What is overweight for a 10-year-old?

Why do BMI thresholds for children differ from adults?

For adults, fixed BMI cut-offs apply: 25 for overweight and 30 for obesity. However, children grow in spurts, and body composition changes continuously — especially during puberty. This is why the adult scale does not work for children. A 10-year-old with a BMI of 22 may well fall into the obesity range, whereas the same BMI in an adult is a healthy weight.

The solution is age-adjusted cut-offs. The most widely used in Swedish healthcare were developed by the International Obesity Task Force (IOTF) and are called IOTF-25 (the cut-off for overweight) and IOTF-30 (the cut-off for obesity). These cut-offs have been calculated to correspond to an adult BMI of 25 and BMI of 30 — but adjusted separately for each age and sex.

Approximate BMI thresholds for overweight at 10 years of age

The IOTF thresholds for 10-year-olds are approximately as follows:

• Boys, 10 years: Overweight = BMI ≥ 19.8. Obesity = BMI ≥ 24.0.
• Girls, 10 years: Overweight = BMI ≥ 19.9. Obesity = BMI ≥ 24.1.

A practical example: a boy who is 140 cm tall and weighs 40 kg has a BMI of 20.4 — slightly above the overweight threshold. If he weighs 47 kg, he falls into the obesity range.

Even so, these numbers can be misleading without context. A 10-year-old who is well into puberty may have a temporarily higher BMI that later evens out as height catches up.

What iso-BMI shows

Iso-BMI is a conversion that makes a child's BMI comparable to an adult BMI. This is the figure used in Swedish medical records:

• Iso-BMI 18.5–24.9 = healthy weight
• Iso-BMI 25–29.9 = overweight
• Iso-BMI 30–34.9 = class 1 obesity
• Iso-BMI 35–39.9 = class 2 obesity
• Iso-BMI ≥ 40 = class 3 obesity (severe childhood obesity)

BVC (child health centres) and elevhälsan (the school health service) calculate iso-BMI automatically based on the child's height, weight, age, and sex. You can also calculate iso-BMI for your child here.

The trend over time is more important than a single reading

A BMI reading that borders on overweight tells you very little on its own. What healthcare professionals look at is the child's BMI growth chart:

• Is the chart following its usual trend? Then there is usually no major cause for concern, even if the value is high.
• Has the curve broken its trend and started climbing more steeply? This is an early warning sign, even if iso-BMI is still below 25.
• Has iso-BMI crossed 25 and continued upward? Contact BVC, elevhälsan, or your primary care centre.

The BMI growth chart is an important pedagogical tool. Many parents find it less judgmental than raw numbers, as it shows development over time rather than a comparison against an "ideal".

What happens with overweight (not obesity)?

Overweight in children is not a disease in itself — but it can be a step towards obesity if the trend is not reversed. Swedish clinical practice according to Rikshandboken i barnhälsovård is to offer guided family consultations as early as when BMI is rising or overweight is present, focusing on family routines, eating habits, and physical activity.

It is rarely appropriate to refer children with overweight alone to specialist care, but if comorbidities are present (such as high blood pressure, liver involvement, or sleep apnoea) or if there is a strong family history, an evaluation may be carried out sooner.

What happens with obesity in a 10-year-old?

If iso-BMI is in the obesity range (30 or higher), the child should be assessed by a doctor. At BUMM (paediatric outpatient clinic), a comprehensive investigation is conducted:

• Blood tests for type 2 diabetes, blood lipids, liver function, and thyroid function.
• Blood pressure measurement.
• Questions regarding family history, dietary habits, physical activity, sleep, and mental health.
• If necessary, sleep studies, liver ultrasound, or other targeted investigations.

A treatment plan is then drawn up, founded on combined lifestyle treatment for the entire family. In some cases, medication may be considered, but only within specialist care and generally from 12 years of age for most approved products (one GLP-1 medication is approved from 6 years of age for specific indications).

Rely on healthcare, not rumours

There is a great deal of information about childhood obesity online that is inaccurate, moralising, or commercially motivated. Primary sources to trust include 1177 Vårdguiden, Rikshandboken i barnhälsovård, Folkhälsomyndigheten, Socialstyrelsen (National Board of Health and Welfare), and Rikscentrum Barnobesitas. Your BVC, elevhälsan, and BUMM will always make an assessment based on your child's individual growth chart — not on a generic weight table.

Related questions

• What is a normal weight for a 10-year-old child?There is no single 'normal' weight figure — here is how iso-BMI works for a 10-year-old.
• What is a normal weight for a 12-year-old?Puberty, height and sex all play a part — this is how a 12-year-old's weight is assessed.
• When is overweight in children something to take seriously?The patterns that signal overweight needs investigation — and where to seek help.

See all questions and answers →