Research

Hormonal

Postnatal catch-up growth (defined as a weight SD score gain >0.67 between birth and two years) in children who were small or thin at birth is a significant risk factor for increased body mass index, percentage body fat, and central fat distribution (waist circumference) by five years of age.

If your baby was born small or thin but gains weight rapidly during the first two years of life, they are at a higher risk of being overweight or having higher body fat by age five. This does not mean you should restrict food, but it suggests that monitoring their growth trajectory and maintaining a healthy lifestyle as they grow is important to mitigate long-term metabolic risks.

GoodSupportsHIGH confidence
Children who showed catch-up growth between zero and two years were heavier, taller, and fatter (body mass index, percentage body fat, and waist circumference) at five years than other children.
K. K L Ong · BMJ · 2000

Why this rating

Prospective cohort study with a large sample size (n=848) and rigorous longitudinal measurements, though observational design limits causal inference.

Source

Association between postnatal catch-up growth and obesity in childhood: prospective cohort study

K. K L Ong · BMJ · 2000

DOI 10.1136/bmj.320.7240.967

cohort · n=848Cited 1,667×
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DOI resolved against Crossref · corpus check 2026-06-10

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