Energy utilisation of infants in Southern Brazil : breast-feeding pattern and socio-economic status in relation to obesity

The prevalence of obesity is increasing world-wide. The aetiology is complex: genetic factors, intake of energy dense foods, and lack of physical activity can only partly explain the increased prevalence. Originally, obesity was considered a problem mainly of the higher socio-economic class, but in countries undergoing the transition from a developing to an industrialised society, depending on the stage of transition obesity increasingly occurs in the lower socio-economic classes. An increased prevalence of obesity has also been observed in immigrant populations moving from a developing to an industrialised society. Recently, much attention has been given to the theory of metabolic programming. This theory proposes that metabolic characteristics are being developed during a critical window of time in early life, and these determine later health outcomes. Initially, the focus was on babies born with low birth weight indicating growth retardation in utero, and the subsequent catch-up growth early in life. More recently however, evidence is increasing that not only rapid growth of low birth weight babies, but also a period of rapid postnatal growth in full-term babies may be a risk factor for the development of glucose intolerance and obesity later in life. It is therefore highly important to monitor growth of infants and young children, and to apply recommendations of energy intake that result in a growth rate consistent with long term health.