Body dissatisfaction among adolescent girls is common enough that it is close to normative in survey data, and it is associated with depressive symptoms, disordered eating and avoidance of physical activity.
Schools have responded with a range of programmes. Their evaluation is more informative than their prevalence, because the programmes vary considerably in whether they work.
What has evidence
Dissonance-based interventions. These have the strongest evidence base in the field. Participants voluntarily argue against the thin ideal — writing, speaking and role-playing in opposition to it — which produces attitude change through the discomfort of arguing against a belief one partly holds.
Randomised trials have found reductions in body dissatisfaction and in eating disorder risk factors, with effects sustained at follow-up in several studies. It is among the better-evidenced prevention programmes in adolescent mental health generally.
The mechanism is worth noting: it requires active participation rather than receiving information, which is a recurring feature of interventions that work.
Media literacy. Programmes teaching critical analysis of media images have reasonable evidence, particularly where they involve active analysis rather than passive instruction. Effects are smaller than dissonance-based approaches but consistently positive.
Cognitive-behavioural approaches. Effective in treatment contexts and reasonably supported in prevention, though more resource-intensive to deliver.
What does not work
Psychoeducational programmes that provide information about eating disorders. Evaluations have generally found little or no effect on behaviour, and there has been longstanding concern in the field about iatrogenic effects — specifically, that detailed description of disordered eating behaviours can function as instruction.
This concern has shaped guidance considerably. Prevention guidance now generally recommends against detailed description of methods, weights or behaviours.
One-off assemblies and talks. The same finding as everywhere else in this field. Single exposures produce short-lived attitude change and no behavioural effect.
Programmes centred on a person recounting their own eating disorder in detail. This format is popular, emotionally powerful, and specifically cautioned against in professional guidance for the reasons above.
The measurement problem in this literature
Most evaluations measure body satisfaction on self-report scales at short follow-up. Few measure behaviour, and very few measure clinical outcomes.
An intervention that improves scores on a questionnaire six weeks later has demonstrated something real but limited. Whether it reduces the incidence of eating disorders is a much harder question requiring much larger samples and longer follow-up, and it has rarely been answered.
This should temper confidence in the whole area, including the positive findings.
The social media question
The relationship between social media use and body image is one of the most-studied and most-contested questions in adolescent research.
What is reasonably well supported: appearance-focused social media use is associated with body dissatisfaction more strongly than general use; the mechanism appears to involve appearance comparison rather than screen time; and image-based platforms show stronger associations than text-based ones.
What is less well supported: claims about the size of the effect. Large-scale analyses have generally found associations that are statistically significant and small in magnitude, and the debate about how to interpret those effect sizes is genuine and unresolved.
What is better supported than the average effect is heterogeneity — the same use appears to affect some adolescents considerably more than others, with pre-existing body dissatisfaction being a strong moderator.
That heterogeneity implies targeted rather than universal responses, which is the opposite of most policy proposals in this area.
What schools and families can do that has support
Reduce appearance-focused talk in the environment. Adults commenting on their own or others' bodies, including approvingly, models appearance evaluation. Studies of family communication find associations between appearance-focused parental comment and adolescent body dissatisfaction, including for positive comments.
Focus physical activity on function rather than appearance. Programmes framing exercise in terms of capability rather than body change have reported better engagement and better body image outcomes.
Address the environments where the comparison happens, particularly changing facilities and kit, which recur in the sport participation research for exactly this reason.
Use programmes with evidence and avoid the formats specifically cautioned against, which requires someone to check rather than to accept an offered assembly.
The honest summary
Prevention in this area works better than nothing and considerably less well than its advocates suggest. The best-evidenced approach requires active participation over multiple sessions and is therefore the least frequently delivered.
And the most common format — an assembly featuring a personal account — is the one with the weakest evidence and the clearest theoretical risk, which is a reasonably good illustration of how programme selection works in practice.