How do you talk to a child about weight without causing harm?

Largely by not talking about weight — the evidence is unusually consistent that conversations focused on a child's weight are associated with worse outcomes, including disordered eating, while conversations focused on health behaviours are not.

What the research finds:

Weight-focused talk by parents — commenting on a child's size, encouraging dieting, or discussing your own weight critically — is associated with higher risk of disordered eating, body dissatisfaction and, notably, higher weight over time. The intended effect and the observed effect run in opposite directions.

Health-focused talk about eating well, moving and sleeping, without reference to weight or appearance, is not associated with those harms.

Teasing about weight, including from family, is one of the strongest predictors of later disordered eating.

What to do instead:

Change the environment, not the child. What is in the house, what is offered, when meals happen, and what activity is available are parental decisions that require no conversation with the child at all. This is where the leverage is.

Use the division of responsibility: the parent decides what, when and where food is offered; the child decides whether and how much to eat. It reduces mealtime conflict substantially and supports self-regulation.

Never restrict food as a rule or use it as reward or punishment, since restriction reliably increases preoccupation.

Focus activity on enjoyment and capability, not calories.

Watch your own language about your body, which children absorb directly.

Do not comment on anyone's appearance, including approvingly — praising weight loss teaches that bodies are evaluated.

Address the environment outside the home, including teasing, which needs adult intervention.

When to involve a professional: rapid change in weight or eating behaviour, food avoidance, distress about body, excessive exercise, or your own concern. Ask for a clinician who works without weight-centric framing, and note that eating disorders occur at every body size and are frequently missed in children who are not underweight.

General information, not medical advice.