Other vegetables have a very unique effect on our smell. The asparagus plant produces a compound called the asparagusic acid and, when it's digested by your body, it releases sulphur compounds too. It's these chemicals, such as methanethiol and dimethyl sulphide, that make your sweat and your pee smell a certain way. Sulphur compounds are very volatile, so they easily disperse in the air. That's why they're so easy to smell from the toilet bowl. This smell usually lasts more than five hours.

Not everybody produces this smell, although studies about this keep coming up with different findings. In the 1950s, research seemed to suggest that fewer than 50% of people produce the tell-tale asparagus pee odour, while in 2010, researchers found more than 90% of test participants did. So it’s not clear cut. And not everybody can perceive the stink: the ability to smell one's pungent asparagus-smelling pee seems to be down to genetics too.

However, when it comes to fruit and vegetables more widely, eating more of them can lead to a more attractive scent. A 2017 study in Australia found that men who had consumed more fruit and vegetables were significantly associated with smelling better – more fruity, floral and sweet. 

The study also notes, interestingly, when people have to rate people's faces, slightly yellower skin rich in carotenoid – a molecule from carrots, pumpkins, tomatoes and papayas and others – is also found to be more attractive. But the same study suggests that people consuming diets with a little bit of fat, meat, egg, and tofu intake were also associated with more pleasant-smelling sweat. Carb-heavy diets produced the least sexy of scents. 

Meat and fish can also produce a distinct body odour as animal proteins are broken down by the body into amino acids and fats, which are then excreted through sweat – where they interact with skin bacteria.