How Your Blood Glucose May Affect the Way You Treat Others

Expert Insights & Quotes

I remember being surprised when I read John Gray's books on relationships and came across his idea that when a woman is hungry, she might suddenly remember something her partner did years ago and start complaining about it.

Here's what he wrote in his book Venus on Fire, Mars on Ice: Hormonal Balance - The Key to Life, Love, and Energy.

So, for the man seeking to have a nice day with the woman in his life, it's important to know that she can be feeling fine one minute and be thinking about food the next. Pay attention to the clues of depleted blood sugar. Your well-being depends on it! If she's hungry and stressed, you may easily find yourself in the proverbial doghouse for something you did hours, days or years ago. Nothing you can say will help. Take it from the man who's learned from experience: Just feed her fast, or she may experience selective amnesia and forget every good thing you've ever done in your life. Don't argue; it's like pouring gasoline on a fire. Just listen, nod, and... find her a restaurant!

At first, it sounded a bit sarcastic to me, as if women couldn't even take care of their basic needs and needed a man to step in. But this wasn't just a random idea - it came from what John Gray had observed while working with couples over many years.

Blood Glucose and Stress

What's the reason according to John Gray?

Each time we eat a snack or meal made from processed foods, our body reacts with fluctuations in blood sugar which in turn raise cortisol levels. The effect is as if we're being chased by a bear all day long, every day. Our bodies are designed to handle stress very effectively, but not hour after hour, day after day.

Everyday blood sugar fluctuations can leave us chronically stressed. And it's so difficult to be loving and supportive when you're feeling anxious and worried.

Blood Glucose and the Brain

Years later, I came across the same idea in Glucose Revolution by Jessie Inchauspé, a scientist who writes about food, diet and blood sugar. Who would have thought that a book about unhealthy glucose spikes could teach you something about relationships?

What John Gray observed in couples over the years, Jessie Inchauspé confirmed through research and continuous glucose monitoring.

Here are a few quotes from Glucose Revolution that I find particularly interesting:

This one is especially important because we tend to think of the brain as purely a mental organ, without paying enough attention to how it responds to physical factors such as diet and blood glucose levels.

Your brain doesn't have sensory nerves, so when something is wrong, it can't alert you with pain as other organs do. Instead you feel mental disturbances - such as poor mood.

What you eat feeds your microbiome, which communicates with your nervous system and can ultimately influence how you feel.

What's more, we're discovering that gut health is linked to mental health - unhealthy microbiomes can contribute to mood disorders. The gut and the brain are connected by 500 million neurons (that's a lot, but the brain contains a whopping 100 billion). Information is sent back and forth between them all the time, which could be why what we eat, and whether or not we have glucose spikes, affects how we feel.

High-Carb Breakfast and Negativity

This one really shocked me because it suggests that a high-carb or highly processed breakfast could actually affect the way you interact with other people - to the point where you start focusing much more on their negative qualities.

Thousands of scientific studies show how glucose spikes harm our body, but as I mentioned in the previous hack, evidence of the connection between glucose and the mind is still emerging. I've already described the research proving that the more glucose spikes in our diet, the more we feel symptoms of depression and anxiety. But thanks to a fascinating recent experiment, we also know that when we eat a breakfast that causes glucose spikes, we're more likely to want to punish those around us - we become vindictive and less agreeable to our peers.

Flatter curves can lead to our being more patient with our kids, more loving with our partner and more supportive to our colleagues.

The Bottom Line

I can imagine many experts criticising Glucose Revolution by pointing out that glucose spikes are a natural response to eating carbohydrates and that, as long as insulin brings blood glucose back down, there's nothing to worry about.

But do they take the long-term consequences into account? As John Gray wrote, we're not meant to feel stressed after every meal, day after day. Sooner or later, being on this constant rollercoaster is going to take its toll on us.

So if you've been less loving and supportive lately, snapping at people you care about, perhaps you don't need therapy - perhaps you just need to take a look at what's on your plate.