Ketogenic Diet & Fertility

The Ketogenic Diet has gained popularity the last few years - after originally being discovered to help with epilepsy, the keto diet has been crowned by the low carb community the official best and only diet you should be on for diabetes, weight loss, cognitive benefits etc etc.

Unfortunately, not eating carbs (our brains preferred fuel source) also makes us grumpy, takes away an entire food group that your microbiome depends on: FIBRE, and can reduce our ability as women to ovulate.

Spoiler alert! You need to ovulate to fall pregnant.

When we have a look at the research, there are a few really good systematic reviews (like this one done right here in Australia!) that compare lots of different studies done where a low carb diet was performed and resulted in some improvements in pregnancy outcomes. Nearly all of these studies were done on women with PCOS, now we know insulin resistance can be one of the root causes driving PCOS, so yes a low carb diet may be helpful for this community - but low carb is not necessarily ketogenic.. low carb is when less then 45% of your macronutrient energy comes from carbs, keto is usually 5-10% carbs, the rest fats and protein. This research also doesn’t help us to understand what a ketogenic diet does to a woman’s fertility who doesn’t have PCOS.

So for women who don’t have PCOS, we NEED carbs to ovulate. If you don’t eat enough carbs, you can lose your period and that has happened to many women who train for body building competitions or have a very low body fat %. Hypothalamic amenorrhoea is a condition where women lose their period and the first line of defence to combat it: eating more carbs.

Onto gut health: ketogenic diets can severely impact our gut microbiome diversity simply because you cannot consume a large variety of vegetables, whole grains or legumes: all of which contribute to a healthy microbiome and enhanced fertility. We know higher intakes of whole grains are related to higher pregnancy and birth rates and this is especially true for IVF treatments (which this study shows beautifully).

In ketogenic diets, it’s not commonly recommended where to get your fat from, which can result in people increasing their intake of saturated and trans fats - these are a big no no for fertility! I am a big advocate for getting enough fats in the diet for healthy hormones, these fat sources are poly or monounsaturated fats - from nuts, seeds, avocado, extra virgin olive oil and fish.

So what does this mean for ketogenic diets and fertility?

Frankly, it’s a no from me, but you probably already guessed that. There is no evidence whatsoever to suggest ketogenic diets improve fertility rates and even in the studies that found lowering carb intake had a positive effect on fertility in women with PCOS - they were still consuming more then 5-10% of their total energy from carbs, so not entirely ketogenic.

Fertility diet will differ slightly for people, but it’s mostly a Mediterranean style diet rich in whole foods; fruits, vegetables, whole grains and legumes and mono and polyunsaturated fats. Yes, you can keep your sourdough bread!

For an individualised look at your fertility; book in a consultation with Ellie here where you can see what will be best suited to you personally.

Cover Photo by David B Townsend on Unsplash