It's difficult to say whether 40 kg is "OK" for a 13-year-old girl without more information. A healthy weight for a teenager depends on several factors, including:
- Height: A taller girl will naturally weigh more than a shorter girl.
- Body composition: Muscle weighs more than fat. A girl with more muscle mass may weigh more than a girl with more body fat, even if they are the same height.
- Age: A 13-year-old is still growing and developing, so her weight will fluctuate.
Instead of focusing on a specific number, it's more important to consider overall health and well-being. A doctor or registered dietitian can help determine if a 13-year-old girl's weight is within a healthy range for her individual needs.
Here are some resources for more information:
- The National Institutes of Health: https://www.nih.gov/
- The American Academy of Pediatrics: https://www.aap.org/
