No. Waiting for your child to bring up weight concerns for fear of creating self-esteem issues is not wise. Overweight and obesity is a medical concern and should not be ignored. By intervening you have the chance to improve current and future health and emotional well-being.
Chances are your child has been teased and is already aware of her overweight status. Children can be hurtful, so if your child is overweight, you should assume some school mate has told her so. Children are often embarrassed or ashamed about teasing and do not want to report it to parents. Children also internalize embarrassment about being picked last for sports teams or not being asked to dance at school dances. All of these situations make children aware of their weight, even if they never discuss it with you.
Children as young as 7 or 8 understand the concept of being overweight and you can have a discussion about weight beginning at this age. Older children may even tell you they are overweight if asked. Any discussion should focus on being healthier, feeling better, and being more active. Never sound accusatory or cast blame and never focus on weight.
Be confident that if your child feels valued, loved and supported, then bringing up weight issues will not harm self-esteem, which is a function of being valued. What can harm self-esteem is relentless teasing about weight, physical appearance, and not being able to keep up physically with peers. These long-term damages are a greater threat to self-esteem than any compassionate, low-key discussion of weight management by a loving, supportive parent.
A telling study at UC San Diego showed that children who were overweight rated their personal happiness at a similar level as pediatric patients undergoing chemotherapy treatment. Many overweight/obese children are anxious, unhappy or depressed, so giving your child the chance to improve her quality of life should never be viewed as upsetting, but rather as empowering.