Do you find it hard to resist a late-night nosh before bedtime? It’s possible, just possible, that hormones that are fuelling your pesky cravings.
Yes, yes, I hear some of you immediately decry: blaming our body chemistry is just another flimsy excuse for lack of willpower. But actually, there is science to back it up.
Orchestra of hormones
Recent studies have found a complex orchestra of hormones bubbling away in all of us, responsible for driving hunger or sending signals of satiety (fullness) telling us enough is enough.
Generally, the science says, our appetite-stimulating hormones get stronger later in the day, while those that tell us we’re full up are strongest in the morning and weaken as the day goes on. Which might explain why many people find it easy to skip breakfast, even when they haven’t eaten much the night before. And why sticking to a diet always seems harder as day wears on. (We’re much more likely to cave to cravings at nightfall.)
Hardwired for night
According to a Harvard study, this is because our appetite-regulating hormones are intimately linked to circadian rhythms—our sleep/wake cycle. In short, our bodies are hard-wired to eat less in the morning and more in the evening. Some suggest this is an evolutionary throwback to our hunter-gatherer days, when we needed a reason to get up and hunt (or gather), rather than laze in our cave-beds and scoff our stash.
Understanding a teensy bit about these powerful appetite-controlling hormones is useful in helping tame them. So here’s some of the main ones…
First there’s ghrelin, which sounds like a Harry Potter character. Ghrelin is the main ‘tempting hormone’, which tells us ”Hey guys, it’s party time, let’s eat!” Ghrelin is never happier than when we’re sleep deprived, when it springs into action.
Then there are two hormones which do the opposite to ghrelin—suppress appetite— called peptide YY and leptin.
Unlike ghrelin, levels of peptide YY drop when we haven’t had enough sleep. And when we eat too much sugar, flour or processed food, leptin can’t do its job well. In other words, poor sleep and poor food choices both make us want to eat more. (No surprise there.)
There’s insulin too, which helps our body process sugar and greatly affects appetite. We all know how excess sugar sends insulin into ‘spike and crash’ mode.
Another key hormone is oestrogen, the ‘female sex hormone’ (produced by men too, by the way, but at lower levels). Oestrogen works on the same neural receptors that release serotonin, our feel-good hormone. So when we have enough oestrogen, our body produces serotonin which makes us feel pretty smug and satisfied. But when oestrogen levels are low, our serotonin level falls too, forcing us to switch on Come Dine With Me and trough chocolate like there's no tomorrow.
Add to this cocktail, one final one— the ‘stress hormone’ cortisol. When we’re stressed, cortisol levels rise, which makes us hungrier. This in turn raises our blood sugar and insulin, which puts us back on the spike and crash cycle.
So, enough science already. What does it all tell us? How can we actually rebalance those hormones and tame our raging appetite?
Here’s our top 7 tips:
- Don’t skip breakfast and eat regularly. Consuming a good part of our calories at breakfast has been shown to really help us stick to a diet plan.
- Include quality protein in every meal—plant-based sources such as nuts, seeds, beans, avocados, coconut, olive oil, tofu. (If we’re flexitarian, it’s going to be a lot easier.)
- Eliminate sugary drinks, both hot and cold—you really can do without them.
- De-stress throughout the day. Even a minute or two is better than not at all.
- Prioritise sleep to give your appetite-suppressing hormones a fighting chance.
- Try eating mindfully. (There’s loads of advice out there.)
- Set a night-time eating curfew. Brush your teeth, put up the ‘kitchen closed’ sign, lock the kitchen door and throw away the key, whatever.
Photo courtesy of Evieanna Santiago/ Unsplash