Summary
Why do you lose your appetite during a heatwave?
Hot weather naturally reduces your appetite because your body prioritises cooling itself instead of digesting large meals. Heat may also lower levels of ghrelin, the hormone that triggers hunger. Even if you're less hungry, eating small, nutrient-rich meals helps maintain energy and hydration.
What are the best foods to eat during a heatwave?
The best heatwave foods are hydrating and nutrient-dense. Top choices include watermelon, cucumber, leafy greens, bananas, and Greek yoghurt, which help replace fluids, replenish nutrients, and provide sustained energy without feeling heavy.
Should you skip meals during hot weather?
No. Skipping meals can cause low energy and blood sugar dips. Instead, eat smaller, protein-rich meals throughout the day to support energy levels and make digestion easier in the heat.
What should you avoid during a heatwave?
Avoid too much caffeine, alcohol, skipping meals, exercising during peak heat, and long daytime naps. These habits can increase dehydration, worsen fatigue, and disrupt sleep during hot weather.
The UK has witnessed unprecedented summer heatwaves, pushing maximum temperatures beyond all historical thresholds and setting new records close to 38°C in parts of England [1]. In this heat, many Brits notice a sudden drop in their appetite. While it feels unusual, this is a natural biological response. When the weather heats up, our bodies work hard to regulate internal temperature by slowing down energy-consuming processes like digestion. Furthermore, studies suggest warm weather may lower the production of ghrelin, the hunger hormone.
However, your body still needs essential nutrients, protein, and fibre. To maintain your energy levels and stay healthy, experts recommend eating smaller, more frequent portions rather than large meals.
Top 5 Foods to Eat During a Heatwave to stay cool, hydrated, and energised
- Watermelon: Consisting of about 90% water, it helps replenish lost fluids while providing vitamin C and lycopene, which helps to support skin health in the sun. Enjoy it on its own, blended into smoothies, or paired with feta in a summer salad.
- Cucumber: High in water content and rich in vitamin K to support bone health. Slice it into water for flavour, mix it into salads, or add it to sandwiches.
- Leafy Greens: Spinach, kale, rocket, and lettuce are packed with nutrients to sustain energy without feeling heavy. Ideal for light salads, wraps, and smoothies.
- Bananas: Rich in potassium - which is quickly depleted through sweat - and natural energy-boosting sugars. They make a great portable snack or frozen healthy ice cream alternative.
- Greek Yoghurt: Cooling, high in protein, and rich in calcium. It helps you feel full without weighing you down and serves as a great base for breakfasts or dips.
5 Common Heatwave Mistakes to Avoid
Poor sleep, brain fog, and low energy during hot weather are often exacerbated by everyday habits. Avoid these common pitfalls:
- Relying on Iced Coffees: Too much caffeine can worsen dehydration and ruin your sleep cycle. Alternate every coffee with a glass of water and avoid caffeine in the afternoon.
- Skipping Meals: Missing meals causes blood sugar dips, leading to fatigue and irritability. Opt for light, frequent, protein-rich options instead.
- Exercising During Peak Hours: Working out during the hottest part of the day places extreme strain on your body. Shift workouts to the early morning or late evening.
- Drinking Alcohol to Cool Down: Alcohol disrupts sleep quality and accelerates dehydration, leaving you groggy and exhausted the next day.
- Sleeping All Day: Long lie-ins or afternoon naps disrupt your natural circadian rhythm, making it harder to fall asleep at night. Keep naps to 20–30 minutes.
Top Tip for Extreme Heat
Struggling to sleep in extreme heat? To help you keep cool and drift off, try this: Slightly dampen a cotton bedsheet with cool water and lay it over yourself. Sweet dreams!
Expert Advice
For expert advice on supporting your nutritional needs during a heatwave, contact our team of Nutrition Advisors.
Frequently Asked Questions (FAQs)
Why does hot weather kill your appetite?
When it's warm, your body heats up quickly and slows down digestion and internal functions to regulate temperature. Warmer weather may also lower ghrelin (the hunger hormone) production, making you feel less hungry.
What should I eat when it's too hot to eat large meals?
Focus on light, nutrient-dense foods with high water content, such as watermelon, cucumbers, leafy greens, bananas, and Greek yoghurt, eaten in smaller portions more frequently throughout the day.
How can I stay energised during a heatwave without relying on caffeine?
Prioritise hydration with water and electrolyte-rich foods, maintain a consistent sleep routine, avoid skipping meals, and limit heavy, sugary foods or excess alcohol that drain your energy.
References:
1. Iacobucci, G. (2026). Heatwave: “Red” alert issued for only second time in England’s history, with dangerous combination of high temperatures and soaring humidity. BMJ, [online] 393, p.e100057. doi:10.1136/bmj-2026-100057. https://www.bmj.com/content/393/bmj-2026-100057#:~:text=Temperatures%20are%20forecast%20to%20reach,first%20being%20in%20July%202022.