A recent study presented at the Endocrine Society’s Annual Meeting in Atlanta showed that male runners who do not receive enough energy from their diet are at risk of developing stress fractures. Dr. Melanie Haines, M.D., General Hospital in Boston, Massachusetts stated that male runners including recreational runners should be counselled on the importance of adequate nutrition and calorie intake to optimize hormones body condition, bone health, and factors to prevent stress fractures. She noted that female athletes are at risk of developing low bone density and stress fractures when under-nourished, however, more clarity is needed if the same process occurs in the male athlete. 

The research included 15 male runners and 16 non-athletes for control between the age group of 16-30 years. The researchers assessed their bone density, body composition, and blood hormone levels in the study and found that the bone density of the Tibial Cortex or outer shell of the bone of the lower leg was lower in athletes than in control. They also found lower weight muscle mass and hormone levels associated with fat mass were linked to lower bone strength in the lower leg. Dr. Haines stated that undernutrition resulted in a negative impact on hormones and bones with insufficient calcium and Vitamin D levels in the body. She added that hormones are very important for bone health and strength. 

Abnormal hormone levels contribute to low bone density and increased fracture risk. The Endocrine Society consensus the risk factors associated with insufficient diet such as poor bone strength, low body weight, decreased calcium and Vitamin D levels, reduced testosterone levels, and eating disorders. 

(Source: https://www.hindustantimes.com/lifestyle/health/study-finds-energy-deficient-male-runners-may-be-at-higher-risk-for-fractures-101655111469926.html )