Sleeping Through a Heatwave

What to eat when the heat won’t let you sleep

With Gigi Erhardt, TGQ’s resident nutritionist

The Heat Is Working Against You and More Than You’d Think

Falling asleep depends on the body’s core temperature dropping by half a degree or so right as we settle down; it’s one of the signals that tells the brain it’s time to switch off. Heat gets in the way of that drop, which is part of why summer nights tend to feel lighter and more broken than restful ones in cooler months. Gigi’s first point when we spoke to her is that this isn’t a one-size-fits-all problem. Hormonal fluctuations change how the body handles heat. One reason a hot flush can feel uncannily like a heatwave arriving from the inside, complete with a racing heart and a small spike in blood pressure.

The Bloat Nobody Warned Us About

It’s easy to feel bloated in summer and quite ironically the months that we yearn for our bodies to behave themselves and show up in the best light. Gigi explains that in real heat, blood is diverted away from the gut towards our skin to help cool the body down. In doing so, the gut can trigger inflammation and slow digestion down to a crawl, leaving gases and fluids nowhere much to go. It’s tempting to blame bloating purely on salt or simply the heat, yet our bodies are also competing with the stress of heat that rises cortisol. Early research suggests this shifts gut bacteria more noticeably in women than in men.

GIGI’S FIXES FOR HEAT BLOAT

• Swapping sparkling and salty drinks for something gentler such as still water or ginger tea which trap gas and encourage fluid retention.
• Choose electrolytes with more potassium than sodium. Gigi’s own go-to is a potassium-forward blend from Seeking Health.
• Take a short walk in the shade after meals — 10 to 20 minutes in the cooler parts of the day helps digestion along without adding to the heat load.
• Dress for your gut, not just the weather — loose, breathable fabrics and good posture ease pressure on the abdomen.

Lean on probiotic foods — a daily serving or two of yoghurt, kefir or fermented vegetables helps steady gut bacteria that heat tends to disrupt.

Water Retention and That Extra Glass of Wine

Heat is dehydrating faster than most of us clock: Gigi points out the body can lose 2 to 3 per cent of its mass in fluid within a couple of hours at high temperatures. In response, it releases hormones that tell it to hold onto every drop of water and salt it can, which is why puffier fingers and a tighter waistband can turn up even when you feel like you’ve been drinking plenty. Oestrogen makes blood vessels more permeable, which can add to swelling, while progesterone encourages the body to hold onto sodium, so if you’re in the second half of your cycle, the effect can be more pronounced still.

That extra glass of rosé last night doesn’t help matters. Alcohol is dehydrating in its own right, so on top of everything heat is already doing, it asks the body to work harder still to hold onto fluid, while disrupting the deeper stages of sleep in the process. The fix isn’t necessarily cutting it out, so that’s a relief, but treating hydration as bookends to the drink rather than an afterthought is a favourable option.

Eating Your Way to a Calmer Gut

Gigi’s daytime advice is less about what to cut and more about pace and rhythm. Favour cooked, softened vegetables over raw where bloating is an issue, since raw veg is harder work for a gut already under pressure from the heat. Slow down at meals themselves: properly chewing food (she suggests around 20 chews a mouthful, eaten without rushing) does more for digestion than most of us give it credit for. And leave a proper four hours between meals where you can, to give the gut’s own overnight cleanup crew time to do its job between meals rather than being constantly interrupted. Alongside all this, aim for a solid 30g of protein at each meal (a large chicken breast is roughly there) to keep blood sugar and energy steady through the day.

The Art of a Sleep-Ready Dinner

Dinner timing matters more in a heatwave than most of us realise. Gigi recommends eating something light by around 6 to 7pm such as grilled fish or tofu with steamed vegetables and a slow-releasing carbohydrate like sweet potato or quinoa is her template.  Partly because it supports the body’s conversion of serotonin into melatonin ahead of bedtime, and partly because it stops digestion competing with sleep later in the night. The other half of the equation is resisting the after-dinner graze, however tempting it is to pick at something cool from the fridge at 9 pm.

The Wind-Down Ritual

The last hour before bed is where Gigi’s advice for an evening routine is best applied. Lowering your use of screens and bright lights  for an hour before bed will give your body time to signal a clear run at winding down.  About thirty minutes before lights out, she suggests 400mg of magnesium glycinate alongside 3g of glycine, both thought to support the nervous system’s shift into rest. Her more unconventional tip is mouth taping during wind-down breathing exercises to encourage the parasympathetic nervous system to take over. It’s not for everyone, and best avoided if you have any nasal congestion or breathing difficulties, but for those it suits, it’s a small, low-cost addition to an evening routine.