Childhood Obesity May Delay Onset of Male Puberty

Obesity in young boys can cause delays in mental and physical growth and development, which is quite the opposite of their female counterparts. These setbacks can lead to low self-esteem issues and make matters worse for severely overweight males, since obese children are often the subject of ridicule among their peers. According to a study recently published in the Archives of Pediatric and Adolescent Medicine, obese boys are 50 percent less likely to enter puberty by age 11½ than boys who are of normal weight. These findings directly contradict the outcome of previous studies involving young girls that have shown obese girls to be much more likely to enter puberty earlier than girls of normal weight.

The study was led by researchers at the University of Michigan Health System. Pediatric endocrinologist Joyce M. Lee, M.D., M.P.H., and colleagues, followed 401 boys born in 1991 who had diverse socioeconomic backgrounds and came from 10 different regions of the U.S. The height and weight of the boys were measured beginning at age 2 and continuing through age 12. Tanner genitalia staging was used to measure puberty. According to this scale, boys in stage one lacked genital development by the age of 11.5 years and were considered to have a late onset of puberty. Results of the analysis revealed that 14 percent of obese boys had a later onset of puberty, as did 13.3 percent of boys who were considered overweight. This was in comparison to just 7 percent of boys of normal weight who experienced a late onset of puberty.

According to Lee, “With the epidemic of childhood obesity, there’s concern this is going to have a negative effect on growth and development.” Regarding the study outcome, Lee said, “It confirms that obesity has effects on children’s growth and development for both genders.” However, Lee pointed out that although the study suggests that puberty works differently among boys and girls, it also reveals how little is known about the possible impact of obesity on boys, or what the impact will be if obesity trends continue. She noted that girls are already ahead of boys in regards to puberty, but could move even further ahead of boys in the same age group.

The exact cause for the development delay remains unknown. Although the hormone lepin was once believed to affect the early onset of puberty in girls, since elevated levels are found in both males and females who have more fat, it is a less likely explanation for changes in time of puberty onset. One possibility for boys is the theory that fat converts male hormones into estrogen, which slows male development.