As temperatures across the United Kingdom push past 30°C this week, many of us are reaching for the fridge more often and stepping away from the stove. The discomfort of cooking in sweltering conditions, coupled with a natural dip in appetite, has left plenty wondering whether our eating habits should change when the mercury rises. We spoke to nutrition experts to break down what the science actually says about food, drink, and staying well when summer throws its weight around.
Rethinking Protein When It’s Hot
There is no medical need to increase your protein intake during a heatwave, says Aisling Daly, senior lecturer in nutrition at Oxford Brookes University. Yet the practical challenge remains: many of our favourite protein sources — meat, chicken, and fish — require cooking, and standing over a hot stove or even managing a barbecue can feel unbearable when the air itself is already thick with warmth.
One kitchen tool worth reaching for is the humble air fryer. According to Radio 4’s Sliced Bread, cooking a chicken leg in an air fryer uses less than half the energy of a conventional oven. Because these devices are compact and quick, they also release significantly less heat into your kitchen, making them a genuine summer ally.
Don’t overlook the slow cooker either, despite it being a less fashionable fixture at the back of your cupboard. Although it operates for longer periods, it tends to be more energy efficient and generates even less heat than an air fryer.
That said, the most important thing to understand is that digesting protein naturally raises your body temperature. The stomach, intestines, and liver all expend considerable energy breaking down these complex molecules, which is why a juicy steak — however tempting — may leave you feeling hotter rather than cooler.
The good news is that protein does not have to come from a hot meal. Lentils, nuts, milk, tofu, and cheese all deliver protein without requiring intense cooking. Dr Daly suggests focusing on bean salads, eggs, pre-cooked meats, and plenty of Greek yoghurt — frozen, if you like. Blending fruit, vegetables, and yoghurt into a smoothie with a spoonful of peanut butter can also create a balanced, nourishing meal that requires no oven time at all. Lighter fish such as tuna, salmon, or prawns are another excellent option for warm days.
Hydration Means Eating Your Water Too
When we sweat, we lose water, and if we do not replace it, dehydration sets in. The NHS typically recommends six to eight glasses of fluid per day, but during a heatwave that figure can climb considerably. “There is no single amount that suits everyone, because how much fluid your body needs depends on lots of factors like your age, body size, activity levels, and health status,” says Dr Charlotte Mills, food and nutrition scientist at the University of Reading.
Athletes, pregnant women, and those who are breastfeeding are among those who need to drink even more frequently. However, staying hydrated is not simply about topping up your water bottle every couple of hours. “We need to eat our water as well as drink it,” explains Dr Daly, noting that 80 to 90 per cent of fruit and vegetables are composed almost entirely of water.
Cucumber, tomatoes, lettuce, celery, watermelon, and strawberries all contain water content above 90 per cent. Apples, carrots, cooked broccoli, and pears sit comfortably between 80 and 89 per cent, as do oranges, grapes, and pineapple. By contrast, boiled eggs are around 75 per cent water, while digestive biscuits manage just 2.8 per cent. Even a cheese and tomato pizza contains only 38 per cent water, and takeaway chips hover at roughly 51 per cent.
A simple but effective way to check your hydration levels is to examine the colour of your urine. Pale yellow indicates your body is well hydrated. If it shifts toward orange or dark brown, your kidneys are holding onto water because the body is not receiving enough — a clear sign you need to drink more.
Hot Drinks Can Actually Help You Cool Down
For those who cannot imagine abandoning their daily cuppa — even when the weather is sweltering — there is good news: warm or room-temperature drinks are just as effective at cooling you down as cold ones, according to Dr Daly. Research indicates that your body tends to sweat more quickly after consuming a hot drink, helping to release excess heat faster. After a cold drink, sweating happens more slowly. Your body works hard to maintain a core temperature of roughly 37 degrees Celsius, and it will use whatever method it deems most efficient.
The essential factor is staying hydrated, regardless of whether your drink is hot or cold. There is also no reason to give up your morning coffee, though excessive caffeine can increase urine production and contribute to dehydration. Matcha contains more caffeine than a standard cup of tea but less than a regular coffee. Dr Daly notes that one or two cups of coffee a day should have little impact on your hydration, but five or six will begin to make a difference. Alcohol, too, is a known dehydrant and should be consumed with extra caution in high temperatures.
You might also consider adopting a southern European approach to your daily routine: enjoy an early breakfast, take an afternoon siesta during the hottest hours, and savour a late dinner when the day begins to cool. It is a rhythm well suited to the body and the season.
Why it Matters
Heatwaves are not merely an inconvenience — they pose a real and measurable risk to public health, particularly for the very young, the elderly, and those with pre-existing medical conditions. Understanding how to eat and drink wisely during extreme heat is not about fussy lifestyle advice; it is a practical, evidence-based strategy for protecting the body when it is under the most strain. With temperatures in the UK increasingly pushing past comfortable thresholds, the small decisions we make about what we eat and drink could make a significant difference to how well we cope — and that is worth paying attention to.
