It's only natural

Every summer vacation, the endocrinology clinic at Shanghai Children's Hospital is filled with parents from across the country bringing their children for consultations about growth and height issues.

Zhou Shasha, an associate chief physician in the endocrinology department, said being overweight or obese are significant factors affecting adolescent height development.

Research indicates that in girls, being overweight or obese can impact sexual development and lead to an earlier onset of puberty. Generally, early puberty accelerates bone maturation and causes growth plates to close earlier, ultimately affecting adult height.

In the past, cases of early puberty in boys were relatively rare, Zhou said. "However, in recent years we have indeed observed more overweight and obese boys experiencing advanced bone age and earlier puberty," she said.

Most parents are eager for doctors to prescribe puberty suppression injections or growth hormone injections, which are relatively aggressive methods for promoting growth, even though only a small proportion of children truly require these treatments, Zhou said. The range of normal height for children and adolescents is quite broad, and largely determined by genetic factors.

"As long as a child has good nutrition and their growth potential is fully realized, there's no need for parents to compare or compete," she said.

In Shanghai, parental anxiety over children's height is high. Zhang Kexin, 38, became concerned when doctors said her 11-year-old son might enter puberty within a year, after they discovered he had an advanced bone age of 1.5 years.

However, her son's situation wasn't severe. The doctors predicted he could reach 170 cm, which they deemed a reasonable height.

Zhang was told growth hormone injections were an option, but was warned by the doctors it was "not something we recommend lightly".

Following the doctor's advice, Zhang took a natural approach to improving her son's height. She adjusted his academic schedule, reduced his workload, and set a firm bedtime of 9:30 pm, with all homework completed by 9 pm.

Dietary changes included 500 milliliters of milk and two eggs a day to ensure adequate protein, a vegetable-to-meat ratio of 60 percent to 40 percent, and three to four servings of steak each week. His physical activities ranged from swimming and basketball three times a week to 20 minutes of trampoline jumping or daily stretching exercises.

Over the past year, Zhang's family has strictly followed this routine and his height has increased to 164 cm. His advanced bone age was also reduced by more than half.

"Parents shouldn't rush to rely on tech and shortcuts to force growth spurts," Zhang said.

"Don't put too much faith in predicted heights, but use the difference between bone age and actual age as a reference. Slowing bone age growth scientifically can make a big difference, but the key is consistent execution," said Zhang.

Between 1985 and 2019, the average height of Chinese men increased by nearly 9 cm, the largest growth rate among 200 countries and regions, according to data published by The Lancet in 2020. The average height of Chinese women grew by 6 cm, ranking third globally.

"The rising height of Chinese children reflects more than just biological changes," said Yu, the sociology professor.

"It reveals how families increasingly prioritize nutrition, healthcare, and social status — with height becoming a symbol of a child's potential and a family's investment in their future."