Many things have been touted as the explanation for why some people overeat and put on weight. A growing number of experts believe genetics hold they key, while others think it could be caused by anything from lack of sleep to being in love.
And now Portsmouth University scientists have a new theory to suggest. People who are overweight, they say, have a better sense of smell where food is concerned than those who are slim. And because they are more sensitive to food smells, it makes food more appetising. And that may play a part in why they overeat.
Writing in the journal Chemical Senses, the researchers explain how they tested volunteers' ability to detect odours. It turns out those with a high body mass index (BMI) had a far better sense of smell for food than those with a normal or lower BMI. When trying to detect other non-food smells, however, the overweight volunteers struggled.
So does gaining weight alter your sense of smell? According to the researchers it's most probably the other way around, with people who have a good nose for food being more susceptible to eating more. That's because the part of the brain that's involved with smell is also linked to the area that processes information about feeding.
The researchers also discovered that our sense of smell is heightened after we've eaten, rather than before. And that, they say, may also explain why overweight people keep eating, even when they're full.
Could new drugs developed to alter our sense of smell help fat people lose weight? Or do we just make far too many excuses for why some people overeat?