Older children and teens who are wearing diapers face the same leakage issues as adults but are difficult to fit into adult sizes as their bodies are still growing. As many parents will attest, buying a smaller adult size with a compatible waist size doesn't guarantee a good fit on a teenager. Slim hips and legs and less body mass are typical of teens and sometimes elderly adults. This product is specially designed to fit young adults. Note: These pants are made to fit children over 10 years old. Please measure and use our size chart before ordering.