I’ve been doing the ketogenic diet for a couple of weeks now and despite being seemingly the only person to do the ketogenic diet and not lose half their body weight in the first week*, I am loving it. Clear, defined guidelines around what is and is not ‘allowed’ is what I’m all about. My relationship with chocolate (and any source of refined sugar for that matter) was never about ‘moderation’. All or none is how we roll, and at the moment with the keto diet, it’s ‘none’. Plus, I love using the urine test analysis strips which tell you if you are in ketosis or not (is that TMI?). Clearly, it allows me to relive my days of being POAS obsessed and deriving my feelings of validation and success from the drying of urine on a test strip.
What I mean by a keto diet
I’m talking super low carbohydrates; less than 50gms per day (pretty much just incidental carbs you get from eating the non-starchy vegetables that generally grow above the ground like cabbage, broccoli, cauliflower, maybe a few berries and the like), a little bit of a protein and a whole lotta fat. The good fats though, not the nasty transfats that you get in fast and processed foods. I’m also crossing out calorie counting. It’s partly why I love keto (again, she says 2 weeks in).
By the way, did you know that the ‘keto diet’ has been around since the 1920’s and was initially developed as a way to reduce the symptoms of epilepsy in children? … Could Pete Evans actually be right and food is medicine?! (For the record, although I do believe that modification of nutrition and food intake can help improve our lifestyle risk factors that cause us to need medication in the first place I don’t believe food is actually medicine. Or that bone broth can replace baby formula. Or that anti-vaxxing should be a thing).
But what about for women doing IVF?
I know that quite a few women who are trying to conceive at least consider the keto diet. There are reported outcomes of weight loss, reducing insulin resistance and all round improvements including decreased bloating and increased energy levels after all.
I’ve done my PubMed search and like many of the big questions regarding IVF and lifestyle factors, there are very few peer reviewed articles looking directly at the ketogenic diet and its impact on the only outcome measure that really matters in an IVF cycle – the live birth rate. And even less indirect information around if you are not only looking at women labelled as obese or overweight.
There are though a few articles on the impact of ketosis and low carbohydrate diets on PCOS (a major reason why women ultimately need to use IVF) as well as on low carbohydrate diets and its impact on some IVF outcomes such as hormone levels2.
Before getting started
If you see a fertility specialist, thinking about or are about to do an IVF cycle, 1000% speak to your fertility specialist first before starting keto. I’m sure that there are women who have done IVF and started keto the day before their meds started and got 50 Grade A Day 5 Blasts, but seriously, except under medical advice, the day before (or the weeks and longer before) starting an IVF cycle is NOT the time to make such radical changes to your diet. This is especially if you have thyroid issues, participate in regular hard exercise or a few other medical conditions. Again, run it by your doctor.
If you are in the lead up to an IVF cycle and want to make some dietary changes based in scientific research that will optimize your IVF cycle, make sure you have a look at Eat Think Grow. But again, still run it by your doctor and don’t make any huge changes in the short term lead up to IVF.
According to the 2016 US Center for Disease Control’s National Summary Report which evaluates the success rates of IVF cycles, 16% of women doing IVF were diagnosed with ovulatory dysfunction – which is a ultimately why women with PCOS need to do IVF; for various reasons, normal ovulation fails to happen. So, by that thinking, if a ketogenic diet positively impacts PCOS symptoms and supports normal ovulation, than perhaps some women may not need to IVF at all?
The impact of the keto diet on PCOS was investigated back in 2005 by a small study (very small, only 11 participants, only 5 of whom actually stayed the six months to the end)1. At the end of the study, what they found was significant (p<.05) decreases in body weight, percentage of free testosterone, insulin and LH/FSH ratios (testosterone and the LH/FSH ratio can often be higher in women with PCOS which throws the hormone cycle out and contributes to the lack of ovulation that women with PCOS experience). A reduction in all of these markers, as observed, are associated with an improvement in the ovulatory function of women with PCOS.
Although in this respect it seems tick, tick, tick for the keto diet in women with PCOS the authors themselves stated that they were unable to determine if these improvements were a result of weight loss in general (all the women started with BMI’s over 27, which is considered to be at least ‘overweight’) or the direct influence of the specific features related to the keto diet.
Low carbohydrate diet and general IVF outcomes
Melanie McGrice and her colleague, in 2011 examined how low carbohydrate diets can influence the outcomes of obese and overweight women doing fertility treatments, including IVF. A finding of their literature research appears to be that the consumption of low carbohydrate diets can reduce insulin and improve hormonal balance and ovulation function. These are factors which can also improve the quality of an IVF cycle.
There have previously been studies done investigating very low calorie diets (less than 2000kj/day) which have found that women doing IVF and on these diets had high attrition rates and low fertilization rates. Clearly, this is not what any woman doing IVF wants. As McGrice explains, the authors hypothesized that it may be the impact of ketogenesis causing this result. When the authors3 went and did another study, this time ensuring higher protein and less severe calorie restriction (around 5000kJ/day in the 2 months prior to IVF) this same negative impact was not reported. But the subjects were also consuming around 130gms of carbs a day and 23gms of fibre, so is generally not a low carbohydrate diet and ketosis was unlikely. So maybe there is something in that ketosis may have a negative impact on the egg quality?
Conversely and although not directly IVF related, there is early evidence that suggests the ketogenic diet may increase mitochondrial function. Mitochondria is often considered to be the ‘power house’ of a cell and its dysfunction is associated with cell death. Improved mitochondrial function, which is also associated with weight loss, also may result in improved ‘egg quality’4.
Low energy diet and IVF birth rates
Another study looked at the impact of very low energy diet on IVF success rates5. Sim and colleagues conducted a study where over a 12 week period, women classified as ‘obese’ were divided into two groups – the experimental group who were subjected to (or benefited from) the full changes to diet and lifestyle that researchers wanted to test and the control group, those that did not experience all these changes. Being overseen by a dietitian, for six weeks the experimental group consumed a very low energy diet. This was then increased to a ‘normal’ intake over the next six weeks in the lead up to their IVF cycles. Additionally, the experimental group had the added experience of attending a weekly support group where they were provided with dietary, psychological and exercise advice. Plus they had the added benefit of being in a group and having the opportunity to connect with other women experiencing infertility and IVF, a process which cannot be underestimated. Those in the control group were simply advised to go see their GP for weight loss advice and provided the same printed literature as the experimental group.
It was found that those women in the experimental group not only lost more weight but also had higher pregnancy rates (48% versus 14%) and higher live birth rates (44% versus 14%) plus the added benefit of only needing to do two cycles to get there take home baby, as opposed to four cycles in the control group.
In this case, participating in a fully guided meal plan and getting the right emotional support certainly appeared to contribute significantly higher pregnancy and birth rates.
There is the concern, that in order to continue eating foods that are ‘keto’ some women may be inadvertently eating higher amounts of trans-fats – the bad one, for pretty much everything, including fertility. Transfats are found in a lot of prepared and prepackaged foods as well as some animal fats and in small amounts red meat. Speaking of the impact of eating red meat on IVF success rates, this was discussed in Eat Think Grow were it was reported that the consumption of red meat was associated with poorer embryo development and pregnancy rates6. Again in the quest to eat ‘keto’ it becomes a temptation to start eating more and more meat for the ease of it. I’m not saying eat more meat is necessary a bad thing for your keto diet (though some would) , but you need to be mindful of your other goals and what the evidence says there impact is on IVF success rates, not just being in ketosis.
Saying that, I would like to think by and large though, most people doing keto have enough ‘food literacy’ to know that you don’t eat prepackaged foods (cause a lot of the time they aren’t actually keto anyway) and to try and consume fats in healthier and alternative way than just having steaks 3 times a day.
To sum it up
As it stands, there is insufficient data to recommend the ketogenic diet to women doing IVF. The studies done primarily are only looking at women with PCOS and those that are labelled ‘obese’. Also, these studies are not all necessary looking only at the ‘keto diet’ as we know it. If you fall into the one of the categories of ‘obese’ or having PCOS and you have, say, six months to go before you do your IVF cycle and some significant weight loss to achieve than it would certainly be worth a go.
But the benefits you experience might be from weight loss as opposed to specifically the keto diet.
If you are three months or less before your IVF cycle, I would certainly be seeking professional advice before making such radical changes – although the data is far from water tight, in my opinion there is just enough doubt to think twice, or at least have a good discussion with your treating team and make sure that whatever changes you are making are optimized for your individual medical condition and cycle.
1. Mavropoulos, J., Yancy, W., Hepburn, J. & Westman, E. (2005). The effects of a low-carbohydrate, ketogenic diet on the polycystic ovary syndrome: A pilot study. Nutritional Metabolism 2: 35 doi: 10.1186/1743-7075-2-35
2. McGrice, M. & Porter, J. (2017). The Effect of Low Carbohydrate Diets on Fertility Hormones and Outcomes in Overweight and Obese Women: A Systematic Review. Nutrients 9(3), 204; https://doi.org/10.3390/nu9030204
3. Moran, L., Tsagareli, V., Norman, R. & Noakes, M. (2011). Diet and IVF Pilot Study: Short term weight loss improves pregnancy rates in overweight/ obese women undertaking IVF. Australian and New Zealand Journal of Obstetrics and Gynecology 51 455 – 459
4. Kulak, D. & Polotsky, A. (2013). Should the ketogenic diet be considered for enhancing fertility? Maturitas 74 p10 – 13
5. Sim, K., Dezarnaulds, G., Denyer, G., Skilton, M. and Caterson, I. (2014). Weight loss improves reproductive outcomes in obese women undergoing fertility treatment: a randomized controlled trial. Clinical Obesity 4 61 – 68
6. Braga, D., Halpern, G., Setti, A., Figueira, R., Iaconelli Jr, A. and Borges Jr, E. (2015). The impact of food intake and social habits on embryo quality and the likelihood of blastocyst formation. Reproductive BioMedicine Online 31 30–38.
*That’s a joke by the way… obviously I wouldn’t want to lose half my body weight in the first week, or at all!