High performance sport has turned to nutrition in recent years to find new ways to improve performance, with fasting and extreme diets increasingly common.
This has prompted scientists from the University of Bern, in Switzerland to call for measures to protect athletes.
The researchers conducted a study to analyse the evolution of body mass index (BMI) in professional cycling. They found that between 1992 and 2022, the average BMI of the top five riders in the overall classification of a grand tour decreased.
"It is time for cycling's governing bodies to consider taking proactive measures to protect riders," the study concluded.
The researchers found that the average BMI of the top five riders in the three major cycling tours (France, Italy and Spain) dropped from 22.12 to 20.13 over ten years.
"In itself, a BMI of 20.13 is not bad for health and does not indicate future health problems. However, we point out that the downward trend in the BMI of the top five finishers of the grand tours is worrying," they said.
According to the study, the pressure to perform can lead to unhealthy behaviour, with possible negative consequences for riders' health in the short and long term.
Riders Geraint Thomas and Rohan Dennis have spoken in interviews about the eating disorders they experienced while trying to lose weight.
Cycling is not the only sport where weight gain plays a big role. Formula 1, ski jumping and rowing have all taken steps to curb the weight loss trend.
The University of Bern study suggests that the cycling's governing bodies could learn from this and take additional measures such as "broader education campaigns, as well as more proactive interventions, such as screening programmes or weight-based rules."
