If you’re managing gestational diabetes (GDM), you may have noticed that your fasting blood sugar levels can be high, despite eating well and following advice. This could be due to something called the dawn phenomenon. It’s a totally normal process, but it can interfere with your target blood sugar levels. The good news is that there are diet and lifestyle strategies that can make a difference.

What is the Dawn Phenomenon?

The dawn phenomenon is a natural rise in blood glucose that happens in the early morning hours, usually between 2 a.m. and 8 a.m. This happens in response to hormonal changes—specifically an increase in hormones like cortisol, growth hormone, and adrenaline—which help prepare your body to wake up and start the day.

These hormones cause the liver to release stored glucose into the bloodstream. In people without diabetes, insulin rises to counteract this. But during pregnancy, especially with gestational diabetes, the body’s ability to use insulin is already compromised due to placental hormones that make cells more insulin-resistant.

The result? A higher-than-expected fasting glucose level, even if you didn’t eat anything overnight.

Why Does It Matter in Gestational Diabetes?

High fasting blood sugar levels can be tricky to manage, but it’s important to keep them in check because it can be a contributing factor as to whether you need medication or insulin to manage your gestational diabetes.

Additionally, sustained high blood sugar levels may increase the risk of complications for both mother and baby.

What Can You Do? Diet Tips to Tackle the Dawn Phenomenon

Here are some diet-centered strategies that may help reduce the impact of the dawn phenomenon while keeping both you and baby nourished:

1. Rethink Your Evening Snack

A small, balanced bedtime snack can actually help keep fasting glucose in check. The goal is to prevent your liver from over-releasing glucose overnight. Try pairing:

• A slow-digesting carbohydrate (like whole grain crackers or a small apple)
• With a healthy fat or protein (like natural peanut butter, cheese, or Greek yogurt)

Example:
1 small slice of whole grain toast with almond butter

2. Watch Your Carbohydrate Portions During the Day

Aim for the following distribution of carbohydrate across the day (approximately 150g total per day):

• Breakfast: 15–20g
• Lunch: 40–50g
• Dinner: 40–50g
• Snacks: 15–20g

There are many carbohydrate counting apps and books available, such as Carbs and Cals, which can help you to work out the carbohydrate content of different foods. Alternatively, use food labelling on packages for the portion you’ve consumed.

If this sounds too intensive, simply aiming for around 1/4 of your plate as carbohydrate foods can really help.

Tip: Focus main meals around lean sources of protein, non-starchy veggies, high fibre carbohydrates and healthy fats like avocado, olive oil, nuts or seeds.

3. Avoid Sugary or High-Glycemic Foods in the Evening

Foods that spike your blood sugar quickly—like short grain white rice, juice, or desserts—can lead to a rollercoaster effect that makes fasting levels worse.

Swap ideas:

• Try lentils instead of white rice
• Choose new potatoes with the skin on instead of mashed potatoes or chips

4. Stay Consistent with Meal Timing

Eating dinner too late can interfere with your body’s overnight glucose handling. Aim to finish eating 2–3 hours before bed. If you’re hungry after that, choose a light, low-GI snack rather than a full meal.

Lifestyle Tips That Help Too

• Gentle evening movement: A short post-dinner walk can improve insulin sensitivity and help reduce overnight glucose rise.
• Good sleep hygiene: Poor sleep can increase cortisol levels and worsen fasting glucose.
• Track patterns: Keep a log of your evening meals and fasting numbers to spot what works for you. Everyone’s body responds a little differently.

When to Talk to Your Healthcare Team

If your fasting levels remain high despite making changes to your evening routine, don’t stress—sometimes medication or insulin is necessary and safe during pregnancy. Managing GDM is about doing your best and working closely with your healthcare team to keep you and baby healthy.

Final Thoughts

The dawn phenomenon can feel discouraging, but understanding why it happens is the first step to managing it. With smart diet strategies and a bit of trial and error, you can often reduce those early-morning spikes.

And remember, managing gestational diabetes is tough—you’re doing an amazing job!