In 2018 a study done at Stanford University in California set out to test the commonly accepted belief that, unless you have diabetes, your glucose levels should be of no concern. Second, and perhaps more controversially, they wanted to test a practice that has become a cultural norm: that cereal for breakfast is good for you.
Twenty participants were recruited, both men and women. None of them had been diagnosed with type 2 diabetes: their fasting glucose (as measured once a year by their doctor) was in the normal range. The experiment consisted of eating a bowl of cornflakes with milk while wearing a continuous glucose monitor
The results of this study were alarming. In those healthy individuals, a bowl of cereal sent their blood glucose levels into a zone of deregulation thought to be attainable only by people with diabetes.
Sixteen of the 20 participants experienced a blood glucose spike above 7.8mmol/L (the cut-off for prediabetes, signalling problems with glucose regulation), and some even spiked above 11.0mmol/L (in the range of type 2 diabetes).
That didn’t mean that the participants had diabetes — they didn’t. But it did mean that people without diabetes could spike as high as those with diabetes and suffer the harmful side effects those spikes cause. The discovery was groundbreaking.
The fact that a bowl of cereal causes spikes makes empirical sense. Cereal is made of either refined corn or refined wheat kernels, superheated, then rolled flat or puffed into various shapes. It’s pure starch, with no fibre left. And because starch is not the most palatable thing on its own, table sugar (sucrose, made of glucose and fructose) is added to the concoction. Vitamins and minerals join the mix, but the benefit of these doesn’t outweigh any of the harm of the other components.
Because of the way we eat today, early-morning spikes seem to be the norm. Whether it’s cereal, toast and jam, croissants, granola, pastries, sweet oats, biscuits, fruit juice, Pop-Tarts, fruit smoothies, acai bowls, or banana bread, the typical breakfast in Western countries is composed of mostly sugar and starch — a ton of glucose and fructose.
A breakfast that creates a big glucose spike will make us hungry again sooner. What’s more, that breakfast will deregulate our glucose levels for the rest of the day, so our lunch and dinner will also create big spikes. This is why a spiky breakfast is a one-way ticket to the glucose rollercoaster. A flat breakfast, on the other hand, will make our lunch and dinner steadier.
On top of that, first thing in the morning, when we are in our fasted state, our bodies are the most sensitive to glucose. Our sink (or stomach) is empty, so anything that lands in it will be digested extremely quickly. That’s why eating sugars and starches at breakfast often leads to the biggest spike of the day.
The best thing you can do to flatten your glucose curves is to eat a savoury breakfast.
An ideal breakfast for steady glucose levels contains a good amount of protein, fibre, fat and optional starch and fruit (ideally, eaten last). If you’re buying breakfast at a coffee shop, get avocado on toast, an egg muffin, or a ham and cheese sandwich, not a chocolate croissant or toast and jam.
Edited extract from Glucose Revolution by Jessie Inchauspé. Published by Penguin Random House Australia, RRP $34.99
Here Inchauspé shares two ideal breakfast options that will help flatten your glucose curves.
This is a really impressive dish to serve to your friends for Sunday brunch. It’s always met with ‘ooohs’ and ‘ahhhs’ when I set it down on the table.
1 medium leek, sliced 1 medium fennel bulb, roughly chopped
1 garlic clove
2 tbsp olive or avocado oil
100g baby spinach
10g dill, roughly chopped (reserve some for garnish)
2 tbsp tahini (see note below)
½ tsp chilli flakes
4 medium free-range eggs
Preheat the oven to 200°C/fan 180°C/gas mark 6. Heat the oil in a medium-sized non-stick ovenproof frying pan and saute the leek, fennel and garlic until softened and just starting to take on some colour — about 7 minutes. Add the spinach and allow it to wilt, then stir in the dill, tahini and chilli flakes with some seasoning. Make four holes in the mixture with a large spoon and crack in the eggs. Allow them to cook for a couple of minutes on the hob and then transfer the pan to the oven for 5-7 minutes, or until the eggs are just set. Garnish with some dill before serving. Tip: If the tahini you are using is not of a pouring consistency, simply mix with a few tablespoons of boiling hot water.
Broccolini with basil, lemon, chilli and parmesan
This makes a brilliant starter, main or side dish. It’s also perfect for breakfast, topped with a fried egg.
Serves 2 as a main or 4 as a starter/side
3½ tbsp avocado oil
Juice of 1 lemon and zest of ½
30g basil leaves, roughly torn
1 red chilli, deseeded and finely chopped
20g pine nuts, toasted
20g parmesan, grated
Bring a medium saucepan of salted water to the boil and cook the broccolini for 2 minutes. Meanwhile, in a large bowl, mix the avocado oil, lemon juice and zest, basil and chilli. Season well with salt and freshly ground black pepper. When the broccolini is ready, drain it and toss it in the dressing, ensuring that it gets a thorough coating. Scatter over the toasted pine nuts and grated parmesan before serving.