BMI is not interpreted the same way in children and adults. In full growth, corpulence evolves naturally with age. This is why we use growth curves, which follow the evolution of BMI over time. Properly understood, they are a valuable prevention tool.
1. Why curves rather than a threshold
In children, BMI varies naturally as they grow: it drops in early childhood, then rises again. A fixed threshold would therefore not make sense. The growth curves, present in the health record, locate the child's BMI in relation to their age and to a reference population.
2. Read a growth chart
What matters is not just a point, but the trajectory of the curve over time. A curve that regularly follows its corridor is reassuring. A change of direction (breakage or acceleration) deserves attention and medical advice.
| Observation | Interpretation |
|---|---|
| Regular curve | harmonious development |
| Early adiposity rebound | Attention point |
| Curve break | To be medically evaluated |
3. The adiposity rebound
Around age 6, the BMI normally starts to rise again: this is the “adiposity rebound”. If it occurs too early, it can herald an increased risk of later overweight. This marker, visible on the curve, helps to act early if necessary.
4. Support without dramatizing
The objective of monitoring is not to make a child lose weight at all costs, but to support harmonious growth. We favor good family habits: balanced diet, physical activity, sleep, limitation of screens, in a caring climate without stigma.
- Have the curve monitored regularly by a professional
- Encourage active play and limit screen time
- Promote balanced meals as a family
The doctor or pediatrician interprets the curves and advises families on a case-by-case basis.
💡 tips to remember
- In children, BMI varies naturally with growth: we use curves rather than a fixed threshold.
- It is the trajectory of the curve over time that counts: a regular curve is reassuring, a break merits medical advice.
- The rebound in adiposity towards 6 years is normal; if it occurs too early, it can indicate an increased risk of being overweight.
- The objective is not to make the child lose weight but to support harmonious growth, without stigmatization.
- Balanced diet, active play, sleep and limitation of screens, in a caring climate, are the best allies.
