As the UK braces for another potential heatwave, with the Met Office warning temperatures could reach the 30s again within days, a doctor has explained why many people lose their appetite in hot weather. Last week's heatwave saw a record-breaking peak of 37.7°C in some areas, and now Dr Nighat Arif, a TikTok doctor with over 324,000 followers, has shed light on the body's response.
Why Your Brain Switches Off Hunger
In a viral video, Dr Arif explained: "You're not off your food in the heat. Your brain is literally switching hunger off." She said that during a heatwave, the brain enters "survival mode," redirecting blood from the gut to the skin to cool the body. "Your hypothalamus, that's your body's thermostat, is working overtime to keep you at around 37 Celsius," she said. "It starts redirecting blood away from your gut to your skin to cool you down. Simply put, your digestion gets de-prioritised and your body is going 'I've got better things to do'."
Hormonal Changes and Thirst Confusion
Dr Arif noted that hot weather can cause a drop in the hunger hormone ghrelin, while levels of GLP-1 and Peptide YY (PYY), which promote fullness, rise. Additionally, the brain can confuse hunger with thirst. "Suddenly water feels more urgent than food," she said. "In some people, thirst might not register straight away. Hence why in this heat you should regularly hydrate yourself, even if you're not feeling thirsty."
Impact on Energy and Digestion
These changes can lead to bloating, lethargy, and fatigue. "You could be left feeling bloated, not hungry, and honestly, you might be just feeling a bit off," she said. "It's part of your body's way of protecting you, and it's not failing you at all." She urged awareness of climate change's impact on the body.
Advice for Eating in the Heat
Dr Arif recommended eating smaller meals rich in water, such as yoghurt, fruit, and salad, and maintaining fibre intake for gut health. "If your appetite has disappeared in this heat, I want you to notice this today - are you actually not hungry, or are you just feeling overheated? If that's the case, time to cool down."
Weather Forecast
Although another heatwave is possible, the Met Office's Tony Wisson said it is unlikely to be as extreme as last week. "The forecast for this weekend suggests that temperatures could approach high-20s across parts of England, perhaps 30 degrees in parts of the southeast," he said. "Although a return to heatwave conditions is looking increasingly likely for some areas, the likelihood of such extreme high temperatures or high levels of humidity as last week is currently low." Current maps show 27°C forecast for southern England on Sunday, rising to 29°C on Monday and Tuesday.
