Association of Protein Intake during the Second Year of Life with Weight Gain-Related Outcomes in Childhood: A Systematic Review

Association between protein-to-energy ratio and overweight/obesity in children and adolescents in the United States: a cross-sectional study based on NHANES

Background

The dietary protein proportion may be crucial in triggering overweight and obesity among children and adolescents.

Methods

Cross-sectional data from 4,336 children and adolescents who participated in the National Health and Nutrition Survey (NHANES) between 2011 and March 2020 were analyzed. Multivariate logistic regression was used to calculate odds ratio (OR) and 95% confidence interval (CI). Restricted cubic splines assessed the nonlinear relationships between dietary protein intake and the prevalence of overweight and obesity.

Results

Adjusted logistic regression models showed that each 1% increase in dietary protein proportion was associated with a 4% higher risk of overweight and obesity (OR = 1.04, 95% CI: 1.01-1.07). A nonlinear relationship was noted in children aged 6-11 years (P < 0.05), as demonstrated by restricted cubic spline analysis. After dividing dietary protein intake into quartiles, the highest quartile had an adjusted OR of 2.07 (95% CI: 1.35, 3.16, P = 0.001) compared to the lowest, among children aged 6-11 years.

Conclusion

Dietary protein intake is positively linked to overweight and obesity in American children, irrespective of individual characteristics and total energy consumption.

A repeated cross-sectional analysis of the Icelandic baby food market surveyed in 2016, 2019 and 2021

World Health Organisation (WHO) has stated that countries need to know their local commercial baby food (CBF) market. Data from other countries suggest rapid changes in CBF options, highlighting the need for repeated analysis. In that context, this repeated cross-sectional study analysed the options and nutrient quality of different CBF types available in Iceland in years 2016, 2019 and 2021. Data was gathered on formulas, porridge flours, foods in jars and pouches, finger-foods, other CBF. They were classified into 26 subgroups based on ingredients and taste (sweet/savoury). Minimum consumer age as suggested by the manufacturers and nutritional content were registered. In each data-collection, 250-275 products were available. Over a third of products (37%-44%) were in pouches. Availability of products intended for 4-11-month-old infants decreased, driven largely by a 65% decrease in availability of food in jars (sweet/savoury) between 2016 and 2021. Availability of products intended from 12+ months or without age-labels increased, driven largely by quadrupling of finger-foods (predominantly sweet) between 2016 and 2021. The overall percentage of products classified as sweet increased from 65% (2016) to 73% (2019) and 77% (2021). Some finger-foods had high sugar content (up to 72 g/100 g), partly from fruit concentrate or sugar/syrup. Like other countries, the Icelandic CBF market has moved towards less availability of food intended in the first year and more availability of sweet finger-foods for an expanded consumer age. As sugar is added to some CBF, stronger regulations on promotion of foods for young consumers and updated recommendations for parents/caregivers may be needed.

Dietary Intake and Body Mass Index Influence the Risk of Islet Autoimmunity in Genetically At-Risk Children: A Mediation Analysis Using the TEDDY Cohort

Background/Objective

Growth and obesity have been associated with increased risk of islet autoimmunity (IA) and progression to type 1 diabetes. We aimed to estimate the effect of energy-yielding macronutrient intake on the development of IA through BMI.

Research Design and Methods

Genetically at-risk children (n = 5,084) in Finland, Germany, Sweden, and the USA, who were autoantibody negative at 2 years of age, were followed to the age of 8 years, with anthropometric measurements and 3-day food records collected biannually. Of these, 495 (9.7%) children developed IA. Mediation analysis for time-varying covariates (BMI z-score) and exposure (energy intake) was conducted. Cox proportional hazard method was used in sensitivity analysis.

Results

We found an indirect effect of total energy intake (estimates: indirect effect 0.13 [0.05, 0.21]) and energy from protein (estimates: indirect effect 0.06 [0.02, 0.11]), fat (estimates: indirect effect 0.03 [0.01, 0.05]), and carbohydrates (estimates: indirect effect 0.02 [0.00, 0.04]) (kcal/day) on the development of IA. A direct effect was found for protein, expressed both as kcal/day (estimates: direct effect 1.09 [0.35, 1.56]) and energy percentage (estimates: direct effect 72.8 [3.0, 98.0]) and the development of GAD autoantibodies (GADA). In the sensitivity analysis, energy from protein (kcal/day) was associated with increased risk for GADA, hazard ratio 1.24 (95% CI: 1.09, 1.53), p = 0.042.

Conclusions

This study confirms that higher total energy intake is associated with higher BMI, which leads to higher risk of the development of IA. A diet with larger proportion of energy from protein has a direct effect on the development of GADA.

Impact of complementary feeding on obesity risk

PURPOSE OF REVIEW

To discuss recent evidence on the influence of complementary feeding (CF) timing, content and feeding methods on childhood obesity risk.

RECENT FINDINGS

The evidence-base is limited by heterogeneity, risk of bias and the predominance of observational studies. The content of the diet and feeding practices are more influential than timing for obesity risk. There is limited evidence that CF introduction before 4 months may be associated with increased risk. Intake of animal protein, particularly dairy protein, may contribute to rapid weight gain; protein from infant/follow-on formula shows the most robust association with later obesity risk. Evidence linking sugar intake to obesity risk is limited, but intake should be as low as possible given there is no nutritional requirement. Responsive feeding (RF) practices may promote appropriate infant growth and reduce risk. The effect of baby-led weaning (BLW) is inconclusive.

SUMMARY

Recent evidence supports current recommendations to avoid high protein intakes, especially from infant/follow-on formula, for infants in high income countries; and to promote RF practices for all infants. Studies in low- and middle-income countries are required to define optimal CF practices given increasing rates of child obesity alongside double-burden malnutrition.

Correlation of maternal dietary intake with breast milk composition and infant growth

Background: Maternal dietary intake during the period of lactation has an impact on infants growth. Macronutrients in breast milk are affected by several factors such as maternal dietary intake and maternal nutritional status. This study aims to prove the association between maternal protein and fat intake with the composition of breast milk and growth of infants (age 0-6 months). Methods: Prospective study was conducted for 6 months in 41 mother-infant pairs who were exclusively breastfed, and visited to hospitals or health centres. The mothers age is <40 years old with normal and single pregnancy. The breast milk was collected and analyzed using Human Milk Analyzer. Results: There was a negative correlation between maternal protein intake and breast milk composition at 3 months old infants (p = 0.042), between fat intake with HAZ score at 2 weeks (p = 0.048), and between protein intake with HAZ score at 3 months (p = 0.049). Finally, there was a significant increase in WAZ and HAZ score in all sample groups. Although the maternal protein intake of our subjects were only at 83% of Indonesian's RDA average, the protein composition of breast milk and the growth of the infants was sufficient. Conclusion: There is correlation between maternal dietary intake with the composition of breastmilk and infant growth. Even though the calories and protein intake of the mother is lower than the RDA, the breast milk is still sufficient for the growth of infants aged 0-6 months who are exclusively breastfed.

Non-Dairy Animal Protein Consumption Is Positively Associated with Overweight and Obesity in Israeli Adolescents

Protein consumption apparently plays a role in weight control. This cross-sectional study examined the association of protein consumption in Israeli adolescents with overweight/obesity. 7th−12th grade students participating in a national school-based survey (2015−2016) completed self-administered questionnaires, including a food frequency questionnaire, and height and weight measurements (n = 3443, 48% males, 15.2 ± 1.6 years). WHO growth standards served to define weight status. Intakes of total protein and protein source were calculated. Multivariable logistic regression analyses evaluated associations with overweight/obesity (BMI z-score ≥ 1), adjusting for possible covariates. Total protein intake (median (IQR)) was 62.5 (45.5, 85.7) g/d, accounting for 12.0 (10.5, 13.6) percent of daily energy. Of participants, 31.4% were overweight/obese. In multivariable models, overweight/obesity was positively associated with incremental increases of 10 g/d in total protein intake (OR = 1.07, 95% CI: 1.02−1.12, p < 0.01), total animal protein intake (OR = 1.05, 95% CI: 1.01−1.10, p = 0.026), and non-dairy animal protein intake (OR = 1.06, 95% CI: 1.01−1.11, p = 0.029). No associations were found with plant or dairy protein intake. These associations remained when protein intake was reported as a percentage of daily energy and when overweight and obesity were analyzed individually. High daily protein intakes, principally from non-dairy animal sources, were positively associated with overweight/obesity in adolescents. Additional studies are needed to establish causality of these findings.

Protein intake in children and growth and risk of overweight or obesity: A systematic review and meta-analysis

Objectives

The aim of this study was to examine the evidence for an association between the dietary protein intake in children and the growth and risk of overweight or obesity up to 18 years of age in settings relevant for the Nordic countries.

Methods

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus up to February 26, 2021 for randomized controlled trials (RCTs) or prospective cohort studies assessing for protein intake from foods (total and from different sources) in children. The outcomes include weight, height/length, adiposity indices, and/or risk of overweight and/or obesity. The risk of bias was evaluated with instruments for each respective design (Cochrane’s Risk of Bias 2.0 and RoB-NObS). A meta-analysis of five cohort studies was performed. The evidence was classified according to the criteria of the World Cancer Research Fund.

Results

The literature search resulted in 9,132 abstracts, of which 55 papers were identified as potentially relevant. In total, 21 studies from 27 publications were included, of which five were RCTs and 16 were cohort studies. The RCTs found generally null effects of high-protein intake in infants on weight gain, nor that lower protein diets negatively affected growth. All included RCTs had some concern regarding the risk of bias and were limited by small sample sizes. Total protein intake and BMI were assessed in 12 cohorts, of which 11 found positive associations. The meta-analysis revealed a pooled effect estimate of 0.06 (95% CI 0.03, 0.1) kg/m² BMI per one E% increment in total protein (I² = 15.5). Therefore, the evidence for a positive relationship between total protein intake and BMI was considered probable. Furthermore, there was probable evidence for an association between higher intake of animal protein and increased BMI. There was limited, suggestive evidence for an effect of total protein intake and higher risk of overweight and/or obesity, while no conclusions could be made on the associations between animal vs. plant protein intake and risk of overweight and/or obesity.

Discussion

In healthy, well-nourished children of Western populations, there is probably a causal relationship between a high-protein intake in early childhood (≤ 18 months) – particularly protein of animal origin – and higher BMI later in childhood, with consistent findings across cohort studies. A lack of RCTs precluded a stronger grading of the evidence.

Protein intake pattern in non-breastfed infants and toddlers: A survey in a nationally representative sample of French children

BACKGROUND AND AIMS

Protein intake plays a key role in infants and children's growth, but high protein intake may have adverse long-term effects. Data on actual intakes in various populations are scarce. The aims of this study were (i) to assess daily protein intake (DPI) in non-breastfed infants and children aged 0.5-35 months in comparison with the population reference intake (PRI) set by the European Food Safety Authority, and to examine (ii) the various sources of this intake and their consumption patterns, and (iii) time-related changes in DPI over the last 4 decades.

METHODS

Data from the Nutri-Bébé cross-sectional survey were used to assess DPI, DPI/kg BW and the protein-energy ratio (E%) by age group. The amounts and quality of each food consumed were recorded over three non-consecutive days and validated by two face-to-face interviews.

RESULTS

Overall, this study included 1035 children. Median DPI were consistently above the PRI, reaching 4 times PRI in the older toddlers (41.4 g/d; range 15.1-64.0). Regardless of age, more than 95% of children had a DPI/kg BW above the PRI. Protein intake remained below 14 E% until 6 months of age and increased thereafter from 10% to 75% in children older than one year. Overall, DPI gradually decreased from 1981 to 2013. Milk and dairy products were the main contributors to DPI up to 2 years, while the share of other animal sources became predominant later. Plant contribution remained below 25% of DPI.

CONCLUSION

Despite a gradual decrease over the last few decades, DPI have remained well above the PRI. As the predominant contributors to these intakes are animal sources, the potential long term health consequences of such high intake deserve consideration.

CLINICAL TRIAL REGISTRY NUMBER

NCT03327415 on ClinicalTrials.gov.

Complementary Feeding and Iron Status: "The Unbearable Lightness of Being" Infants

The complementary feeding (CF) period that takes place between 6 and 24 months of age is of key importance for nutritional and developmental reasons during the transition from exclusively feeding on milk to family meals. In 2021, a multidisciplinary panel of experts from four Italian scientific pediatric societies elaborated a consensus document on CF, focusing in particular on healthy term infants. The aim was to provide healthcare providers with useful guidelines for clinical practice. Complementary feeding is also the time window when iron deficiency (ID) and iron deficiency anemia (IDA) are most prevalent. Thus, it is appropriate to address the problem of iron deficiency through nutritional interventions. Adequate iron intake during the first two years is critical since rapid growth in that period increases iron requirements per kilogram more than at any other developmental stage. Complementary foods should be introduced at around six months of age, taking into account infant iron status.

Which Milk during the Second Year of Life: A Personalized Choice for a Healthy Future?

Nutrition in early life is a crucial element to provide all essential substrates for growth. Although this statement may appear obvious, several studies have shown how the intake of micro and macronutrients in toddlers differs a lot from the recommendations of scientific societies. Protein intake often exceeds the recommended amount, while the intake of iron and zinc is frequently insufficient, as well as Vitamin D. Nutritional errors in the first years of life can negatively impact the health of the child in the long term. To date, no clear evidence on which milk is suggested during the second year of life is yet to be established. In this study, we compare the nutrient profiles of cow’s milk and specific formulas as well as nutritional risks in toddlers linked to growth and childhood obesity development. The purpose of this review is to resume the latest clinical studies on toddlers fed with cow’s milk or young children formula (YCF), and the potential risks or benefits in the short and long term.

Acute Metabolic Response in Adults to Toddler Milk Formulas with Alternating Higher and Lower Protein and Fat Contents, a Randomized Cross-Over Trial

Protein intake in early life influences metabolism, weight gain, and later obesity risk. As such, a better understanding of the effects of protein intake on the postprandial metabolism and its dynamics over time may elucidate underlying mechanisms. In a randomized crossover study, we observed fasted adults who consumed two isocaloric toddler milk formulas concentrated as meals of 480 kcal with 67 g of carbohydrates 30 g (HP) or 7 g (LP) protein, and 10 g or 20 g fat, respectively. Anthropometry and body plethysmography were assessed, and blood samples collected at baseline and over five hours. Time-specific concentrations, areas under concentration curves (AUC), and maximum values of metabolites were compared by paired t-tests to examine the effects of protein content of toddler milks on postprandial plasma concentrations of insulin, glucose, branched-chain amino acids (BCAA), urea and triglycerides. Twenty-seven men and women aged 26.7 ± 5.0 years (BMI: 22.2 ± 2.5 kg/m²) (mean ± SD) participated. BCAA AUC, and Cmax values were significantly higher with HP than LP (144,765 ± 21,221 vs. 97,089 ± 14,650 µmol·min/L, p < 0.001; 656 ± 120 vs. 407 ± 66 µmol/L, p < 0.001), as were insulin AUC and Cmax values (6674 ± 3013 vs. 5600 ± 2423 µmol·min/L, p = 0.005; 71 ± 37 vs. 55 ± 28 µmol/L, p = 0.001). Higher glucose, urea, and triglyceride concentrations occurred in the late postprandial phase (≥180 min) with HP. In conclusion, we noted that higher milk protein intake induces increased postprandial BCAA concentrations for at least 5 h and led to higher initial insulin secretion. Gluconeogenesis due to an influx of amino acids and their degradation after HP meal might explain the late effects of protein intake on glucose and insulin.

Complementary Foods and Milk-Based Formulas Provide Excess Protein but Suboptimal Key Micronutrients and Essential Fatty Acids in the Intakes of Infants and Toddlers from Urban Settings in Malaysia

This study determined the intakes of complementary foods (CFs) and milk-based formulas (MFs) by a total of 119 subjects aged 6-23.9 months from urban day care centers. Dietary intakes were assessed using two-day weighed food records. Intake adequacy of energy and nutrients was compared to the Recommended Nutrient Intakes (RNI) for Malaysia. The most commonly consumed CFs were cereals (rice, noodles, bread). The subjects derived approximately half of their energy requirements (kcals) from CFs (57 ± 35%) and MFs (56 ± 31%). Protein intake was in excess of their RNI requirements, from both CFs (145 ± 72%) and MFs (133 ± 88%). Main sources of protein included meat, dairy products, and western fast food. Intake of CFs provided less than the RNI requirements for vitamin A, thiamine, riboflavin, folate, vitamin C, calcium, iron, and zinc. Neither CF nor MF intake met the Adequate Intake (AI) requirements for essential fatty acids. These findings indicate imbalances in the dietary intake of the subjects that may have adverse health implications, including increased risk of rapid weight gain from excess protein intake, and linear growth faltering and intellectual impairment from multiple micronutrient deficiencies. Interventions are needed to improve child feeding knowledge and practices among parents and child care providers.