Puttingolive oil on the dinner table could help you stay slim – because the smell makes us feel full.
The discovery comes after scientists tracked volunteers who ate a 500g yoghurt every day for three months.
Some had added olive oil, while others included rapeseed oil, lard or butter.
Those who had olive oil ate fewer calories overall, and none put on weight. Blood tests showed they had higher levels of serotonin, a so-called satiety hormone that makes us feel full.
Scientists at Munich’s Technische Universitaet and the University of Vienna said this was due to an aroma compound not found in other fats and oils.
They were able to recreate the results by adding the aroma compounds – but not olive oil itself – to yoghurts.
The aroma extracts from olive oil can leave us feeling fuller, cutting our calorie intake by almost 200 a day, they said.
German and Austrian scientists made the discovery after testing the appetite-suppressing properties of four different fats – olive oil, lard, butter and rapeseed oil.
The team at the Technical University of Munich and at the University of Vienna asked volunteers to eat half a kilo of yoghurt enriched with one of the four fats daily alongside their normal diet.
After three months, it was discovered that adding olive oil had the biggest effect on satiety – the feeling of being full.
Study author Professor Peter Schieberle said those who ate the olive oil yoghurt were found to have higher levels of the hormone serotonin – which controls the feeling of fullness – in their blood.
He added: ‘Subjectively speaking, these participants also reported they found the olive oil yoghurt very filling.
‘During the study period, no member of this group recorded an increase in their body fat percentage or their weight.’
Researchers were puzzled by why olive oil was so effective despite having the same fatty acid levels as rapeseed oil.
So, they conducted another experiment and found that even the smell of it had a powerful effect on the appetite.
Volunteers given yoghurt with added olive oil aroma extracts consumed an average of 176 calories a day less than those who ate it without.
Professor Schieberle explained: ‘The aroma group adapted their eating habits – but the control group participants were obviously not able to do likewise.
‘We also found that in comparison to the other group, the control group had less of the satiety hormone serotonin in their blood.’
He also hailed the findings as paving the way for new healthy but satisfying weight-loss foods, adding: ‘Our findings show that aroma is capable of regulating satiety.
‘We hope that this work will pave the way for the development of more effective-reduced fat food products that are nonetheless filling.’