How to Prevent Gestational Diabetes in Pregnancy Using Nutrition
words by Natalia Kay

What is Gestational Diabetes?

Gestational Diabetes is a health condition where a pregnant woman has elevated blood sugar levels during pregnancy.  There are 2 ways that this is identified:

  1. Gestational diabetes has developed during the pregnancy, and no previous issues with blood sugar levels or a diabetes diagnosis were not identified prior to pregnancy, or
  2. Gestational diabetes was diagnosed during the pregnancy, meaning that most likely issues with blood sugar levels or a diabetes diagnosis were not identified prior to pregnancy.


Why does my blood sugar rise during pregnancy?

During pregnancy, most women will experience weight gain, which increases blood sugar levels in most people.  Hormones secreted from the placenta also create a rise in blood sugar levels.  Unless you have Type 1 Diabetes, the pancreas secretes insulin into the body to lower blood sugar levels.  For some people who continuously have high blood sugar levels, due to eating too much sugar, the body produces more and more insulin to reduce blood sugar.  This is where insulin resistance can occur.  This means that your body is becoming less responsive to insulin, and your blood sugar levels don’t reduce to normal levels.  This does affect all pregnant women.

A woman develops gestational diabetes when her blood sugar levels are no longer able to reduce to normal (or acceptable) levels.   Insulin resistance can also occur prior to a pregnancy, but if your GP hasn’t checked your blood glucose and insulin levels, this may not be detected.  This is why many people have undiagnosed type 2 diabetes.


What causes a rise in blood sugar levels?

Carbohydrates are the main reason why blood sugar levels rise in most people.

Carbohydrates are a macronutrient that the body needs for basic survival, along with proteins and fats.  Macronutrients are needed in large amounts by our body.  Our Vitamins and Minerals are micronutrients, meaning that we only need them in small amounts.

Protein forms the building block of muscles, blood and skin.  Protein is broken down into amino acids, hormones, enzymes, fluid balance, collagen, maintaining acid-base and many other functions.  Proteins do not increase blood sugar levels.

Fats (or lipids) are stored in the body as excess fat, energy production, help protect organs and create cholesterol.  There are many different types of fats such as phospholipids, triglycerides, sterols, essential fatty acids, saturated fats and unsaturated fats.  Fats do not increase blood sugar levels.

Carbohydrates are classed as simple carbohydrates (sugars) and complex carbohydrates (starches and fibres).  Foods that are simple carbohydrates are soft drinks, juices, baked treats and cakes, lollies, raw sugars, high-fructose corn syrup, and sugary breakfast cereals.  Complex carbohydrates are foods that are fruit, vegetables, nuts, beans, and whole grains.  Most carbohydrates get broken down to glucose which is used for energy.  What doesn’t get used by the body, gets stored as fat for later use.

Some foods can be a mixture of carbohydrates and protein, such as yogurt and dairy.


Risk factors for Gestational Diabetes

There are risk factors that make some women more susceptible to Gestational Diabetes.  The main ones are:

  • Previous history or family history of gestational diabetes, pre-diabetes or type 2 diabetes
  • Being overweight or obese prior to pregnancy
  • Being older, especially those over 40 years old
  • Non-Caucasian
  • Some medications
  • History of PCOS (polycystic ovarian syndrome)

It is important to note that some women also develop gestational diabetes even when they have no risk factors at all.

Many women who have been diagnosed with gestational diabetes have a greater risk of developing Type 2 Diabetes later in life.


Seriously, why are blood sugar levels so important?

During pregnancy, elevated blood sugar levels can cause issues during labour, and it can also affect your baby.  Some of the issues are:

  • Birth defects
  • Macrosomia, or large babies. i.e. baby’s birth weight of 10+ pounds
  • Injury to the baby due to its large size, such as becoming stuck in the birth canal. This is extremely serious and may require emergency treatment for both the baby and the mother.
  • The baby is born with hypoglycaemia, also known as low blood sugar. Remember that everything mum eats is passed onto the baby.  So if mum is having 3 cans of soft drink a day, so is Bub
  • Mum has an increased risk of pre-eclampsia, which is higher than normal blood pressure
  • Mum may require a c-section delivery, which can be devastating for some women wanting to have a natural birth
  • The baby is predisposed to obesity, diabetes and heart disease, due to a change in genes because of the elevated blood sugars


How do I get diagnosed?

In Australia, all pregnant women are regularly screened at their prenatal appointments.  They have urine and blood screening.  An Oral Glucose Tolerance Test (OGTT) is completed around the 24th week of gestation.  If you feel that something is “off” with your pregnancy, such as you have symptoms of excessive thirst, excessive urination, re-occurring thrush, and tiredness, then please see your GP or midwife or treatment hospital as soon as possible.


What can I eat and drink?

Once you have a diagnosis of Gestational Diabetes, you will need to monitor your blood glucose levels several times a day.  This is unavoidable.  You will be offered diet support usually from a dietitian or resources from the hospital or pre-natal clinic you are attending.  Many of these resources will still say it is safe for you to eat high carbohydrate foods, such as bread and pasta, but then you will require insulin medication to reduce your blood sugar levels.

Reducing the amount and type of carbohydrates is beneficial so that you can avoid needing to take insulin medication.

Foods and drinks that are safe:

  • good fats such as nuts, seeds, fish, plant fats, avocado
  • proteins such as meat, poultry, fish, seafood, eggs
  • dairy such as cheese, plain Greek yogurt, small amounts of butter
  • non-starchy vegetables, including asparagus, broccoli, celery, cucumber, mushrooms, radish, zucchini, lettuce, spinach, eggplant
  • water, coffee (no milk), black tea (no milk), some herbal teas, small amounts of almond or coconut milk, and sparkling water.

Some people utilize a Glycaemic Index phone app to identify which foods will raise blood sugar levels quickly.  The Glycaemic Index is a score of foods that increase blood sugar levels within a 2-hour time frame.  Foods are scored low, medium or high.


What can’t I eat and drink?

Foods that are highest in carbohydrates and which will raise your blood sugar, such as:

  • grains, whole grains and anything made with flour such as pasta, pizza, bread, pancakes, cookies, crackers, granola, cereals, waffles
  • legumes, such as beans and lentils
  • high starchy vegetables such as potatoes, sweet potatoes, peas, corn
  • fruits
  • milk and some yogurts
  • soft drinks, sports drinks, cordials
  • lollies, potato chips, takeaway fast foods such as hamburgers, hot chips, and most junk foods.

The body will always need some carbohydrates for survival, but it is important to know how much (grams) and to monitor serving sizes.  Pregnancy is a time of high growth period for the baby and high nutrient intake is also needed, so it is important to have your main meals plus a few small snacks.



Utilising the methods above and controlling your blood sugar levels with low carbohydrate foods, many women don’t need to introduce medications, such as insulin.  Unfortunately, there are some that still require medication, but they often can get through their pregnancy with a lower dose.


Nutrition, supplements and exercise

Pregnancy is a time when there is a high nutritional need for the mother, and everything the mother ingests is also passed on to the baby.  This includes soft drinks (sugar), alcohol (which can cause brain damage), and cigarettes (nicotine passes to the baby).  When mum ingests fresh food, good quality hormone-free and grass-fed meats, organic nuts and seeds, the baby gets all the nutrients needed to develop.  Sometimes this can be difficult for mums who have full-term morning sickness or who have food allergies or sensitivities.  A good quality practitioner grade prenatal vitamin can assist in filling the gaps.  Many women have low iron levels, low Vitamin D, poor gut health, and magnesium or calcium deficiencies.   Individual supplements are needed at this time.

Exercise is another way to reduce blood sugar levels, so gentle exercise such as walking, or yoga is highly recommended.



Most women will see a natural reduction in blood sugar levels after they give birth.  Unfortunately, the data is now showing that most women who have experienced Gestational Diabetes will go on to develop Type 2 Diabetes by the time their child turns 5.  Again, this is where blood glucose monitoring will be required and the recommendation of medication, if the diet is not improved.

Breastfeeding naturally helps to lower blood sugar levels.  This is due to the mammary glands using glucose (stored carbohydrate sugars) to create lactose, which is found in breast milk.  The longer you breastfeed, the better chance you have of reducing type 2 diabetes later in life.  Breastfeeding is also a high nutrient need, so the better you eat, the better your baby eats.

How much weight you have gained can also be a contributing factor to blood sugar levels.  For women who were already overweight and then gained 20+kg during pregnancy, it may be difficult to shift excess weight.  Focus on eating healthy and gentle exercise and slowly reduce your weight to a healthy range.

Further testing of blood sugar levels and insulin levels should be done following the birth of your baby.  See your GP to arrange this or it can be arranged by a Nutritionist.

If you plan on having more children in the future, please consider that you may also have issues with Gestational Diabetes in future pregnancies.


If you are concerned about gestational diabetes in your baby and looking for support promoting a healthy pregnancy we encourage you to reach out for a FREE Discovery Chat in our online clinic today.

Our wide selection of high-quality professional products is available as part of your free consultation and we express post products Australia-wide.


Click here for research sources

1) Nichols, L. (2015) Real food for gestational diabetes. USA. Pp 3-128.

2) Victoria State Government. (2021) Better Health Channel. Diabetes – Gestational. Retrieved from Diabetes - gestational - Better Health Channel

3) The Women's. (Undated). Gestational Diabetes. Retrieved from Gestational diabetes | The Royal Women's Hospital (

4) Whitney, E., Rolfes, S., Crowe, T., Cameron-Smith, D., Walsh, A. (2011). Understanding Nutrition. Cengage Learning Australia, South Melbourne. Pp 93-200.

Words by Natalia Kay

Words by Natalia Kay

Natalia is a qualified nutritionist and massage therapist, but she is also studying Reiki. She currently has 3 years of industry experience as a natural health professional and loves treating pregnancy (including gestational diabetes), fertility, skin, children's health and mood/mental health. Natalia is also mum to a teenage son Alex, and a beautiful cat named Moana. In her spare time, she loves beach days, moon-gazing, spiritual practices, tattoos, snowboarding, exercise and gardening.