We use many senses when eating
Tasty food usually smells good, and eating with a blocked-up nose makes food seem bland. Appearance is important, too – colours can be a warning (blue foods just don’t seem right) or add to the appeal.
What looks good is also influenced by fashion. White bread was once a luxury but is now seen as cheap and less wholesome than brown. An unusual neurological case shows how colour affects appetite. A patient of the neurologist Oliver Sacks lost colour vision from a brain injury, remembering colour but seeing the world in black and white. Food seen in black and white became unappetising (imagine eating a black tomato), but he could manage to eat white rice, yoghurt, black olives and black coffee.
Older people’s taste and smell become less acute, and their appetite goes down. They may pile salt or sugar onto their food, which is unhealthy. Adding ingredients that evoke the savoury taste of umami may help them eat more, and a hospital diet that does just that has been under trial in the UK. Researchers found that adding the flavour enhancers MSG and IMP (to induce the umami taste) stimulated hunger when the food was first tasted and then enhanced feelings of being full.
Texture is also crucial in our food likes. Some people are extra sensitive to particular textures, usually soft ones, and find certain foods impossible to keep down. For most of us, crunchiness is compulsive. Who wants stale crisps?Lead image:
Illustration © Glen McBeth