intermittent fasting and fertility

Answered on August 19, 2014
Created February 29, 2012 at 3:56 PM

Does anyone have any opinions or know of any research relating to the effects of intermittent fasting and fertility? I am starting to wonder if my IF-ing is hindering my ability to get pregnant. My husband and I are both IF-ing 16/8 with occasional 20 or 24 hour fasts (for the last few months) and follow a paleo diet (for the last year). We've been trying to conceive for 4 months, and although I know that's not a long time, we are only 28 so I kinda thought it would be easier than this. Any thoughts on the matter?



on March 06, 2012
at 04:55 PM

Thank you for asking this! I was wondering the exact same thing and am in almost the same situation as you. I'm 28 and we've been trying for about 5 months. I've laid off IF quite a bit over the last month, but still find myself throwing a fast in occasionally. I guess it's time to completely cut it out for the time being.



on March 01, 2012
at 01:04 PM

Thank you all for your answers! I can't tell you how much I value this community of people :) I ate breakfast today for the first time in months (and it felt great!) Here's to hoping it works!

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5 Answers


on February 29, 2012
at 04:20 PM

I do believe that avoiding fasting, eating more carbs and protein, and being well nourished in micronutrients will help you conceive.

Fasting has a lot of benefits, but it's not good for fertility.



on February 29, 2012
at 04:52 PM

Hi there CMD!

In my opinion, you should try stopping fasting for a while.

There are two sides of course; in general, fasting, if done correctly, and in the right context, does not damage metabolism or make your body go into 'starvation mode', despite all the fearmongering from stuffy experts parroting conventional wisdom. If done the right way, fasting can induce hormesis, reduce general inflammation and detox the digestive system which diverts significant energy to other processes such as the reproductive system. There have been instances when infertile couples have tried fasting and succeeded in concieving. (example: http://www.healthguidance.org/entry/4662/1/Fasting-for-Infertility.html; http://www.fastingconnection.com/forum/Posts-for-The-Fast-Doctor/7585-The-Benefits-of-Intermittent-Fasting)

Its true that one of the things that attracts paleo people to fasting is how it reflects the intermittency of food availability during the time of our evolution as a species.Now during that time, fasting would probably have impacted fertility because if would also create a caloric deficit. In the case of a scarcity in food supply, lower calories could signal a shut-down of the reproductive system since it is not evolutionarily advantageous for a woman to become pregnant in a time of scarcity - in general, offspring is desirable as long as there is a strong chance it will survive and pass on the genes.

However, in our day and age, humans have constant supplies of food so it is possible to undertake intermittent fasting for the benefits of detoxification, hormesis and autophagy without actually creating a caloric deficit if one does not wish to do so. Therefore, I don't think that fasting per se will undermine fertility as long as you continue consuming adequate calories to signal availability of food to the hypothalamus, which in turn will continue producing adequate reproductive hormones. Is this convenient to you?

Furthermore, there are other issues to consider. In particular, stress and cortisol. Have a look at this post by Mark : http://www.marksdailyapple.com/who-should-and-shouldnt-try-fasting/. IF is a stressor. If you are already stressed - chronically, as a lot of people living in hectic cities are - IF could turn from being a hormetic, positive stressor to an addition to ongoing stress, and raise cortisol, which is very negative for fertility.

It is especially worth considering the fact that women are more susceptible to stress/raised cortisol; Martin from leangains actually doesn't recommend women to fast for more than 16 hours for that reason, and to approach fasting with caution in general. I definitely think that going to 20-24 hours is too much, especially if you are trying to concieve.

So a lot depends on you, and if fasting is for you. Are sleeping well, getting plenty of sunshine, rest & play, and are you finding that IFing seems to agree with you? Fasting doesn't agree with me, because I'm easily stressed, and because it makes me loose my appetite which is a problem when you're both active and a jumpy, fidgety person.

There are many benefits to fasting, and it can be a great tool for breaking weight-loss plateaus and, sometimes, sorting out inflammation and illnesses if done with proper supervision and guidance, but you can save these benefits for a later day.

In my honest opinion, since you are finding it difficult to conceive, I would stop doing planned fasts, and stick to eating when hungry - you will still get benefits from avoiding constant snacks and you won't be placing your digestive system under strain. If you wish to fast, keep it to once a week or so, and under 16 hours, but I honestly think that right now, there is no reason for you to fast. Fasting makes it more difficult to get adequate calories and nutrients, since you are essentially going for extensive periods without food. Definitely stop the 20-24 hour fasts.

Also, make sure you are eating nutrient-dense foods, such as shellfish, fish roes, bone broth, grass-fed dairy if you're in the lacto-paleo camp, organ meats and plenty of pastured animals, especially gelatinous cuts such as oxtail. This probably makes you think of all the wierd things people percieved as 'aphrodisiacs' and 'fertility boosters' in the middle ages, but of all the lousy medicine of those days, these actually make sense. Things such as organs and fish roes (essentially eggs - containing all the nutrition needed for the developing embryo) contain a lot of nutrients, vitamins, and minerals and you have to make sure your body knows that plentiful nutrition is available so that you can concieve and carry a healthy child to term.

Also, I'd recommend, very strongly, that you visit Peggy Emch's website: www.theprimalparent.com. She overcame infertility and gave birth to a healthy baby daughter, and her site has plenty of great advice on everything related to parenthood.

I wish you the best of health and luck, and that you will be getting the good news soon!





on February 29, 2012
at 04:08 PM

It may be good for men: http://www.ncbi.nlm.nih.gov/pubmed/3090956

IMO, IF is not a great idea if you are female and trying to conceive. I understand that fasting can be more stressful for some women and you definitely want to keep cortisol levels down.

In a couple more months, if you aren't pregnant, I would suggest preliminary testing to make sure you are ovulating and he has healthy & sufficient sperm. There are at home tests available online.



on August 21, 2013
at 11:29 AM

I see this is a few months old now, but I just thought I'd share this with you because I think its definitely relevant. I use Fertility Awareness to prevent conception, but am hoping to use it to acheive conception after my wedding next year. Each month I've had a fairly regular cycle of 30-31 days with ovulation on Day 16, I've never had any problems with my cycle varying.

This month August, I decided to try IF on the 5:2 regime...I followed this for 3 weeks from the beginning of my August cycle (just happened to coincide), I also had slightly elevated levels of exercise this month in addition (but not excessive - less than 7 hours a week). I did not detect ovultation as usual, and my cycle lasted only 22 days, period being 8 days early, and early periods are indicative of anovulation. The only thing I did really any different this month was trying IF. I can't say with 100% certainty that it was definitely IF which caused me to have an anovulatory cycle, but if you look at the study on rats it makes sense. Although I'm not trying to conceive at the moment I certainly wont be undertaking IF again...because I do want to in the near future and would urge anyone who is TTC to stick to a normal healthy diet and avoid fasting.



on February 29, 2012
at 04:37 PM

My totally unscientific off the wall guesstimate. You're telling your body you're starving by IF'ing. Why would it want to use the resources it has to conceive if it think's your starving?

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