A modified low-protein infant formula supports adequate growth in healthy, term infants: a randomized, double-blind, equivalence trial

Low-Protein Infant Formula Enriched with Alpha-Lactalbumin during Early Infancy May Reduce Insulin Resistance at 12 Months: A Follow-Up of a Randomized Controlled Trial

High protein intake during infancy results in accelerated early weight gain and potentially later obesity. The aim of this follow-up study at 12 months was to evaluate if modified low-protein formulas fed during early infancy have long-term effects on growth and metabolism. In a double-blinded RCT, the ALFoNS study, 245 healthy-term infants received low-protein formulas with either alpha-lactalbumin-enriched whey (α-lac-EW; 1.75 g protein/100 kcal), casein glycomacropeptide-reduced whey (CGMP-RW; 1.76 g protein/100 kcal), or standard infant formula (SF; 2.2 g protein/100 kcal) between 2 and 6 months of age. Breastfed (BF) infants served as a reference. At 12 months, anthropometrics and dietary intake were assessed, and serum was analyzed for insulin, C-peptide, and insulin-like growth factor 1 (IGF-1). Weight gain between 6 and 12 months and BMI at 12 months were higher in the SF than in the BF infants (p = 0.019; p < 0.001, respectively), but were not significantly different between the low-protein formula groups and the BF group. S-insulin and C-peptide were higher in the SF than in the BF group (p < 0.001; p = 0.003, respectively), but more alike in the low-protein formula groups and the BF group. Serum IGF-1 at 12 months was similar in all study groups. Conclusion: Feeding modified low-protein formula during early infancy seems to reduce insulin resistance, resulting in more similar growth, serum insulin, and C-peptide concentrations to BF infants at 6-months post intervention. Feeding modified low-protein formula during early infancy results in more similar growth, serum insulin, and C-peptide concentrations to BF infants 6-months post intervention, probably due to reduced insulin resistance in the low-protein groups.

Higher versus lower protein intake in formula-fed term infants

BACKGROUND

Many infants are fed infant formulas to promote growth. Some formulas have a high protein content (≥ 2.5 g per 100 kcal) to accelerate weight gain during the first year of life. The risk-benefit balance of these formulas is unclear.

OBJECTIVES

To evaluate the benefits and harms of higher protein intake versus lower protein intake in healthy, formula-fed term infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, OpenGrey, clinical trial registries, and conference proceedings in October 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of healthy formula-fed infants (those fed only formula and those given formula as a complementary food). We included infants of any sex or ethnicity who were fed infant formula for at least three consecutive months at any time from birth. We excluded quasi-randomized trials, observational studies, and infants with congenital malformations or serious underlying diseases. We defined high protein content as 2.5 g or more per 100 kcal, and low protein content as less than 1.8 g per 100 kcal (for exclusive formula feeding) or less than 1.7 g per 100 kcal (for complementary formula feeding).

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed the risk of bias and extracted data from trials, and a fifth review author resolved discrepancies. We performed random-effects meta-analyses, calculating risk ratios (RRs) or Peto odds ratios (Peto ORs) with 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) with 95% CIs for continuous outcomes. We used the GRADE approach to evaluate the certainty of the evidence.

MAIN RESULTS

We included 11 RCTs (1185 infants) conducted in high-income countries. Seven trials (1629 infants) compared high-protein formula against standard-protein formula, and four trials (256 infants) compared standard-protein formula against low-protein formula. The longest follow-up was 11 years. High-protein formula versus standard-protein formula We found very low-certainty evidence that feeding healthy term infants high-protein formula compared to standard-protein formula has little or no effect on underweight (MD in weight-for-age z-score 0.05 SDs, 95% CI -0.09 to 0.19; P = 0.51, I2 = 61%; 7 studies, 1629 participants), stunting (MD in height-for-age z-score 0.15 SDs, 95% CI -0.05 to 0.35; P = 0.14, I2 = 73%; 7 studies, 1629 participants), and wasting (MD in weight-for-height z-score -0.12 SDs, 95% CI -0.31 to 0.07; P = 0.20, I2 = 94%; 7 studies, 1629 participants) in the first year of life. We found very low-certainty evidence that feeding healthy infants high-protein formula compared to standard-protein formula has little or no effect on the occurrence of overweight (RR 1.26, 95% CI 0.63 to 2.51; P = 0.51; 1 study, 1090 participants) or obesity (RR 1.96, 95% CI 0.59 to 6.48; P = 0.27; 1 study, 1090 participants) at five years of follow-up. No studies reported all-cause mortality. Feeding healthy infants high-protein formula compared to standard-protein formula may have little or no effect on the occurrence of adverse events such as diarrhea, vomiting, or milk hypersensitivity (RR 0.93, 95% CI 0.76 to 1.13; P = 0.44, I2 = 0%; 4 studies, 445 participants; low-certainty evidence) in the first year of life. Standard-protein formula versus low-protein formula We found very low-certainty evidence that feeding healthy infants standard-protein formula compared to low-protein formula has little or no effect on underweight (MD in weight-for-age z-score 0.0, 95% CI -0.43 to 0.43; P = 0.99, I2 = 81%; 4 studies, 256 participants), stunting (MD in height-for-age z-score -0.01, 95% CI -0.36 to 0.35; P = 0.96, I2 = 73%; 4 studies, 256 participants), and wasting (MD in weight-for-height z-score 0.13, 95% CI -0.29 to 0.56; P = 0.54, I2 = 95%; 4 studies, 256 participants) in the first year of life. No studies reported overweight, obesity, or all-cause mortality. Feeding healthy infants standard-protein formula compared to low-protein formula may have little or no effect on the occurrence of adverse events such as diarrhea, vomiting, or milk hypersensitivity (Peto OR 1.55, 95% CI 0.70 to 3.40; P = 0.28, I2 = 0%; 2 studies, 206 participants; low-certainty evidence) in the first four months of life.

AUTHORS' CONCLUSIONS

We are unsure if feeding healthy infants high-protein formula compared to standard-protein formula has an effect on undernutrition, overweight, or obesity. There may be little or no difference in the risk of adverse effects between infants fed with high-protein formula versus those fed with standard-protein formula. We are unsure if feeding healthy infants standard-protein formula compared to low-protein formula has any effect on undernutrition. There may be little or no difference in the risk of adverse effects between infants fed with standard-protein formula versus those fed with low-protein formula. The findings of six ongoing studies and two studies awaiting classification studies may change the conclusions of this review.

Infant body composition: A comprehensive overview of assessment techniques, nutrition factors, and health outcomes

Body composition assessment is a valuable tool for clinical assessment and research that has implications for long-term health. Unlike traditional measurements such as anthropometrics or body mass index, body composition assessments provide more accurate measures of body fatness and lean mass. Moreover, depending on the technique, they can offer insight into regional body composition, bone mineral density, and brown adipose tissue. Various methods of body composition assessment exist, including air displacement plethysmography, dual-energy x-ray absorptiometry, bioelectrical impedance, magnetic resonance imaging, D3 creatine, ultrasound, and skinfold thickness, each with its own strengths and limitations. In infants, several feeding practices and nutrition factors are associated with body composition outcomes, such as breast milk vs formula feeding, protein intake, breast milk composition, and postdischarge formulas for preterm infants. Longitudinal studies suggest that body composition in infancy predicts later body composition, obesity, and other cardiometabolic outcomes in childhood, making it a useful early marker of cardiometabolic health in both term and preterm infants. Emerging evidence also suggests that body composition during infancy predicts neurodevelopmental outcomes, particularly in preterm infants at high risk of neurodevelopmental impairment. The purpose of this narrative review is to provide clinicians and researchers with a comprehensive overview of body composition assessment techniques, summarize the links between specific nutrition practices and body composition in infancy, and describe the neurodevelopmental and cardiometabolic outcomes associated with body composition patterns in term and preterm infants.

Safety and Suitability of an Infant Formula Manufactured from Extensively Hydrolysed Protein in Healthy Term Infants

We aimed to demonstrate that healthy term infants experience noninferior growth with infant formula manufactured from extensively hydrolysed whey protein (eHF) compared to intact cow's milk protein (control formula, CF). This prospective, randomised, double-blind, parallel-group, controlled, multicentre trial included healthy term infants who were exclusively formula-fed. Infants ≤ 25 days of age received eHF or CF for at least three months up to 120 days of age, with a follow-up until 180 days of age. A reference group included exclusively breastfed infants (BF). Of 318 infants randomised, 297 (148 CF, 149 eHF) completed the study per protocol. Weight gain up to 120 days of age was noninferior (margin -3.0 g/day) in eHF (28.95 (95% CI: 27.21; 30.68) g/day) compared to CF (28.85 (95% CI: 27.10; 30.61) g/day) with a difference in means of 0.09 g/day and a lower limit of the one-sided 97.5% CI of -0.86 g/day (p < 0.0001 for noninferiority testing). Weight gain remained comparable during follow-up. Further anthropometric parameters did not differ between the infant formula groups throughout the study. Growth was comparable in BF. No relevant safety issues were observed. To conclude, eHF meets infant requirements for adequate growth during the first six months of life and can be considered safe and suitable.

Associations between Maternal Diet, Human Milk Macronutrients, and Breast-Fed Infant Growth during the First Month of Life in the SMILE Iwamizawa in Japan

Maternal diet may affect human milk macronutrients, but it remains to be elucidated whether this is also influential in infant growth. This study aimed to examine (1) how maternal diet influences human milk macronutrients, and (2) to what extent the variation in milk macronutrients affects infant growth during the first month of life. In 71 Japanese lactating women, maternal dietary information was collected from the brief-type self-administered diet history questionnaire, and anthropometry of mother-infant dyads was collected from medical records. Macronutrients in milk were analyzed by a Human Milk Analyzer. Maternal retinol intake was associated with the carbohydrate content in human milk at 1-month postpartum (standardized β coefficient: 0.287; p = 0.038). Moreover, the energy content in human milk was associated with an increase in the weight standard deviation score based on the WHO growth standard at 1 month of age (standardized β coefficient: 0.399; p = 0.046). Nevertheless, the milk macronutrient was not associated with the risk of infant growth abnormalities. In conclusion, a part of the maternal diet impacts macronutrient contents in human milk, but milk macronutrients have a limited effect on infant growth only within the normal growth curve during the first month of life.

World Trends in Infant Formulas Composition Enhancement

This article provides the overview of the major strategies for infant formulas composition enhancement via modern technologies and trends in minimizing technology-related loads on the environment. Potential modifications of quantitative and qualitative characteristics of milk formulas nutrients have been determined. We also covered product contents changing over age, as well as the perspectives of using animal milk in formulas. The relevance of adding biologically active substances and living microorganisms (probiotics), their safety, and efficacy are discussed.

Effects of a Novel High-Quality Protein Infant Formula on Energetic Efficiency and Tolerance: A Randomized Trial

OBJECTIVES

Protein overfeeding in infants can have negative effects, such as diabetes and childhood obesity; key to reducing protein intake from formula is improving protein quality. The impact of a new infant formula [study formula (SF)] containing alpha-lactalbumin, lactoferrin, partially hydrolyzed whey, and whole milk on growth and tolerance compared to a commercial formula (CF) and a human milk reference arm was evaluated.

METHODS

This randomized, double-blind trial included healthy, singleton, term infants, enrollment age ≤14 days. Primary outcome was mean daily weight gain. Secondary outcomes were anthropometrics, formula intake, serum amino acids, adverse events, gastrointestinal characteristics, and general disposition.

RESULTS

Non-inferiority was demonstrated. There were no differences between the formula groups for z scores over time. Formula intake [-0.33 oz/kg/day, 95% confidence interval (CI): -0.66 to -0.01, P = 0.05] and mean protein intake (-0.13 g/kg/day, 95% CI: -0.26 to 0.00, P = 0.05) were lower in the SF infants, with higher serum essential amino acid concentrations (including tryptophan) compared to the CF infants. Energetic efficiency was 14.0% (95% CI: 8.3%, 19.7%), 13.0% (95% CI: 6.0%, 20.0%), and 18.1% (95% CI: 9.4%, 26.8%) higher for weight, length, and head circumference, respectively, in SF infants compared to the CF infants. SF infants had significantly fewer spit-ups and softer stool consistency than CF infants.

CONCLUSIONS

The SF resulted in improved parent-reported gastrointestinal tolerance and more efficient growth with less daily formula and protein intake supporting that this novel formula may potentially reduce the metabolic burden of protein overfeeding associated with infant formula.

Low-Protein Infant Formula and Obesity Risk

Infant formulas have been designed to mimic human milk for infants who cannot be breastfed. The overall goal is to establish similar functional outcomes to assure optimal growth, development, maturation of the immune system, and programming of the metabolic system. However, after decades of improving infant formula, growth patterns and body composition development are still different in formula-fed infants compared to breastfed infants, which could contribute to an increased risk of obesity among formula-fed infants. It has been hypothesized that the lower protein concentration of breast milk compared to infant formula influences infants’ growth and body composition. Thus, several trials in formula-fed infants with different protein intake levels have been performed to test this hypothesis. In this review, we discuss the current evidence on low-protein infant formula and obesity risk, including future perspectives and implications.

The Association of Formula Protein Content and Growth in Early Infancy: A Systematic Review and Meta-Analysis

This systematic review aimed to examine differences in growth outcomes between breastfed infants and infants fed with formula with different protein/energy ratios during the first six months of life. We conducted a systematic review in the PubMed, Web of Science, and Springer databases. Twenty clinical trials qualified for inclusion. We extracted data about the growth outcomes of infants who were exclusive breastfed or exclusively infant formula fed in the first six months and used a meta-analysis to pool the finding data. We categorized study formulas into four groups according to their protein content: <1.8, 1.8−2.0, 2.1−2.2, and >2.2 g/100 kcal. In the first month of life, growth was not different between formula- and breastfed infants. During 2−3 months of life, growth was faster in infants who consumed formulas with protein contents higher than 2.0 g/100 kcal. After 3 months, formula-fed infants grew faster than breastfed infants. Our meta-analysis indicated that the growth outcomes of infants fed with infant formula with a relatively low protein/energy ratios, compared with that a relatively high protein/energy ratio, were close to those of breastfed infants.

Childhood obesity prevention: what can be achieved?

PURPOSE OF REVIEW

Childhood obesity is a pandemic generating an enormous individual and socioeconomic burden worldwide. This narrative review summarizes recent evidence on successful and recommended prevention strategies according to age groups and different levels of interventions.

RECENT FINDINGS

Effective prevention of childhood obesity is feasible and most successful early in life up to preschool age, and it should include a multicomponent approach, integrating individuals, family and society. Trials that improve nutrition and/or enhance physical activity are the cornerstones of childhood obesity prevention on an individual level. However, their efficacy is determined by the combination of interventions for the target age group. Further, improving family support and sleep, as well as reducing screen time, lead to favourable results. Many research gaps remain, including a lack of effective interventions for high-risk groups.

SUMMARY

As a multifactorial condition, childhood obesity requires a multicomponent approach. Interventions should be developmental stage-specific and adjusted to the setting. Current research gaps need to be targeted by future trials, with a special focus on the benefit of the most vulnerable groups. From a systems response perspective, a paradigm shift from interventions focusing on the individual to approaches that target society as a whole is warranted.

Infant Formula with Added Bovine Milk Fat Globule Membrane and Modified Iron Supports Growth and Normal Iron Status at One Year of Age: A Randomized Controlled Trial

Inclusion of bovine-derived milk fat globule membrane (bMFGM) or bMFGM components in infant formulas (IFs) may support healthy brain development. This double-blind, prospective trial evaluated growth, tolerance, and iron status in infants receiving added bMFGM and modified protein, iron, and arachidonic acid (ARA) concentrations in IF. Healthy term infants were randomized to: control (marketed, routine cow's milk-based IF/100 kcal: 2.1 g protein, 1.8 mg iron, 34 mg ARA) or INV-MFGM (investigational cow's milk-based IF/100 kcal: 1.9 g protein, 1.2 mg iron, 25 mg ARA and whey protein-lipid concentrate, 5 g/L (source of bMFGM)). Anthropometrics, stool characteristics, fussiness, and gassiness through day 365 and blood markers of iron status at day 365 were evaluated. The primary outcome was rate of weight gain from 14-120 days of age. Of 373 infants enrolled (control: 191, INV-MFGM: 182), 275 completed the study (control: 141; INV-MFGM: 134). No group differences in growth rate (g/day) from day 14-120 or study discontinuation were detected. Few group differences in growth or parent-reported fussiness, gassiness, or stool characteristics were detected. No group differences were detected in hemoglobin, hematocrit, or incidence of anemia. In healthy term infants, bMFGM and modified protein, iron, and ARA concentrations in a cow's milk-based IF were well-tolerated, associated with adequate growth throughout the first year of life, and supported normal iron status at one year of age.

Breastfeeding and risk of overweight in childhood and beyond: a systematic review with emphasis on sibling-pair and intervention studies

BACKGROUND

Breastfeeding is associated with a lower risk of subsequent overweight or obesity, but it is uncertain whether this is a causal relation because most studies have not adequately reduced risk of bias due to confounding.

OBJECTIVES

The aim of this review was to examine whether 1) ever compared with never consuming human milk and 2) different durations of human milk consumption among infants fed human milk are related to later risk of overweight or obesity, with emphasis on sibling-pair and intervention studies.

METHODS

The 2020 Dietary Guidelines Advisory Committee, together with the Nutrition Evidence Systematic Review team, conducted a systematic review of articles relevant to healthy full-term infants in countries with a high or very high level of human development. We searched PubMed, Embase, Cochrane, and CINAHL; dual-screened the results using predetermined criteria; extracted data from and assessed the risk of bias for each included study; qualitatively synthesized the evidence; developed conclusion statements; and graded the strength of the evidence.

RESULTS

The review included 42 articles, including 6 cohorts with sibling-pair analyses and 1 randomized controlled trial of a breastfeeding promotion intervention. Moderate evidence suggested that ever, compared with never, consuming human milk is associated with a lower risk of overweight and obesity at ages 2 y and older, particularly if the duration of human milk consumption is >6 mo. However, residual confounding cannot be ruled out. Evidence was insufficient to determine the relation between the duration of any human milk consumption, among infants fed human milk, and overweight and/or obesity at age 2 y and older.

CONCLUSIONS

Further research, using strong study designs, is needed to disentangle the complex relation between infant feeding practices and the risk of subsequent overweight or obesity, as well as the biological and behavioral mechanisms if the relation is causal.

Early-Life Metabolic and Hormonal Markers in Blood and Growth until Age 2 Years: Results from a Randomized Controlled Trial in Healthy Infants Fed a Modified Low-Protein Infant Formula

Background: High protein intake in early life is associated with an increased risk of childhood obesity. Dietary protein intake may be a key mechanistic modulator through alterations in endocrine and metabolic responses. Objective: We aimed to determine the impact of different protein intake of infants on blood metabolic and hormonal markers at the age of four months. We further aimed to investigate the association between these markers and anthropometric parameters and body composition until the age of two years. Design: Term infants received a modified low-protein formula (mLP) (1.7 g protein/100 kcal) or a specifically designed control formula (CTRL) (2.1 g protein/100 kcal) until 6 months of age in a double blinded RCT. The outcomes were compared with a breast-fed (BF) group. Glucose, insulin, leptin, IGF-1, IGF-BP1, -BP2, and -BP3 levels were measured at the age of 4 months. Anthropometric parameters and body composition were assessed until the age of 2 years. Groups were compared using linear regression analysis. Results: No significant differences were observed in any of the blood parameters between the formula groups (n = 53 mLP; n = 44 CTRL) despite a significant difference in protein intake. Insulin and HOMA-IR were higher in both formula groups compared to the BF group (n = 36) (p < 0.001). IGF-BP1 was lower in both formula groups compared to the BF group (p < 0.01). We found a lower IGF-BP2 level in the CTRL group compared to the BF group (p < 0.01) and a higher IGF-BP3 level in the mLP group compared to the BF group (p = 0.03). There were no significant differences in glucose, leptin, and IGF-1 between the three feeding groups. We found specific associations of all early-life metabolic and hormonal blood parameters with long-term growth and body composition except for IGF-1. Conclusions: Reducing protein intake by 20% did not result in a different metabolic profile in formula-fed infants at 4 months of age. Formula-fed infants had a lower insulin sensitivity compared to breast-fed infants. We found associations between all metabolic and hormonal markers (except for IGF-1) determined at age 4 months and growth and body composition up to two years of age.

Methods to Assess Fat Mass in Infants and Young Children: A Comparative Study Using Skinfold Thickness and Air-Displacement Plethysmography

Background: Traditionally, fat mass is estimated using anthropometric models. Air-displacement plethysmography (ADP) is a relatively new technique for determining fat mass. There is limited information on the agreement between these methods in infants and young children. Therefore we aimed to longitudinally compare fat mass percentage values predicted from skinfold thicknesses (SFTs) and ADP in healthy infants and young children. Methods: Anthropometry and body composition were determined at the ages of 1, 4, and 6 months and 2 years. We quantified the agreement between the two methods using the Bland–Altman procedure, linear mixed-model analysis, and intra-class correlation coefficients (ICC). Results: During the first 6 months of life, fat mass% predicted with SFT was significantly different from that measured with ADP in healthy, term-born infants (n = 245). ICCs ranged from 0.33 (at 2 years of age) and 0.47 (at 4 months of age). Although the mean difference (bias) between the methods was low, the Bland–Altman plots showed proportional differences at all ages with wide limits of agreement. Conclusions: There is poor agreement between ADP and SFTs for estimating fat mass in infancy or early childhood. The amount of body fat was found to influence the agreement between the methods.

Innovations in Infant Feeding: Future Challenges and Opportunities in Obesity and Cardiometabolic Disease

The field of nutrition in early life, as an effective tool to prevent and treat chronic diseases, has attracted a large amount of interest over recent years. The vital roles of food products and nutrients on the body’s molecular mechanisms have been demonstrated. The knowledge of the mechanisms and the possibility of controlling them via what we eat has opened up the field of precision nutrition, which aims to set dietary strategies in order to improve health with the greatest effectiveness. However, this objective is achieved only if the genetic profile of individuals and their living conditions are also considered. The relevance of this topic is strengthened considering the importance of nutrition during childhood and the impact on the development of obesity. In fact, the prevalence of global childhood obesity has increased substantially from 1990 and has now reached epidemic proportions. The current narrative review presents recent research on precision nutrition and its role on the prevention and treatment of obesity during pediatric years, a novel and promising area of research.

An Infant Formula with Partially Hydrolyzed Whey Protein Supports Adequate Growth and Is Safe and Well-Tolerated in Healthy, Term Infants: A Randomized, Double-Blind, Equivalence Trial

The current study evaluates the safety and tolerance of a partially hydrolyzed whey protein-based infant formula (PHF) versus an in intact cow’s milk protein formula (IPF). Breastfed infants were included as a reference group. In a multi-country, multicenter, randomized, double-blinded, controlled clinical trial, infants whose mothers intended to fully formula feed were randomized to PHF (n = 134) or IPF (n = 134) from ≤14 days to 17 weeks of age. The equivalence analysis of weight gain per day within margins of +/−3 g/d (primary outcome), the recorded adverse events, growth and gastro-intestinal tolerance parameters were considered for the safety evaluation. Equivalence of weight gain per day from enrolment until 17 weeks of age was demonstrated in the PHF group compared to the IPF group (difference in means −1.2 g/d; 90% CI (−2.42; 0.02)), with estimated means (SE) of 30.2 (0.5) g/d and 31.4 (0.5) g/d, respectively. No significant differences in growth outcomes, the number, severity or type of (serious) adverse events and tolerance outcomes, were observed between the two formula groups. A partially hydrolyzed whey protein-based infant formula supports adequate infant growth, with a daily weight gain equivalent to a standard intact protein-based formula; it is also safe for use and well-tolerated in healthy term infants.