Is ketosis safe during pregnancy? | Nourish with Melanie #65

November 7, 2019 0 By William Morgan

The keto diet has been becoming increasingly
popular over the past few years, and personally,
I do use it with some of my clients who require
rapid weight loss.
But, is ketosis safe during pregnancy?
Today, I’m going to provide you with an update
on the research about low carbohydrate diets and pregnancy.
Stay tuned!
Rather than focusing on practical tips like
we do on many episodes of Nourish, today I
want to dig in to the research….
But, first I want to give you a quick overview
of what ketosis actually is….
Just like a phone, animal or plant, our body’s
need fuel to function.
We get that fuel from food….. more specifically,
usually from the carbohydrates in food.
But, I’m sure that you’ve heard that as long
as we still have water, we can survive for
a few weeks without food.
When this happens, our body uses our fat stores
for fuel in a process called ketosis.
‘Ketosis’ literally means making energy from
fat stores, and is a popular way to lose weight.
Now, current stats tell us that approximately
half of all pregnant women are overweight
when they conceive….and this additional
weight can lead to a range of pregnancy complications…so
it stands to reason that you might be wondering
whether a keto diet might be a healthy choice
during pregnancy, especially if you’ve been
diagnosed with gestational diabetes….
However, the current evidence suggests that
ketosis is generally not safe during pregnancy.
Let me explain…
First of all – pregnancy is a time when our
nutritional requirements soar!
And, when we cut out carbohydrate-containing
foods, such as fruit, dairy products, starchy
vegetables, legumes (like chick peas and lentils)
and wholegrains…it can be more challenging
to meet your pregnancy nutrition requirements.
Secondly, our fluid requirements sky-rocket
during pregnancy.
But, when our body is in ketosis, we lose
fluid faster.
You see, our liver and muscles store carbohydrates
to provide our body with fuel during short-term
fasts, like overnight.
And, each gram of carbohydrate-stores, which
are called glycogen, hang on to about 3 grams
of fluid.
So, if our body has used up all these carbohydrate
stores, it’s more difficult for our body to
retain fluid – which is why you need to pee
so much more often on a low carb diet.
Low fluid stores can increase your risk of
pregnancy complications such as constipation
and Urinary Tract Infections, which are already
a big problem during pregnancy.
Thirdly, although you may be tempted to go
on to a low carb diet if you develop gestational
diabetes, a study of lower carbohydrate diets
in women with gestational diabetes, found
that it didn’t improve the number of women
who needed to commence insulin injections.
Number four, and probably most importantly,
is that the ketone bodies which are produced
when our body is in ketosis, cross our placenta.
As our babies require a constant source of
carbohydrates for growth and development,
there are concerns about how these ketone
bodies, and the lack of carbohydrates may
impact the growth and development of your
However, it’s important to note that a ketogenic
diet can be one of the best treatments for
some women with epilepsy.
So, it’s important that more research is done
into this area.
In 2017, research was undertaken on two pregnant
women with epilepsy as they followed a ketogenic
diet throughout their pregnancies.
The first woman didn’t follow a true keto
diet, but had a reduced carbohydrate diet,
including approximately 75 grams of carbohydrate
per day from fourteen weeks gestation.
She experienced a range of nutritional deficiencies,
but had a healthy baby.
So, that’s great news!
The second mum was on a keto diet prior to
conceiving, and stayed on this diet throughout
her pregnancy.
She delivered a healthy baby, but unfortunately
the baby was born with physical deformities.
I should also mention that there have been
some animal studies conducted, and these have
also found mixed results.
Some of the side effects of ketosis during
pregnancy in these studies have included problems
with brain development, physical deformities,
nutritional deficiencies and behavioural issues
in the offspring.
Furthermore, preliminary research seems to
suggest that ketosis is not recommended in
the weeks leading up to conception either.
To summarise, I think that we need to remember
that there’s not much research on whether
or not ketosis is safe during pregnancy, and
until more evidence comes out on how to manage
it safely, it’s wise to cease your keto diet
prior to conceiving, or as soon as you know
that you’re pregnant, if at all possible.
If you have epilepsy, and really need to stay
on a keto diet, make sure that you see a dietitian
with expertise in this area.
Now, if you would like help with a healthy
diet during pregnancy, I’d love you to download
my free pregnancy meal plan.
Just go to,
and make sure you subscribe so that you receive
my weekly videos.
I look forward to seeing you again next week.