Would you eat spaghetti for breakfast? Let me ask you that again at the end of this blog …

I know my Uncle - Victor Hugo Gradisar - would.

As a kid, he use to cry out to my Nonna and Nonno for some pasta.

When he was a dad, he use to compete against his own kids for the leftover pasta the next morning. Whoever got up first, got to start their day with a bowlful of Spag Bog (aka, terrible Aussie slang for Spaghetti Bolognaise).

And who can blame him?

If I was on Death Row and was asked what I wanted for my last meal - it would be a bowl of my Nonna’s pasta (I might even make an exception to the giblets and tripe).

How Pasta Can Chop Up Our Sleep

Pasta is packed with carbohydrates - a source of energy to propel us humans through our day.

But carbs have got a bad wrap (mind the pun) lately.

That’s because when you eat a sh!tload of carbs - but don’t use their energy - the energy is stored as fat cells. Which in some ways is OK, as long as you burn the energy from those fat cells, rather than adding more fat cells.

Usually these fat cells are stored in places not of your choosing (eg, that spare tyre around the middle of your body).

And when you go to sleep and lay on your back, that spare tyre around your middle can push into your body. Snoring and often times apneas (cessation of breathing) ensue.

If you’re not breathing whilst your asleep, your brain goes “WTF?!” and mildly wakes you up. But our brains ain’t so good at remembering this fracturing of our sleep overnight. So we blissfully go through our day thinking ‘Why am I so tired?’

Thus over the long-term, eating excessive carbs can lead to poor quality sleep.

But What About The Short-Term?

This week I opened up the sleep newsletter from Mollie McGlockin and saw a very interesting study about the links between carbs and sleep (Vlahoyiannis et al., 2021).

Before Mollie’s newsletter hit my Inbox, I was having a conversation with my new mate and colleague, Emelie Wirbing from Sleep Cycle - where Em was saying that late-night carbs affect your sleep. Before Em could finish her sentence, she noticed I was shaking my head in the negatory.

“Nope. With the exception of caffeine and alcohol, any food that you put in your mouth doesn’t affect your sleep that night. I’ve looked at this recently.”

So it was good to see a new study on this topic.

This study happened to be a meta-analysis (ie, a study analysing data from as many good studies as it can find).

I was interested to see whether carbs affected SOL (ie, sleep onset latency, ie, the time taken to fall asleep). If so, this might mean people are more alert than usual after a big carb meal - or - they’re distracted from falling asleep because their guts hurt.

I was also interested to see whether carbs affected WASO (ie, wake after sleep onset, ie, being awake a lot during the night).

So I downloaded the study, and happily found a Table (ie, a grid with a bunch of numbers) and Forrest Plot (ie, a graph with a bunch of horizontal lines that might cross a vertical line).

Here’s the Forest Plot …

If you see a horizontal line that crosses the vertical line, it means that these two things are not related. For example, you can see that for SOL, the associated horizontal lines cross the vertical line on the left-hand side graph - and almost does for the graph on the right.

Strangely, the table that contains the data for the analyses for SOL are negatory (unlike the graph on the right). And they’re clearly negatory. Maybe someone’s ink ran out and they couldn’t keep drawing the line?

Anyways, their data means carbs don’t affect how long it takes you to fall asleep.

The same can be said for carbs making you wake up during the night. Nope. Those two things are not connected.

Spaghetti For Breakfast?

I noticed this meta-analysis did not include one of my favourite studies on this topic - probably because the researchers did not analyse the effect on the circadian rhythm.

But back in 2002, some terrific Swiss researchers compared having a carbohydrate-rich meal in the evening vs the morning (Kräuchi et al., 2002).

Compared to eating a bowlful of spaghetti at 9:30 PM, eating the same bowlful of spaghetti at 8:30 AM was more powerful at changing the timing of the circadian rhythm.

We have many ‘expressions’ of the circadian rhythm - meaning different ways we can measure it.

And so, it was the participants’ internal body temperature rhythm that moved 1 hr earlier after spaghetti in the morning, yet a 45-min circadian phase advance in heart rate (ie, their circadian rhythm of heart rate shifted 45-min earlier).

Their melatonin rhythm only shifted earlier by 15 min.

Conclusions?

My Nonna knew a few things about sleep without reading a single scientific study.

Sure she got the whole Chamomile thing wrong (leach & Page, 2015), but she knew a bowlful of her gorgeous pasta ….. sorry … I’m salivating …. (swallow) … there we go … wasn’t going to affect out sleep.

She also ensured as kids sleeping over her place, that we would sleep well.

She’d tuck us in with the sheet so god damn tight, it felt like a whole-body-straight-jacket. Your feet had no choice but to point out sideways.

Her Nonna-Sleep-Therapy worked!

Interestingly, she never made us pasta in the morning. But then again, she’s a classic night owl. No way was she going to get up early and make us a bowl of that deliciously mouth-watering …..

Excuse me for a moment. Gotta clean up all this saliva off my keyboard …

• Prof MG

p.s. Would you eat a bowlful of spaghetti for breakfast?