In the U.S., adolescent children are facing ever-increasing social pressures to develop muscular or toned bodies. This can lead to young people engaging in potentially dangerous muscle-building behaviors, including concerning amounts of exercise, steroid use, and overconsumption of nutritional products, such as protein, protein supplements, and creatine. Researchers from the University of Minnesota School of Public Health (SPH) and University of California, San Francisco (UCSF) recently studied patterns of muscle-building behaviors from adolescence into early adulthood and found large percentages of adolescents use protein products, with many going on to use steroids.

The research, co-authored by SPH Professor Dianne Neumark-Sztainer and UCSF Assistant Professor Jason Nagata, was published in the journal Preventive Medicine Reports. 

Currently, most muscle-building supplements, such as protein powders and pills, can be bought over-the-counter by minors with little or no regulation. Muscle-building supplements are not screened by the U.S. Food and Drug Administration for safety or effectiveness before they enter the market. Many muscle-building supplements are often mislabeled or tainted with harmful products, such as steroids. Steroid use can lead to heart disease, kidney problems, and liver damage, which makes it critical to understand how young people might be using them.

“Many young people, as well as their parents and coaches, are not aware of the dangers of using protein supplements for muscle enhancement,” said Neumark-Sztainer. “The findings from our research show that protein supplement use in adolescence was associated with future steroid use in young adulthood. The findings provide important evidence regarding the harms of using protein supplements in adolescence.”

Data for the research came from Neumark-Sztainer’s long-running Project EAT study, which tracks the health and well-being of cohorts of young people from adolescence into adulthood. Starting in 2010, the researchers surveyed 1,535 adolescents (12-18 years) regarding their weight status, dietary intake, weight control behaviors, physical activity, and related factors and followed them for eight years into young adulthood (18-25 years).

The researchers found:

• 55% of males and 33% of females reported using protein supplements, such as powders and shakes, during adolescence and adulthood.
• 6.7% of males and 5.4% of females reported using steroids during adolescence and adulthood. 
• Adolescent boys who used protein supplements were twice as likely to subsequently use steroids eight years later in young adulthood.
• Adolescent girls who used protein supplements were five times as likely to subsequently use steroids eight years later.

“The findings show that protein supplement use in adolescence was associated with future steroid use in young adulthood,” said Nagata, the lead author of the study. “Policymakers should be aware that adolescents using muscle-building supplements are more likely to use illegal and harmful products, such as steroids, in the future.”

The researchers support the creation of bills that restrict minors from purchasing over-the-counter muscle-building supplements, such as those being considered in New York and Massachusetts.

Additionally, the study team recommends that pediatricians, coaches, and parents talk to adolescents about the use of muscle-building products and their potential dangers. In particular, they should know that people who use muscle-building supplements may have a higher risk for developing an eating disorder or muscle dysmorphia, a condition characterized by a preoccupation with not being muscular enough. Warning signs of these conditions include a preoccupation with food, supplements, appearance, size, weight, or exercise in a way that degrades the person’s quality of life.