There are critical periods during childhood that influence the development of obesity, including gestation and early infancy. Size at birth and early postnatal growth are determinants of adult height and body mass index.
Liggins Institute, University of Auckland, New Zealand researchers conducted a study to assess if birth weight has any effect on body composition and/or fat distribution in adolescents.
Study The effects of changes in nutrition on body composition of the growing animal depend on the timing, as well as severity, duration and nature, of the nutritional insult. In sheep, both maternal undernutrition around the time of conception and a high plane of nutrition in a young mother still growing herself result in impaired maternal metabolic adaptation to pregnancy, and hence greater substrate distribution to maternal at the expense of conceptus tissue accretion. Maternal nutrition in early pregnancy also determines subsequent growth and body composition of the offspring, with mild-moderate maternal undernutrition resulting in offspring of normal body weight at birth but with
Maternal nutrition in early pregnancy also determines subsequent growth and body composition of the offspring, with mild-moderate maternal undernutrition resulting in offspring of normal body weight at birth but with increased weight of fat depots thereafter. Undernutrition in late pregnancy commonly reduces offspring birthweight, and this in turn affects later growth and body composition. After birth, growth of different tissues is strongly influenced by both prior and current nutritional experiences. Lambs of lower birthweight take longer to start to gain weight after birth.
They also require a higher feed intake to attain a given weight gain, and more of that weight is gained as fat and less as muscle compared with lambs of higher birthweight. However for a given birthweight, slower postnatal weight gain is generally associated with a proportionately greater muscle growth. Rate of growth also determines other aspects of body composition.
Muscle fibre number, which limits final muscle size, is generally determined before birth, and indeed before the last trimester of pregnancy in many species. Lambs growing rapidly either before or after birth tend to have proportionately larger livers, whereas chronically slow growth is associated with reduced liver size relative to body weight. Similar patterns are seen in the lymphoreticular tissues such as spleen and thymus. It seems likely that these variations in body composition will have important functional consequences for later health and wellbeing.