Key Points at a Glance
- Weight in children and adolescents is assessed using age- and sex-specific BMI percentiles.
- Growth, puberty, weight development, fat distribution, and related health conditions also matter.
- Excess weight usually results from several interacting factors, not a lack of discipline.
- Possible effects include metabolic, blood pressure, sleep, joint, and mental health problems.
- Treatment should be age-appropriate, multidisciplinary, and free from shame.
- The Body Clinic assesses adolescents from age 12; younger children should receive pediatric care.
Overweight in children and adolescents is a sensitive topic. During growth and puberty, body weight or a single BMI value is not enough to assess possible health risks reliably.
This article explains how BMI percentiles are interpreted, which physical and psychological factors matter, and when medical support may be appropriate. Overweight is not a question of blame or discipline, but usually develops through a combination of biological and social factors.
What does overweight mean in children and adolescents?
Overweight means that body weight is higher than medically expected in relation to height. In adults, the body mass index, or BMI, is usually used for this. In children and adolescents, the assessment is more complex because they are still growing.
A 13-year-old may be in the middle of a growth spurt. Another child may not have entered puberty yet. Some adolescents gain weight first and then grow in height. Others develop a clear increase in abdominal fat or already show health-related abnormalities.
That is why overweight in children and adolescents should not be assessed only by appearance or body weight. Medically relevant factors include:
- BMI percentile for age and sex,
- weight development over time,
- waist circumference and fat distribution,
- pubertal development and growth,
- blood pressure, blood sugar, blood lipids and liver values,
- sleep, movement, nutrition and emotional distress,
- family history, for example obesity, diabetes or high blood pressure.
Language also matters. Children and adolescents notice very clearly whether people talk about them or with them. Shaming comments, pressure or constant weight monitoring can harm eating behavior, self-esteem and trust.
BMI percentiles explained simply
BMI is calculated in children and adolescents in the same way as in adults: body weight divided by height squared. But the interpretation is different. The reason is simple: children and adolescents are still growing. Height, weight, muscle mass and fat distribution change depending on age, sex and puberty stage.
That is why a fixed BMI cut-off, as used in adults, is not sufficient for children and adolescents. Instead, BMI is compared with percentile curves. These show how a child’s or adolescent’s BMI compares with peers of the same age and sex.
Example: two adolescents can have the same BMI, but be assessed differently if they are different ages or at different stages of puberty. A value that is less notable in a 17-year-old may already be clearly above the expected range in a 12-year-old.
For medical assessment, it is therefore not just one BMI value that matters, but also development over time. For example, it is important whether an adolescent has been growing along a similar percentile curve for years or whether BMI suddenly moves sharply upward.
| Term | What it means | How parents can understand it |
|---|---|---|
| 50th percentile | BMI is roughly in the middle of the comparison group. | About half of peers are below it and about half are above it. |
| 90th percentile | BMI is higher than in about 90 percent of peers. | This can indicate overweight and should be assessed over time. |
| 97th percentile | BMI is higher than in about 97 percent of peers. | This indicates obesity and should be medically assessed. |
| 99.5th percentile | BMI is very clearly above the comparison group. | Specialized medical assessment is particularly important. |
Percentiles are not a judgment about a child. They are a medical tool to better assess growth and weight in relation to age and sex. They do not show on their own whether someone is healthy or ill. For that, physical examination, development over time, blood values, blood pressure, sleep, movement, eating behavior and emotional distress also need to be considered.
The EMA explains the principle using the 95th percentile: a BMI at or above the 95th percentile means that the BMI is higher than in 95 percent of people of the same age and sex. According to the EMA, Wegovy is described for adolescents from age 12 with obesity when BMI is at or above the 95th percentile and body weight is over 60 kg.
Overweight by age group: what matters at each stage
Overweight does not mean the same thing at every age. In a preschool child, the focus is mainly on growth, family routines and pediatric care. In adolescents, puberty, self-image, psychological distress, personal responsibility and medical complications become more important.
Children and adolescents should therefore not all be treated the same way. The following age groups can help put the situation into better context.
Toddlers and preschoolers: observe without shame
In younger children, the main focus is not weight loss, but growth, development and a healthy everyday routine. Often, the goal is to observe weight development, improve routines and relieve parents.
At this age, parents should not work with diets, calorie counting or weight pressure. Regular meals, sufficient sleep, everyday movement, fewer sugar-sweetened drinks and a relaxed eating environment are more important.
Pediatric assessment is useful if weight increases much faster than height, if the child has symptoms or if diabetes, severe overweight or cardiovascular disease are common in the family.
For children under 12, the first step should usually be a pediatrician. The goal is not to put the child on a diet, but to assess growth, development, everyday life and possible risks carefully.
School-age children: family, school and routines
In school-age children, daily life changes significantly. Children sit for longer periods, have fixed school hours, eat outside the home, compare themselves more strongly with others and sometimes experience the first negative comments about their body.
In this age group, family and school are especially important. Parents can make a major difference without turning the child into “the problem”: make healthier foods easier to access at home, strengthen shared meals, reduce sweetened drinks, support everyday movement and improve sleep routines.
Here too, the child should not be placed on a special diet. It is better when the whole family benefits from better routines.
Parents should seek pediatric advice if:
- weight rises much faster than height over several months,
- the child already shows abdominal weight gain, breathing problems, joint pain or severe fatigue,
- blood pressure, blood sugar or liver values are abnormal,
- strong food cravings, secret eating or emotional eating are noticeable,
- overweight, diabetes or cardiovascular diseases are common in the family,
- the child is teased because of weight or withdraws socially.
Adolescents from 12: medical assessment becomes more important
From around age 12, medical assessment becomes more important. Puberty, hormones, body image, media use, stress, school life and psychological distress can strongly affect weight and eating behavior.
Adolescents want to be taken seriously. A meaningful treatment approach should therefore not be controlled only by parents, but should actively involve the adolescent. It is about realistic goals, medical risks, eating behavior, movement, sleep, self-esteem and everyday life.
In adolescents from age 12, medical treatment options may also be assessed in cases of obesity. This does not automatically mean that medication is necessary or suitable. It only means that in cases of severe overweight, comorbidities or ongoing distress, structured medical assessment may be useful.
For some adolescents, weight stabilization is initially a more sensible goal than rapid weight loss. If growth is still ongoing, stable weight development combined with height growth can already be medically relevant.
Young adults: transition into adulthood
In older adolescents and young adults, responsibility changes again. Training, university, first jobs, moving away from home, irregular meals, alcohol, stress and less fixed daily structure can influence weight and metabolism.
In this phase, it is important that treatment does not only work in the short term, but fits everyday life. This includes realistic meal planning, movement despite limited time, psychological stability, medical follow-up and a strategy that remains sustainable after initial weight loss.
Causes: why overweight can develop
Overweight rarely has just one cause. Several factors usually come together. That is why simply banning individual foods or telling adolescents to have more discipline is not helpful.
Genetic predisposition
Genetic predisposition plays an important role. If parents or close relatives live with overweight, obesity or metabolic disease, the risk for children and adolescents can also increase. This does not mean that overweight is unavoidable. It means that some adolescents have to work much harder against hunger, appetite, weight gain or rapid relapse than others.
Nutrition and everyday life
Often, it is not simply about “eating too much,” but about meal structure, available foods, snacks, drinks, school routines, delivery food, emotional eating or very irregular meals.
Particularly relevant factors include:
- sugar-sweetened drinks, energy drinks, juices or sweetened coffee drinks,
- frequent snacking on the side,
- large portions of very energy-dense foods,
- skipping meals and eating a lot later in the evening,
- eating out of boredom, stress, frustration or loneliness,
- lack of planning for school, training or free time.
Movement, screen time and sleep
Children and adolescents often spend many hours sitting: school, homework, phone, gaming, streaming, social media. At the same time, organized movement decreases for some adolescents, especially if they feel uncomfortable in their body or have had negative experiences in school sports.
Sleep also matters. Too little sleep can affect hunger, appetite, mood and energy. Those who are constantly tired often move less and are more likely to reach for quick, energy-dense foods.
Psychological distress
Stress, bullying, performance pressure, family conflict, loneliness, depression or anxiety can affect weight and eating behavior. Conversely, overweight itself can become emotionally distressing. This can create a cycle of shame, withdrawal, emotional eating and less movement.
Especially important: if binge eating, secret eating, strong loss of control, vomiting, extreme calorie counting or intense fear of weight gain occur, the conversation should not be only about weight. Careful medical and psychological assessment is needed.
Medical conditions and medication
More rarely, medical conditions or medications can contribute to weight gain. These include thyroid disease, rare hormonal disorders, genetic syndromes, certain psychiatric medications, corticosteroid therapy or other medications.
This is not the most common reason, but it should be medically assessed if weight increases very rapidly, growth or puberty appear unusual, or additional symptoms occur.
Possible consequences: physical and psychological
Overweight and obesity can have health consequences already in childhood and adolescence. Not every child with overweight automatically has complications. But the more severe and longer-lasting the overweight is, the more important assessment becomes.
| Area | Possible consequence | What to consider |
|---|---|---|
| Metabolism | Insulin resistance, prediabetes, type 2 diabetes | Check blood sugar, HbA1c and family history. |
| Cardiovascular system | High blood pressure, elevated blood lipids | Monitor blood pressure and lipid values regularly. |
| Liver | Fatty liver disease | Check liver values and, if needed, ultrasound. |
| Sleep | Snoring, sleep apnea, daytime fatigue | Take sleep quality and breathing pauses seriously. |
| Musculoskeletal system | Knee, hip, foot or back pain | Build movement gradually and in a joint-friendly way. |
| Mental health | Shame, withdrawal, depression, anxiety, eating disorders | Address not only weight, but also self-esteem and daily life. |
Adolescents in particular often do not say on their own how distressing the topic is. That is why consultations should ask sensitively: How is school? Is there bullying? Is sport avoided? Are there binge episodes? Is there secret eating? Is there fear of losing control?
Diagnostics: what should be medically assessed
Good diagnostics are more than weighing and measuring. They should clarify whether overweight has already led to health consequences, whether certain causes contribute and which treatment path makes sense.
Typical parts of medical assessment include:
- height, weight and BMI percentile,
- weight development over recent months or years,
- waist circumference and fat distribution,
- blood pressure measurement,
- blood sugar, HbA1c and, if appropriate, assessment of insulin resistance,
- blood lipids,
- liver values,
- assessment of sleep problems or snoring,
- medications and pre-existing conditions,
- psychological distress, eating behavior and possible eating disorder.
Depending on the findings, additional pediatric, endocrinological, diabetological, nutritional, psychotherapeutic or sleep medicine assessment may be useful.
Treatment: which paths may make sense
Treatment of overweight and obesity in children and adolescents should be multimodal. This means that nutrition, movement, behavior, family, sleep and mental health are considered together.
Nutrition: practical instead of diet mode
Adolescents do not need a crash diet. Rules that are too strict can increase cravings, loss of control and shame. A structured, nutrient-rich diet that works with school, training, family and free time is more useful.
Helpful steps can include:
- regular meals instead of constant snacking,
- protein-rich foods in main meals,
- vegetables, fruit, whole grains and legumes,
- water or unsweetened drinks instead of soft drinks and energy drinks,
- a conscious approach to sweets instead of complete bans,
- planning for school, training or time away from home.
If strong emotional eating or binge eating is present, nutrition should not be viewed in isolation. Psychological support can then be important.
Movement: avoid shame and make it fit
Movement does not have to mean joining a sports club, running or going to a gym right away. For adolescents with severe overweight, joint-friendly and low-threshold activities may be better.
Suitable options can include:
- walking, cycling or swimming,
- short bodyweight strength exercises,
- physiotherapy if there is pain or uncertainty,
- dancing, team sports or martial arts if they are enjoyable,
- more everyday movement, for example walking or cycling short distances.
Avoiding negative experiences is important. Those who were teased in school sports often need to rebuild trust in movement first.
Behavior, sleep and stress
Weight is strongly connected to routines. These include sleep times, media use, stress management, meal planning, shopping, family rhythm and dealing with emotions.
Adolescents often benefit from small and concrete goals:
- one fixed breakfast option on school days,
- one sugar-free drink as the standard choice,
- two fixed movement sessions per week,
- a phone-free sleep routine,
- a plan for snacks after school.
These changes may seem unspectacular, but they are often more sustainable than big resolutions.
Medication and weight-loss injections in adolescents
Medication can play a role in certain adolescents with obesity. However, it is never the first and only step. It always requires medical assessment, a clear indication and accompanying changes in nutrition, movement and everyday life.
In Europe, some medications for weight management are described for adolescents or certain age groups. According to the EMA, Wegovy is indicated for adolescents from age 12 with a BMI at or above the 95th percentile and body weight over 60 kg.4 Saxenda is indicated for adolescents from age 12 who weigh more than 60 kg and for certain children from age 6 who weigh at least 45 kg.5 Mounjaro is currently indicated for weight management in adults.6
In practice, this means: a medication name alone is not enough. The decisive question is whether treatment is suitable for the individual situation, whether risks exist, which comorbidities are present and whether long-term support is possible.
In adolescents, the following must be considered especially carefully:
- age, growth and pubertal development,
- BMI percentile and severity of obesity,
- comorbidities such as high blood pressure, insulin resistance or fatty liver disease,
- psychological distress and eating disorder risk,
- motivation and understanding of the adolescent,
- consent of guardians,
- regular medical follow-up.
You can learn more about medical options on our page about weight-loss medication. Information on GLP-1-based treatment is also available on our page weight loss with injections.
The role of the family: support without pressure
Family is central when overweight occurs in childhood or adolescence. But that does not mean parents should control, comment or constantly remind. Often, the opposite is more helpful: less pressure, more structure.
Supportive steps include:
- shared meals without weight comments,
- planning foods at home so healthier choices become easier,
- no special diet for only one child,
- movement as a shared activity rather than punishment,
- no negative comments about bodies, weight or food,
- open conversations about stress, school and bullying,
- not waiting until everything escalates before seeking medical help.
Especially with adolescents, it is important that they are allowed to participate in decisions. Those who only receive instructions often resist. Those who understand why a step is useful can take responsibility more easily.
The Body Clinic: medical assessment from age 12
The Body Clinic supports adolescents from age 12 if medical eligibility is present and physician-led treatment may be appropriate. Younger children should be cared for through pediatric medicine.
With adolescents, the goal is not rapid weight loss or fulfilling a medication request. The decisive factor is medical assessment: How severe is the overweight? Are comorbidities present? Are there contraindications? How stable is eating behavior? What role do school, sleep, stress, family and everyday life play?
Treatment may take place without medication or with medication support, depending on the situation. What matters is always a structured plan with medical supervision, nutrition, coaching and follow-up.
If you would first like general information, you can find more on our page about medically supervised weight loss.
Frequently Asked Questions
When is a child considered overweight?
In children and adolescents, overweight is not assessed using the fixed BMI cut-offs for adults. Age- and sex-specific BMI percentiles are decisive. Overweight typically begins at the 90th percentile, obesity at the 97th percentile.
What does BMI percentile mean in children?
A BMI percentile shows how a child’s or adolescent’s BMI compares with peers of the same age and sex. The 90th percentile means, for example, that BMI is higher than in about 90 out of 100 comparable children or adolescents.
Is overweight in adolescents just a phase?
Sometimes weight changes during growth and puberty. But if BMI is clearly above the age-related range, weight rises quickly or symptoms occur, it should be medically assessed.
What are typical causes of overweight in adolescents?
Several factors often interact: genetic predisposition, nutrition, lack of movement, lack of sleep, stress, psychological distress, media use, family, school, medications or rare medical conditions.
What consequences can overweight have in adolescents?
Possible consequences include high blood pressure, elevated blood lipids, insulin resistance, prediabetes, type 2 diabetes, fatty liver disease, sleep apnea, joint symptoms and psychological distress such as shame, withdrawal or depression.
Can weight-loss injections be used in adolescents?
In selected adolescents with obesity, medication-based treatment can be medically assessed. Requirements include age, indication, risk assessment, medical supervision and an overall concept involving nutrition, movement and behavior. Not every medication is approved or suitable for adolescents.
Does The Body Clinic treat children and adolescents?
The Body Clinic treats adolescents from age 12 if medical eligibility is present. Children under 12 should be assessed by pediatricians or specialized pediatric services.
What can parents do without creating pressure?
Helpful steps include shared routines, regular meals, fewer sugar-sweetened drinks, more everyday movement, respectful language and support with stress or bullying. Pressure, shame and constant weight monitoring are usually counterproductive.
When should parents seek medical help for overweight?
Medical help is useful in cases of severe or rapidly increasing overweight, high blood pressure, abnormal blood values, sleep problems, joint pain, binge eating, significant emotional distress or family history of diabetes and cardiovascular disease.
Conclusion: overweight in children and adolescents needs sensitive medical assessment
Overweight in children and adolescents should be neither dramatized nor downplayed. What matters is professional assessment: How severe is the overweight? How is BMI developing over time? Are there physical or psychological factors? Which support fits the age and life situation?
In younger children, the family and pediatric environment are especially important. In adolescents, autonomy, puberty, body image, school, media, psychological distress and personal responsibility become more relevant.
Good treatment does not rely on blame or quick diets. It relies on structure, medical diagnostics, nutrition, movement, behavior, sleep, family and, in selected adolescents, medically assessed medication options.
The Body Clinic can medically assess adolescents from age 12 and review which treatment path may make sense. The person remains the focus, not only the BMI.
Sources
- German Obesity Society: New S3 guideline for prevention and treatment of obesity in childhood and adolescence. Information on prevalence, care and multimodal therapy.
- AWMF guideline register: Treatment and prevention of obesity in childhood and adolescence, register number 050-002. Guideline on diagnostics, prevention and therapy.
- German Federal Ministry of Health: Prevention of overweight in children and adolescents. Information on prevalence, causes, prevention and health consequences.
- European Medicines Agency: Wegovy EPAR. Information on semaglutide, indication and study data in adults and adolescents.
- European Medicines Agency: Saxenda EPAR. Information on liraglutide, indication and study data.
- European Medicines Agency: Mounjaro EPAR. Information on tirzepatide and indication for weight management in adults.
Transparency notice: This article was prepared with the support of artificial intelligence. The content, sources, and wording were reviewed by the editorial team.