Looking at someone who is overweight or obese can alter our sense of smell to make the scent of the world around us appear less pleasant , scientists have found . Researchers discovered viewing images of fat people caused participants in a study to rate odour samples as smelling worse - even though they were actually fragrance free . The scientists believe the effect may be caused by inbuilt negative bias that many people have towards those who are overweight and obese . Does looking at this image of an obese man on a bench conjure up a foul odour ? You may have an inbuilt prejudice if it does , according to a new study by scientists at the University of California , Los Angeles . Surprisingly they also found that those who had a higher BMI themselves tended to give the scent samples a lower rating . This suggests that people who have their own weight problems are perhaps also the harshest critics of others who are fat . Sit ups help tone your stomach , while squats strengthen your legs and bottom - but love handles are particularly difficult to shift . Now scientists believe they have discovered a way to ‘ melt ’ the excess white fat in muffin tops by turning it ‘ brown ’ . While white cells are responsible for muffin tops and flab in general , brown fat cells convert excess energy in food into heat . To make white cells behave like brown ones , researchers at the University of Bonn discovered a new signalling pathway . By experimenting on mice , Professor Alexander Pfeifer from the Institute of Pharmacology and Toxicology at the University Hospital Bonn discovered a new signalling pathway for a molecule called adenosine . Adenosine is known to activate brown fat cells , and is typically released during stress . The adenosine signal is transmitted by the adenosine receptor A2A . If adenosine binds to this receptor in brown fat cells , fat burning is significantly stimulated . The researchers transferred A2A receptors from brown fat cells to white fat cells in mice and found they started to burn more fat . Dr Ayako Tomiyama , an assistant professor of psychology at the University of California , Los Angeles , said : 'You wouldn ’ t think that not liking someone ’ s weight could then be seen in a totally different sensory modality . 'It makes us think how else is weight stigma affecting our lives that we don ’ t even know about ? 'This is the first step in proving that the consequences of weight stigma could be very widespread in ways that we don ’ t even know . ' The researchers conducted two studies by showing participants two sets of images of people who were either overweight or normal weight . As they viewed each image , participants were asked to smell a container of lotion tinted with different food colourings and rate the scent . Each container was actually fragrance free and contained the same lotion . The researchers , whose work is published in the International Journal of Obesity , found that when images of overweight or obese people were displayed on the screen , participants gave worse ratings to the scent samples . Images of average sized or thin people produced ratings deemed as more pleasant . Writing in the journal , the researchers , who are also presenting their results at this week 's American Psychosomatic Society , said : 'The results showed that the substances were perceived to smell worse when they were paired with images of heavy individuals than when they were paired with images of thin individuals . The researchers say that subconscious disgust at obesity may be manifesting itself in people 's sense of smell . 'The effect was most strongly manifested by participants with higher BMIs ' The researchers claim the results could be a subconscious signal of disgust . Previous research has shown that there is a connection between feelings of disgust and the perception of foul odours . It could also be associated with widespread assumptions that people who are overweight have problems with body odour . Stigma in society against fat people can be a barrier to them changing their lifestyle , according to scientists . Angela Incollingo Rodriguez said that while some people are overtly biased against people who are overweight , others may not be aware that they harbour negative feelings . She said that bias within society may actually be making weight problems for those who are obese worse . In the UK around 62 per cent of adults are now considered to be overweight or obese while in the US 35 per cent of adults are clinically obese . A previous study by the same team in 2014 showed that girls who were called 'fat ' by the age of 10 had a higher chance of being over weight by the time they turned 19 years old . Miss Rodriguez said : 'It undermines people ’ s motivation to diet and exercise . 'If anything , stigma is a barrier to these lifestyle changes that people commonly use to lose weight . 'By being aware of our deep-seated attitudes regarding weight , we can begin to change our behavior . '
Scientists at the University of California , Los Angeles conducted the study . They found that people who were exposed to more than one type of radiation had a higher risk for developing cancer and other health problems compared with those who did not receive any radiation.