New research has found that men who were obese during childhood tend to have shorter penises, even if they are no longer overweight as adults.
A new one carried out in Vietnam and published in Journal of Sexual Medicine suggests that men who were obese as children may have shorter penises as adults, even if they lose weight later in life.
Researchers at Hanoi Medical University examined 290 heterosexual men who visited the university hospital for reproductive health checks between June 2023 and July 2024. Participants underwent detailed physical measurements, including height, waist and hip circumference, and multiple penis dimensions, in a flaccid, stretched and erect state.
To assess childhood obesity, participants were asked to estimate their body mass index (BMI) at 10 years oldusing adjustable 3D models. This age was chosen because it normally precedes puberty, when testosterone, which is an essential hormone in penis growth, begins to increase significantly.
The results showed that 63% of participants had a normal BMI at age 10, while 31% were obese. On average, participants’ penises measured 8.9 centimeters long flaccid and 14.4 centimeters long when stretched. However, men who reported having been obese in childhood presented shorter lengths in both states, compared to those who had a healthy weight.
The study did not find a significant relationship between adult BMI and penis length, although a higher waist circumference correlated with a slightly shorter flaccid length, and larger hips were associated with a slightly greater length when stretched. Researchers noted that obesity in adulthood can affect the appearance of the penis due to the accumulation of fat in the pubic area, instead of its actual size, says .
“There is a need to early interventions to mitigate the long-term effects of childhood obesity on penile development”, considers lead author Professor Bac Hoai Nguyen.
Experts caution, however, that the sample was limited to men seeking reproductive health assessments and may not reflect the general population. However, the study adds to the growing evidence linking early obesity with long-lasting hormonal and developmental changes.