Characterization of the infant BMI peak: sex differences, birth year cohort effects, association with concurrent

Related Experiment Video

Updated: May 12, 2026

Assessment of Child Anthropometry in a Large Epidemiologic Study
09:36

Assessment of Child Anthropometry in a Large Epidemiologic Study

Published on: February 2, 2017

William Johnson1, Audrey C Choh, Miryoung Lee

  • 1MRC Unit for Lifelong Health and Ageing, 33 Bedford Place, London, UK.

American Journal of Human Biology : the Official Journal of the Human Biology Council
|April 23, 2013
PubMed

Insights

The infant BMI peak (AgePeak and BMIPeak) occurred earlier and was lower in recent birth cohorts. These traits are heritable, but AgePeak timing doesn't align with infant fat mass peaks.

Area of Science:

  • Pediatric endocrinology and growth
  • Human growth and development
  • Body composition analysis

Background:

  • The infant body mass index (BMI)-for-age curve exhibits a peak, a critical early growth trait.
  • Understanding the infant BMI peak's characteristics and influencing factors is essential for assessing healthy growth trajectories.

Purpose of the Study:

  • To characterize the infant BMI peak, specifically AgePeak (age at peak BMI) and BMIPeak (peak BMI value).
  • To examine the influence of sex and birth cohort on AgePeak and BMIPeak.
  • To assess the heritability of these infant BMI peak parameters.

Main Methods:

  • Constructed BMI-for-age curves for 747 participants in the Fels Longitudinal Study.
  • Estimated individual AgePeak and BMIPeak using regression analysis.
  • Analyzed effects of sex and birth cohort (1929-2010) on AgePeak and BMIPeak.
  • Assessed heritability using variance components analysis and related BMIPeak to skinfold thickness.

Main Results:

  • AgePeak occurred at 9 months; BMIPeak was higher in boys (0.4 kg/m²).
  • Recent birth cohorts (1971-2010) showed an earlier AgePeak (1.5 months) and lower BMIPeak (0.35 kg/m²) compared to earlier cohorts (1929-1950).
  • Skinfold thickness explained significant variance in BMIPeak (37% in boys, 20% in girls); both traits were highly heritable (h²=0.54 for AgePeak, h²=0.75 for BMIPeak).

Conclusions:

  • Infant BMI peak parameters (AgePeak, BMIPeak) have decreased over successive birth cohorts.
  • While BMIPeak correlates with adiposity, AgePeak timing is not fully explained by infant fat mass peaks.
  • High heritability suggests a genetic component, necessitating further research into genetic control and body composition validation.
Abstract

More Related Videos

Quantified Assessment of Infant's Gross Motor Abilities Using a Multisensor Wearable09:24

Quantified Assessment of Infant's Gross Motor Abilities Using a Multisensor Wearable

Published on: May 17, 2024

Scanning Skeletal Remains for Bone Mineral Density in Forensic Contexts07:56

Scanning Skeletal Remains for Bone Mineral Density in Forensic Contexts

Published on: January 29, 2018

Related Concept Videos

Signs of Puberty01:27

Signs of Puberty

Puberty is a critical phase, typically beginning between the ages of 8 and 13 in girls and 9 and 14 in boys, though timing can vary based on genetics, environmental factors, and overall health. This period is characterized by the development of secondary sexual characteristics and the attainment of reproductive potential. Endocrine changes underpin puberty, with hormonal surges of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) instigated by Gonadotropin-Releasing Hormone (GnRH)...
Obesity01:24

Obesity

The Body Mass Index (BMI) is a numerical value derived from a person's weight and height, used to categorize individuals into weight ranges. It is calculated using the formula: weight in kilograms divided by height in meters squared. Obesity is a health condition characterized by excessive accumulation of adipose tissue that poses health risks, often diagnosed with a BMI ≥ 30. This excess fat storage occurs when surplus dietary calories are converted into triglycerides and stored in adipocytes...
Heritability01:06

Heritability

Heritability is a statistical concept that measures the degree to which genetic differences among individuals contribute to trait variations within a population. It is a fundamental idea in genetics, often prone to misinterpretation. Heritability is expressed as a percentage, reflecting the proportion of variation in a specific trait across a population that can be linked to genetic differences. However, it's important to understand that heritability does not determine how "genetic" a trait is,...
Regression Toward the Mean01:52

Regression Toward the Mean

Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when researchers try to extrapolate results...
Polygenic Traits01:18

Polygenic Traits

When more than one gene is responsible for a given phenotype, the trait is considered polygenic. Human height is a polygenic trait. Studies have uncovered hundreds of loci that influence height, and there are believed to be many more. Due to the high number of genes involved, as well as environmental and nutritional factors, height varies significantly within a given population. The distribution of height forms a bell-shaped curve, with relatively few individuals in the population at the...
Nature and Nurture01:10

Nature and Nurture

Many human characteristics, like height, are shaped by both nature—in other words, by our genes—and by nurture, or our environment. For example, chronic stress during childhood inhibits the production of growth hormones and consequently reduces bone growth and height. Scientists estimate that 70-90% of variation in height is due to genetic differences among individuals, and 10-30% of variation in height is due to differences in the environments that individuals experience, such as differences...