Obesity poses short and long-term health risks for the individual. In terms of the burden on the health system, it is detrimental and costly. Health bodies have long been aware that to remedy obesity, lifestyle changes must be implemented within family members at an early age. There is also a growing body of evidence that nutrient composition of diet in the infant can have an impact on risk of obesity in later life. The European project CHOPIN investigated whether infant feeding regimes were responsible in part for the development of obesity as adults. Aspects of diet and lifestyle were researched by individual project partners. Specifically, the team based at the Children's Memorial Health Institute in Poland researched the effects of raised levels of proteins in an infant diet on growth factors, specifically those related to insulin. Blood, and or urine samples were taken from infants in four countries in Europe at three and six months of age. Infants fed on high protein formula feed were compared with those receiving a low protein formula diet. Serum concentrations of insulin-like growth factor (IGF-1) and IGF-BPs, the binding proteins that controls the distribution and activity of the growth factor were measured. As a measure of insulin secretion, urine levels of C-peptide/creatine ratios were monitored. Concentrations of a total of 18 amino acids in the blood were also measured. The data collected supports previous studies in that a high-protein formula feed stimulates the production of insulin-like growth factor. Because glucose levels were not elevated, higher insulin may be due to levels of some branched chain amino acids like leucine that are linked to production of the hormone. Higher amino acid levels found in serum could play an important role in insulin related metabolic activity and so be linked to a propensity towards obesity. Many health authorities have been encouraging mothers to breast feed their babies for many decades. The biochemical basis for this advice can help to reinforce the message and improve the health of nations as a whole.