Although fluctuations in weight often occur as part of teens’ normal growth patterns, a drastic loss or gain in weight can potentially indicate something more serious. Sudden weight changes might happen as a routine part of a growth spurt or they might be red flags for emotional disorders or eating disorders. Discuss any concerns relating to your teen’s growth with his doctor, who can help you discover the cause of his rapid weight loss or gain.
Teens undergo rapid periods of growth around puberty that can last several years. During these growth spurts, the KidsHealth website suggests that many teens gain weight more rapidly as their body composition -- the amount of muscle, fat and bone in their bodies -- changes and develops. As long as the growth is proportional, KidsHealth provides reassurance that the extra weight is normal and healthy. Since not all teens grow in a similar fashion, the growth spurts can have the opposite effect on some teens -- causing them to lose weight if they do not eat enough to keep up with their bodies’ energy needs.
These growth spurts will not harm your teen or his overall health, but do mention them to your child’s doctor so he can make sure the weight changes are part of your teen’s normal growth pattern and not due to any underlying health or emotional issues. The doctor can also offer dietary suggestions that can help your growing teen get the nutrients she needs during these periods of rapid growth. Since many teens start to experience body image and self-esteem issues, the doctor can reassure her on the “normalcy” of her weight gain or loss.
An extreme shift in your teen’s weight accompanied by feelings of sadness or low energy, a loss of appetite or sleeping problems, can indicate that he might suffer from depression. The nonprofit health advice site HelpGuide.org cautions that untreated depression can lead to poor school performance, drug or alcohol use, and even suicidal thoughts or tendencies. Medical practitioners can effectively treat depression with medications and therapy, so seek help for your teen as soon as you notice any signs of depression.
Sudden weight loss can be a red flag for eating disorders, such as anorexia nervosa and bulimia nervosa. People with these conditions experience a distorted body image, leading them to think they are too fat even when they are not. Your teen might exercise constantly to get into shape or she might weigh food before eating it or meticulously count the calories of everything she eats. Eating disorders require professional advice and treatment, so talk to your teen’s doctor if you notice any signs of these conditions.
As your teen nears the end of puberty, his growth will often taper off and normalize, making gaining or losing weight attributed to a growth spurt unlikely for most teens. He will also grow more accustomed to his new height and weight, which can make him less self-conscious about his weight and size.