Influence of Feeding Types during the First Months of Life on Calciuria Levels in Healthy Infants: A Secondary Analysis from a Randomized Clinical Trial.

BACKGROUND/AIMS: Dietary factors can modify calciuria. We aim to investigate urinary calcium excretion in healthy infants according to their protein. METHODS: Secondary data analysis from a randomized clinical trial where healthy term infants were randomized after birth to a higher (HP) or lower (LP) protein content formula that was consumed until age 1 year. A non-randomized group of breastfed (BF) infants was used for reference. Anthropometry, dietary intakes and calciuria (calcium/creatinine ratios) from spot urine samples were assessed at ages 3 and 6 months. At 6 months, the kidney volumes were assessed using ultrasonography, and the serum urea and creatinine levels were determined. RESULTS: BF infants showed the highest calciuria levels, followed by the HP and the LP groups (p < 0.001 for all comparisons). Either protein intakes or formula types modulated the calciuria in linear regression models adjusted for other influencing dietary factors. The usual cut-off values classified 37.8% (BF), 16.8% (HP) and 4.9% (LP) of the infants as hypercalciuric. CONCLUSIONS: Feeding types during the first months of life affect calciuria, with BF infants presenting the highest levels. We propose new cut-off values, based on feeding types, to prevent the overestimation in hypercalciuria diagnoses among BF infants.

Infant feeding and later obesity risk.

Some 30 years ago, Günter Dörner proposed that exposure to hormones, metabolites and neurotransmitters during limited, sensitive periods of early development exert programming effects on disease risk in human adults. Early programming of long term health has since received broad scientific support and attention. For example, evidence increases for programming effects of infant feeding choices on later obesity risk. Meta-analyses of observational studies indicate that breast feeding reduces the odds ratio for obesity at school age by about 20%, relative to formula feeding, even after adjustment for biological and sociodemographic confounding variables. We hypothesized that breast feeding protects against later obesity by reducing the likelihood of high weight gain in infancy, and that this protection is caused at least partly by the lower protein supply with breast milk relative to standard infant formulae (the "Early Protein Hypothesis"). These hypotheses are tested in the European Childhood Obesity Project, a randomized double blind intervention trial in more than 1,000 infants in five European countries (Belgium, Germany, Italy, Poland, Spain). Formula fed infants were randomized to receive during the first year of life infant formulae and follow-on-formulae with higher or lower protein contents. Follow-up at 2 years of age shows that lower protein supply with formula normalizes early growth relative to a breast fed reference group and to the WHO growth reference. These results demonstrate that modification of infant feeding practice has an important potential for long-term health promotion and should prompt a review of the recommendations and policies for infant formula composition.

Lower protein in infant formula is associated with lower weight up to age 2 y: a randomized clinical trial.

BACKGROUND: Protein intake during infancy was associated with rapid early weight gain and later obesity in observational studies. OBJECTIVE: The objective was to test the hypothesis that higher protein intake in infancy leads to more rapid length and weight gain in the first 2 y of life. DESIGN: In a multicenter European study, 1138 healthy, formula-fed infants were randomly assigned to receive cow milk-based infant and follow-on formula with lower (1.77 and 2.2 g protein/100 kcal, respectively) or higher (2.9 and 4.4 g protein/100 kcal, respectively) protein contents for the first year. For comparison, 619 exclusively breastfed children were also followed. Weight, length, weight-for-length, and BMI were determined at inclusion and at 3, 6, 12, and 24 mo of age. The primary endpoints were length and weight at 24 mo of age, expressed as length and weight-for-length z scores based on the 2006 World Health Organization growth standards. RESULTS: Six hundred thirty-six children in the lower (n = 313) and higher (n = 323) protein formula groups and 298 children in the breastfed group were followed until 24 mo. Length was not different between randomized groups at any time. At 24 mo, the weight-for-length z score of infants in the lower protein formula group was 0.20 (0.06, 0.34) lower than that of the higher protein group and did not differ from that of the breastfed reference group. CONCLUSIONS: A higher protein content of infant formula is associated with higher weight in the first 2 y of life but has no effect on length. Lower protein intake in infancy might diminish the later risk of overweight and obesity. This trial was registered at clinicaltrials.gov as NCT00338689.

Can infant feeding choices modulate later obesity risk?

Since the concept of lasting programming effects on disease risk in human adults by the action of hormones, metabolites, and neurotransmitters during sensitive periods of early development was proposed >3 decades ago, ample supporting evidence has evolved from epidemiologic and experimental studies and clinical trials. For example, numerous studies have reported programming effects of infant feeding choices on later obesity. Three meta-analyses of observational studies found that obesity risk at school age was reduced by 15-25% with early breastfeeding compared with formula feeding. We proposed that breastfeeding protects against later obesity by reducing the occurrence of high weight gain in infancy and that one causative factor is the lower protein content of human milk compared with most infant formula (the early protein hypothesis). We are testing this hypothesis in the European Childhood Obesity Project, a double-blind, randomized clinical trial that includes >1000 infants in 5 countries (Belgium, Germany, Italy, Poland, and Spain). We randomly assigned healthy infants who were born at term to receive for the first year infant formula and follow-on formula with higher or lower protein contents, respectively. The follow-up data obtained at age 2 y indicate that feeding formula with reduced protein content normalizes early growth relative to a breastfed reference group and the new World Health Organization growth standard, which may furnish a significant long-term protection against later obesity. We conclude that infant feeding practice has a high potential for long-term health effects, and the results obtained should stimulate the review of recommendations and policies for infant formula composition.