Can Your Diet Prevent Gestational Diabetes?

So the question then becomes… what are the modifiable risk factors of gestational diabetes, since we can’t change our age or go back in time and change our preconception weight and certainly can’t change our family history or ethnicity.

So we are breaking down the modifiable risk factors below that focus on what you can do before and during pregnancy.

Reducing The Risk of Gestational Diabetes Before You Get Pregnant

If you have any of the above risk factors, focusing on nutrition & lifestyle modifications in the preconception phase is important to reduce the risk of gestational diabetes.

Here’s what’s been shown to reduce GDM risk:

1. Follow a Mediterranean-style pattern of eating

The Mediterranean diet has been shown to support blood glucose control and reduce insulin resistance.

Here’s what to prioritise:

• Plenty of different coloured fruit & veg: Nutrient-dense and anti-inflammatory
• Extra virgin olive oil & other healthy fats (nuts, seeds, avocado): Beneficial for hormones (including insulin)
• Oily fish and seafood multiple times a week: Research shows this can help counteract insulin resistance
• Low GI carbohydrates: Don’t fear carbs! Choosing wholegrain and lower GI options can support a healthy pregnancy and better glycaemic control. Avoiding carbohydrates or following low carb diets does not prevent gestational diabetes and is not advised before or during pregnancy. Read more about this here.

Not sure where to begin with the Mediterranean-style diet? Our expert Australian fertility dietitians are here to guide you through it, step by step book a comprehensive online consultation in our virtual clinic.

2. Pre-conception Weight

According to research published in 2023, entering pregnancy at a higher body weight (BMI > 30) can triple your risk of developing gestational diabetes. The fat cells make it harder for the insulin secreted by your pancreas to reach your cells and let glucose in from the bloodstream.

Whilst crash dieting before pregnancy is never advised, if you have a desire to reduce your body weight work closely with a dietitian and exercise physiologist alongside your GP to detail a thorough and sustainable lifestyle plan that supports your goals, ideally 6-12 months prior to planned conception to support GDM risk reduction.

3. Improve Pre-existing Insulin Resistance with Diet, Exercise & Medications and/or Supplementation

If you need a little refresher on what insulin resistance means, check out our previous article on the topic here.

One of the most predictive factors of developing gestational diabetes, is having a history of higher than optimal blood glucose levels, the exact number has been debated by scientists. Some say anything more than 5.1 mmol/L increases the risk, whilst others are a little more generous and offer up 5.6 mmol/L or higher.

Of course, we can all have a once off funky blood glucose level thanks to a bad night’s sleep, running to the blood test centre right before, and even what we ate the day before. But a pattern of insulin resistance prior to gestational diabetes presents a critical opportunity to work on managing it well through diet, exercise, sleep and stress management as well as targeted supplementation, where appropriate, including Myo-Inositol, which has promising research regarding its ability to not only improve PCOS management but also gestational diabetes risk.

You can learn the detailed strategies for managing Insulin Resistance on our podcast, Fertility Friendly Food.

4. Prioritise Movement

Regular movement helps lower blood glucose levels and improves your body’s sensitivity to insulin, making it easier to keep blood glucose in a healthy range.

Just 30 minutes a day of walking, pilates or another activity that suits your preferences can help open up the gates for glucose to move into the muscle drawing it out of the blood stream, even a 10 minute walk after main meals can significantly improve post-meal blood glucose levels.

5. Focus on Sleep Quality

Poor sleep can interfere with insulin sensitivity, especially fewer than 4-6 hours per night. Aim for 7–9 hours of restful sleep each night.

6. Manage Stress Levels

Easier said than done, but chronic stress can drive blood glucose fluctuations via cortisol release. Try incorporating calming activities into your day such as stretching, breathwork, meditation, or a quiet walk outdoors or even sitting down to read your favourite book.

What Can You Do To Reduce Your Risk of Gestational Diabetes Once You’re Pregnant?

Even if you’re already pregnant, there are still some things you can do to reduce your risk. An important reminder is that ultimately, your placenta is going to spit out the hormones that interfere with the action of insulin during pregnancy. Sometimes you can do everything “right” when it comes to your lifestyle and you can still be diagnosed with gestational diabetes. This is not a personal failure; this is just sometimes the nature of pregnancy itself.

Similarly to the points above, it is important to:

• Aim to eat regularly with balanced meals and snacks, focusing on including foods from the Mediterranean diet and low GI carbohydrates.
• Stay active (as approved by your care team)
• Manage stress and prioritise sleep
• Attend regular check-ups and screenings
• Understand how much pregnancy weight you should be gaining based on your pre-conception weight and review this regularly with your care team.

If You’re Diagnosed With Gestational Diabetes, Don’t Panic

It’s not your fault.
Many people who are eating well, staying active, and doing “all the right things” still receive a diagnosis of gestational diabetes (GDM). And while it can feel overwhelming at first, there are effective ways to manage it, and you’re not alone.

Managing GDM effectively involves:

1. Monitoring your blood glucose levels (BGLs)

This helps you and your healthcare team understand how your body is responding to food, movement, and other factors that can influence BGLs.

2. Personalised diet and lifestyle support

Focusing on low GI carbohydrates and establishing a regular eating pattern can help keep blood sugar levels steady. Adding in regular movement can also make a big difference. Our fertility & pregnancy dietitians can support you with realistic, individualised strategies that fit your life.

3. Medication, if needed

Some people may need medication or insulin injections and that’s okay, again, this is not a personal failure. You should not be eating fewer and fewer carbohydrates in hopes of avoiding insulin injections. These treatments are safe during pregnancy and can help you and your baby stay healthy.

4. You can absolutely have a healthy pregnancy and baby with gestational diabetes.

With the right support, you can feel confident managing GDM and continuing to nourish both yourself and your growing baby. Whilst pregnancies impacted by gestational diabetes do increase the risk of certain complications such as larger babies, increased risk of pre-eclampsia, higher chance of induced labour or C-section and neonatal hypoglycaemia (or low blood sugar levels when baby is born).

A Team Approach for Gestational Diabetes Management

Managing gestational diabetes isn’t something that you navigate alone. A collaborative care team ensures you’re supported from every angle.

Your team may include:

• Dietitian: to create a personalised nutrition plan that supports stable blood glucose and overall wellbeing, ensuring you are meeting all key macro and micronutrients to manage gestational diabetes and support optimal development of your baby.
• Endocrinologist: Ongoing check-ins are important to keep an eye on your blood glucose levels and fine-tune your management plan as your pregnancy progresses, they typically also are in charge of managing your insulin doses.
• GP: for regular health monitoring such as blood pressure checks, measurements and referrals.
• Obstetrician or Midwife: to guide pregnancy care and track your baby’s development.
• Diabetes Educator: to help you learn how to monitor and interpret your blood glucose levels and how to administer insulin injections, if required.

At The Dietologist, we work closely with your healthcare team to ensure your plan is cohesive, evidence-based, and uniquely yours and helps support both you and your baby during your pregnancy, and beyond.

Continued support post-partum is critical for those who experience gestational diabetes, as there is a 7 times higher risk of developing type 2 diabetes later in life, so working on your postnatal nutrition and lifestyle is key to ensure you are entering parenthood happy and healthy for you and your family.

The Latest Gestational Diabetes Guidelines (2025)

The 2025 ADIPS guidelines bring an updated approach to GDM by raising the blood sugar levels used to diagnose slightly.

Gestational diabetes mellitus should be diagnosed using one or more of the following criteria during a 75 gram 2 hour oral glucose tolerance test (OGTT):

(i) FPG ≥ 5.3–6.9 mmol/L;
(ii) one‐hour plasma glucose (1hPG) ≥ 10.6 mmol/L;
(iii) 2hPG ≥ 9.0–11.0 mmol/L.

They also recommended earlier testing for high-risk individuals (between 10-14 weeks), and focusing more on care that’s respectful, personalised, and culturally safe.

Read the updated guidelines here.

Want A Personalised Preventative Gestational Diabetes Nutrition Plan?

Our expert Australian dietitians at The Dietologist can guide you with science-backed strategies tailored to your unique fertility story in our virtual clinic. Whether you’re planning for pregnancy, at risk of gestational diabetes, or navigating a recent GDM diagnosis, our expert team is here to support you every step of the way. Click here to get started today.