All of our metabolic processes generate heat, including digestion. For every 1,000 calories you eat, only 250 are converted into useful energy – the rest ends up as waste heat.
In hot weather, your body is already working hard to keep you from overheating, and it doesn’t need the extra heat from digesting a big dinner. So your appetite is temporarily dialled back and your body gets more of its energy from stored fat reserves instead.
- Why do I always get an energy crash in the afternoon?
- Why do I feel sick when I’m hungry?
- Why does 37°C feel so hot when our bodies are at that temperature already?
- Why do I always come up with my best ideas when I’m trying to get to sleep?