Exercise addiction is nearly four times more common among people with an eating disorder, researchers have found.
Exercise addiction was defined as having an obsessive approach to fitness that could have a negative impact on someone's health and social life.
"It is known that those with eating disorders are more likely to display addictive personality and obsessive-compulsive behaviours," said study lead author Mike Trott of Anglia Ruskin University in the UK.
"We are also aware that having an unhealthy relationship with food often means an increased amount of exercising, but this is the first time that a risk factor has been calculated," Trott added.
The study, published in Eating and Weight Disorders, drew on data from nine studies covering a total of 2,140 people with a mean age of 25.
The researchers found that people displaying characteristics of an eating disorder are 3.7 times more likely to suffer from addiction to exercise than people displaying no indication of an eating disorder.
"It is not uncommon to want to improve our lifestyles by eating healthier and doing more exercise, particularly at the start of the year. However, it is important to moderate this behaviour and not fall victim to 'crash diets' or anything that eliminates certain foods entirely, as these can easily lead to eating disorders," Trott said.
According to the researchers, the study shows that displaying signs of an eating disorder significantly increases the chance of an unhealthy relationship with exercise, and this can have negative consequences, including mental health issues and injury.
"Health professionals working with people with eating disorders should consider monitoring exercise levels as a priority, as this group have been shown to suffer from serious medical conditions as a result of excessive exercise, such as fractures, increased rates of cardiovascular disease in younger patients, and increased overall mortality," Trott concluded.