A study from the University of Toronto suggests growing numbers of young people are becoming obsessed with the size of their muscles. This obsession is a mental health condition called muscle dysmorphia, also known as "bigorexia". Kara Becker, a certified eating disorder therapist, spoke to the HuffPost website about the affliction. She said: "Bigorexia is a psychological condition…which involves a distorted self-image that focuses specifically on muscle size and physical appearance." Sufferers can experience extreme distress over their perceived lack of muscularity. Bigorexia can afflict even those who work out regularly and have the physique of a bodybuilder.

Researchers said muscle dysmorphia was rising in teenagers and people in their twenties. The study stated that up to a quarter of men and 10 per cent of women in their research could suffer from bigorexia. Ms Becker said a variety of factors can cause young people to worry about their body shape. She said: "People with low self-esteem, perfectionism, or obsessive-compulsive tendencies are more vulnerable to developing this disorder." Social media may be a factor in exacerbating the problem. Youngsters can be overwhelmed with images of people with the "perfect" body. Another cause may be the aggressive marketing of muscle-building supplements and anabolic steroids.