So in my last blog, I wrote about how exercise affects our sleep. This time, I want to look at how our food choices impact on our sleep, and how if we’re sleep deprived it can feel almost impossible to eat healthily and lose weight (if that’s your goal).
I’m pretty sure, if you’re reading this, that you are (or have been) sleep deprived at some point. So it’s not big news when I tell you that when we’re tired, we automatically reach for unhealthy food choices. But what if I were to tell you that it’s not just because those sugary or fatty snacks are comforting that makes us want to reach for them?
I don’t know about you, but my favourite snacks were always crisps and chocolate. And maybe a smattering of cheese and biscuits if I felt really hungry. I couldn’t help it, it’s just what my body was craving, and who was I to deny my body what it ‘needed’?
But then I learnt that when our sleep is out of kilter, our hormones are too, including our hunger hormones. The two most important being ghrelin and leptin. Ghrelin is the one that tells us we’re hungry and leptin is the one that tells us we’ve eaten enough.
When we’ve had enough sleep, we have just the right amount of each of these in our system, so we eat until we are genuinely full, then stop. We’re also more likely to make better food choices BUT, when we’re tired, our ghrelin levels are high and our leptin levels are low, meaning we’re more likely to overeat.
Not only that, but our body craves high calorie, high fat and high sugar foods too to give us energy to power on through. A really interesting study into men’s food shopping habits when they’re tired can be found here if you wanted to read more!
Hungry? Blame it on our hormones
It’s not just our hunger hormones that have us reaching for sugary snacks either! Our stress hormone, cortisol (which is also the hormone that wakes us up) is higher when we don’t get enough sleep as at the right levels it helps balance our blood sugar levels as well as regulating our energy levels. It also impacts our fat stores, meaning that we’re more likely to turn the not so good foods into fat than if we were well rested.
Those fat stores tend to be around the mid-section (AKA a ‘spare tyre’) and are made up of visceral fat which is the fat that wraps around your abdominal organs (rather than the type of fat that lies just under the surface of our skin).
Of course, the time many of us are most tired, and therefore more likely to snack is in the evenings. Eating sugary snacks at this time can affect our sleep in itself (why not check out my previous blog here). But the fact we’re eating high fat or high sugar foods so close to bedtime means we don’t have the time to wear those calories off the same way we would if we had them earlier in the day.
So if you feel like munching in the evenings (or at any time really), it’s worth remembering if you’re physiologically hungry, go ahead and eat, but try to make it something light and healthy. If you’re psychologically hungry, step away from the fridge!
But it’s actually not just what we’re eating that makes a difference to our sleep. It’s the timings and frequency that we eat too. You’ve probably heard me talk about our body clock (or Circadian Rhythm), well the timings of when we eat affects it too. So trying to stick to regular meal times helps our body clock stay in sync, which directly impacts our sleep too.
Now, I’m not telling you not to have the occasional treat, that’s obviously entirely up to you. But, I’m a believer that knowledge is power. Now you know the link between food and sleep and how what you eat and when you eat it can impact your sleep and why you might make poorer food choices when you’re tired, you can start to address what’s potentially the real issue. Not your will-power, but your lack of sleep!