Healthy weight comparison chart for teenagers

There is no nationwide, one-size-fits-all fixed healthy weight comparison table. Currently, the common judgment basis in the domestic clinical and public health fields is divided into two categories. The first is the BMI percentile screening table for age, gender, and height released by the Chinese Center for Disease Control and Prevention in 2020. The second is the dynamic growth curve combined with individual growth and development trajectories. The single fixed value comparison table circulated on the Internet has extremely low reference value, and blind application can easily mislead.

I have been working in the child health department for almost 8 years, and every week I meet more than a dozen parents who come for consultation with messy comparison charts. Last week, a mother came in with her daughter who had just entered fourth grade. She said that according to an online search, "the standard weight of a 10-year-old girl is 35 kilograms." Her baby weighed 40 kilograms, which is almost 10% overweight. She had been feeding her baby boiled vegetables every day for the past half month. As a result, the baby had been dizzy in class recently and could not concentrate at all. After taking a test, we found out that the child had grown 7 centimeters in the past six months and was already 152cm tall. The calculated BMI was only 17.3, which was at the 25th percentile for girls of the same age. It was completely normal. On the contrary, improper dieting almost affected the development rhythm of puberty.

Let me first list some reference ranges for common age groups. Just have a rough idea of ​​the numbers in your mind. Don’t get stuck: the normal BMI range for 7-year-old boys is 12.8~19.3, and for girls, it is 12.7~19.2.； 12-year-old boys are 15.1~22.5, girls are 14.8~22.7 ； For 16-year-old boys, it is 16.9~25.0, and for girls, it is 16.5~24.3. The BMI algorithm here is very simple. It is weight (kilograms) divided by height (meters) squared. Just don't get the units wrong.

Oh, by the way, someone must have asked, since there is an official range, why can't we just make a comparison table for everyone to use? This is actually something that has been controversial in academia. Experts in the field of public health support a unified BMI percentile standard. After all, when schools and communities conduct large-scale overweight and obesity screenings, they can't measure body fat and take bone age measurements for every child, right? The unified standard has high efficiency and low cost, and is suitable for general screening. However, most front-line pediatricians and sports medicine experts do not advocate that ordinary families should apply this standard. Think about it, the development rhythms of children from the north and the south are different. The muscle mass of children who practice football all year round and those who sit at home and answer questions every day can differ by several kilograms. There are also individual differences in early development and late development. It is easy to misjudge with a fixed value card.

Last month I met a 14-year-old boy who has been practicing basketball for three years. His BMI is 25.1, which is already overweight according to official standards. But his body fat rate is only 14%, which is all muscle. Can you say he is unhealthy? On the other hand, there are also children whose BMI is within the normal range but whose body fat rate exceeds 30%. They are classified as hidden obesity and need to adjust their diet. There is actually nothing wrong with these two views, they just have different applicable scenarios.

If you just want to do regular monitoring for your child at home, you don’t need to look for those fancy comparison tables. Just remember two small practical details: First, fix the time when weighing. Choose to go to the toilet on an empty stomach every Sunday morning and wear the same thin clothes. Otherwise, there will be a difference of two or three pounds after eating hot pot and on an empty stomach in the morning. It is purely to scare yourself.； Second, don’t compare with your neighbor’s kids, just compare with yourself. Look through your child’s physical examination book when he was a child. If his weight growth has been following his own curve, even if he is one or two pounds heavier than the “standard value” posted online, there is no need to panic. Unless the weight curve suddenly jumps up two percentile ranges, then you need to pay attention to whether he has eaten too much and moved too little recently.

Oh, by the way, I forgot to mention that the weight of adolescent children fluctuates greatly, especially for girls before and after their period. They may gain three or four pounds due to edema, which is normal. Don’t feel threatened when you see weight gain. To be honest, I have seen too many parents struggle with the number of one or two pounds, weighing their children at home every day, and opening their mouths to say "you are fat again". Adolescent children are inherently sensitive, and some even secretly induce vomiting, go on a diet, and develop eating disorders. That is much more serious than a few extra pounds of meat.

Seriously speaking, is there any absolute standard comparison table? A child who runs and jumps without panting, can meet the standards in physical education classes, sleeps well, has regular bowel movements, and has full energy is ten thousand times more important than the cold number on the table.