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Fetal and early life growth and body mass index from birth to early adulthood in 1958 British cohort: longitudinal study

BMJ 2001; 323 doi: (Published 08 December 2001) Cite this as: BMJ 2001;323:1331
  1. Tessa J Parsons, research fellow (t.parsons{at},
  2. Chris Power, readera,
  3. Orly Manor, senior lecturerb
  1. a Department of Paediatric Epidemiology and Biostatistics, Institute of Child Health, London WC1N 1EH
  2. b School of Public Health and Community Medicine, Hebrew University, Jerusalem 91120, Israel
  1. Correspondence to: T Parsons
  • Accepted 29 June 2001


Objectives: To determine the influence of birth weight on body mass index at different stages of later life; whether this relation persists after accounting for potential confounding factors; and the role of indicators of fetal growth (birth weight relative to parental size) and childhood growth.

Design: Longitudinal study of the 1958 British birth cohort.

Setting: England, Scotland, and Wales.

Participants: All singletons born 3–9 March 1958 (10 683 participants with data available at age 33).

Main outcome measures: Body mass index at ages 7, 11, 16, 23, and 33 years.

Results: The relation between birth weight and body mass index was positive and weak, becoming more J shaped with increasing age. When adjustments were made for maternal weight, there was no relation between birth weight and body mass index at age 33. Indicators of poor fetal growth based on the mother's body size were not predictive, but the risk of adult obesity was higher among participants who had grown to a greater proportion of their eventual adult height by age 7. In men only, the effect of childhood growth was strongest in those with lower birth weights and, to a lesser extent, those born to lighter mothers.

Conclusions: Maternal weight (or body mass index) largely explains the association between birth weight and adult body mass index, and it may be a more important risk factor for obesity in the child than birth weight. Birth weight and maternal weight seem to modify the effect of childhood linear growth on adult obesity in men. Intergenerational associations between the mother's and her offspring's body mass index seem to underlie the well documented association between birth weight and body mass index. Other measures of fetal growth are needed for a fuller understanding of the role of the intrauterine environment in the development of obesity.

What is already known on this topic

What is already known on this topic Birth weight has been shown to be positively related to subsequent fatness

Few studies have investigated whether this relation is confounded by other factors, such as parental size

Birth weight may be an inadequate indicator of the intrauterine environment

What this study adds

What this study adds The relation between birth weight and adult body mass index was largely accounted for by mother's weight

Fetal growth indexed by birth weight relative to parental body size was unrelated to adult obesity

Rapid linear growth in childhood increased the risk of obesity in adulthood, especially in males with low birth weight

Among boys who grew rapidly, the risk of obesity in adulthood was similar for both lower and higher birth weights


  • Funding These analyses were funded by the Department of Health. The views expressed in this publication are those of the authors and not necessarily those of the sponsors.

  • Competing interests None declared.

  • Accepted 29 June 2001
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