burned as energy. I learned that from you Dr. Fung! It makes sense. And yet it does conflict with my own experience of losing fat while eating lots of Sweet potatoes, oat groats, legumes and fruit, and tons of veggies. No sugar, no oil, no nuts or nut butters, no processed foods, I know I lost fat because my shape changed for the better as I got smaller. Thus, I would really like to sort out my confusion.
I would love to hear from you, Dr. Fung, or anyone who has come upon this lifestyle with a similar background as mine, who can offer me some more insight. Thank you all so much for this group!!!
Blood could come from anus or urethra and be seen in the toilet. Regardless of where the blood is coming from, you need to be evaluated!!
This is one reason that Dr Fung recommends medical supervision for longer fasts. Please check in with your doctor for diangosis and treatment, if necessary.
Unexplained bleeding that lasts longer than a day or two should be checked out by your doctor. Medical questions and concerns are why Dr. Fung recommends medical supervision for longer fasts.