Infant fat mass and later child and adolescent health outcomes: a systematic review.

OBJECTIVE: Obesity and excess adiposity are leading causes of metabolic and cardiovascular morbidity and mortality. Early identification of individuals at risk is key for preventive strategies. We examined the relationship between infant body composition (0-2 years of age) and later (>2 years) health outcomes using a systematic review. DESIGN: We preregistered the study on PROSPERO (ID 288013) and searched Embase, PubMed and Cochrane databases for English language publications using the Medical Subject Headings (MeSH) terms 'infant' and 'body composition' and 'risk' between January 1946 and February 2022. We included studies which assessed infant body composition using predetermined in vivo methods other than body mass index (BMI). RESULTS: We identified 6015 articles. After abstract screening to assess eligibility, we reviewed 130 full text publications. 30 were included in the final assessment and narrative synthesis. Meta-analysis was not possible due to heterogeneity of results. All 30 studies were of high quality and reported associations between infant body composition and 19 different health outcomes after 2 years of age. Outcome measurements ranged from 2 years to 16 years. The strongest associations were found between infant fat mass and later fat mass (7 studies), and later BMI (5 studies). For 11 of the outcomes assessed, there was no relationship to infant adiposity detected. CONCLUSIONS: Current evidence, from a small number of studies, suggests a positive association between infant adiposity and future adiposity or BMI, but the validity of infant body composition as a biomarker of future health remains inconclusive. Carefully designed, standardised studies are required to identify the value of infant body composition for predicting later health. TRIAL REGISTRATION: PROSPERO: 288013.

Optimal Protein Intake in Healthy Children and Adolescents: Evaluating Current Evidence.

High protein intake might elicit beneficial or detrimental effects, depending on life stages and populations. While high protein intake in elder individuals can promote beneficial health effects, elevated protein intakes in infancy are discouraged, since they have been associated with obesity risks later in life. However, in children and adolescents (4-18 years), there is a scarcity of data assessing the effects of high protein intake later in life, despite protein intake being usually two- to three-fold higher than the recommendations in developed countries. This narrative review aimed to revise the available evidence on the long-term effects of protein intake in children and adolescents aged 4-18 years. Additionally, it discusses emerging techniques to assess protein metabolism in children, which suggest a need to reevaluate current recommendations. While the optimal range is yet to be firmly established, available evidence suggests a link between high protein intake and increased Body Mass Index (BMI), which might be driven by an increase in Fat-Free Mass Index (FFMI), as opposed to Fat Mass Index (FMI).

Sialic Acid and Sialylated Oligosaccharide Supplementation during Lactation Improves Learning and Memory in Rats.

Sialic acids (Sia) are postulated to improve cognitive abilities. This study evaluated Sia effects on rat behavior when administered in a free form as N-acetylneuraminic acid (Neu5Ac) or conjugated as 6'-sialyllactose (6'-SL). Rat milk contains Sia, which peaks at Postnatal Day 9 and drops to a minimum by Day 15. To bypass this Sia peak, a cohort of foster mothers was used to raise the experimental pups. A group of pups received a daily oral supplementation of Neu5Ac to mimic the amount naturally present in rat milk, and another group received the same molar amount of Sia as 6'-SL. The control group received water. After weaning, rats were submitted to behavioral evaluation. One year later, behavior was re-evaluated, and in vivo long-term potentiation (LTP) was performed. Brain samples were collected and analyzed at both ages. Adult rats who received Sia performed significantly better in the behavioral assessment and showed an enhanced LTP compared to controls. Within Sia groups, 6'-SL rats showed better scores in some cognitive outcomes compared to Neu5Ac rats. At weaning, an effect on polysialylated-neural cell adhesion molecule (PSA-NCAM) levels in the frontal cortex was only observed in 6'-SL fed rats. Providing Sia during lactation, especially as 6'-SL, improves memory and LTP in adult rats.

Oral supplementation of 2'-fucosyllactose during lactation improves memory and learning in rats.

Human milk oligosaccharides have been proposed to exert beneficial effects on brain development. During the last decades, most of the studies have focused on the evaluation of sialylated structures but recent experiments have also tested fucosylated oligosaccharides, i.e. 2'-fucosyllactose (2'-FL). The present study aimed to determine whether oral 2'-FL has an effect on the development of newborn brain, contributing to enhance cognitive skills later in life. Rat pups received an oral supplementation of 2'-FL (2'-FL group) or water (control group) during the lactation period. Thereafter, animals were maintained on a rodent standard diet. Rats (n=12 rats/group) were evaluated twice, at age 4-6weeks and again at age 1year, using classical behavioral tests. In vivo long-term potentiation (LTP) was also performed at the same ages (n=10 rats/group). Both groups showed similar behavior when the animals were assessed just after weaning (age 4-6weeks), although the 2'-FL group seemed to perform slightly better in Morris Water Maze. At age 1year, 2'-FL rats performed significantly better in the Novel Object Recognition and Y maze paradigms, when compared to controls. In addition, LTP was more intense and longer lasting in the rats supplemented with 2'-FL than in control animals, both in young and adult animals. Oral administration of 2'-FL exclusively during lactation enhanced cognitive abilities, not only in childhood but also in adulthood.