Nutrient intake in infancy and body mass index at six years in two population-based cohorts recruited before and after revision of infant dietary recommendations

World Health Organization (WHO) guideline on the complementary feeding of infants and young children aged 6-23 months 2023: A multisociety response

The recent World Health Organization (WHO) guideline aims to provide evidence-based recommendations on complementary feeding (CF) of healthy term infants and young children 6-23 months living in low-, middle-, and high-income countries, including both breastfed and non-breastfed children. Like WHO, our organizations aim to promote optimal infant and young child nutrition and health, with a focus on promoting breastfeeding as well as appropriate and timely CF. In this paper, we share our concerns about aspects of the guideline, some of which may have the potential to cause unintended harm in infants and young children and suggest alternative or modified proposals.

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.

Lower Intake of Saturated Fatty Acids Is Associated with Improved Lipid Profile in a 6-Year-Old Nationally Representative Population

To strengthen the organization of new national dietary surveys and interventions in childhood, our aim was to study macronutrient intake and blood lipid profile at 6 years of age by comparing results from two earlier population-based cohorts. Subjects were n = 131 and n = 162 in the years 2001−2002 and 2011−2012, respectively. Three-day weighed food records were used to estimate diet and calculate nutrient intake. Total cholesterol, HDL-cholesterol and triacylglycerol were measured in serum and LDL-cholesterol was calculated. The average intake of saturated fatty acids (SFA) and trans FA was lower in 2011−2012 than 2001−2002 (13.3E% vs. 14.7E%, p < 0.001, and 0.8E% vs. 1.4E%, p < 0.001, respectively), replaced by a higher intake of unsaturated fatty acids. Total cholesterol and LDL-cholesterol were significantly lower in 2011−2012 than 2001−2002 (4.6 vs. 4.4 mmol/L, p = 0.003 and 2.8 vs. 2.5 mmol/L, p < 0.001, respectively). In a multiple linear regression model, one E% increase in SFA intake was related to a 0.03 mmol/L increase in LDL cholesterol (p = 0.04). A lower intake of saturated and trans fatty acids, replaced by unsaturated fatty acids, may have contributed to an improved lipid profile in a healthy 6-year-old population. Biological data for analysis of blood lipids are important in national dietary surveys in healthy children to monitor important health outcomes of interventions.

Protein Intake from Birth to 2 Years and Obesity Outcomes in Later Childhood and Adolescence: A Systematic Review of Prospective Cohort Studies

Emerging evidence shows an association between protein intake during infancy and later obesity risk, and that association may differ by protein sources. This systematic review summarized and evaluated prospective cohort studies assessing the long-term association of total protein intake and protein sources during infancy (from birth to 2 y) with subsequent obesity outcomes in childhood or adolescence. Literature searches were conducted in Embase, Medline, Scopus, and Web of Science. Sixteen studies that reported associations between total protein intake and/or protein intake from different sources from birth to 2 y and ≥1 obesity outcomes in childhood or adolescence from 9 cohorts were identified. Most studies (11/16) were rated as high quality. The most frequently reported association was total protein intake and BMI (up to 10 y) with 6 out of 7 cohorts showing significant positive associations. Similar associations were found for animal protein, but not for plant protein. Limited studies examined the association between protein intake (both total and sources) and body composition (body fat, fat mass, and fat-free mass) and revealed inconsistent findings. Overall, higher intakes of total and animal protein during infancy were associated with higher BMI in childhood and adolescence. Future studies investigating the contribution of protein sources in long-term obesity development are needed. This review was registered at PROSPERO as CRD42020166540.

Protein Intake, IGF-1 Concentrations, and Growth in the Second Year of Life in Children Receiving Growing Up Milk - Lite (GUMLi) or Cow's Milk (CM) Intervention

The relationship of protein intake with insulin-like growth factor 1 (IGF-1) concentrations in well-nourished children during the second year of life is poorly understood. The aim of this study was to explore the effect of a reduced-protein Growing Up Milk Lite (GUMLi) or unfortified cow's milk (CM) on protein intake, growth, and plasma IGF-1 at 2 y. An exploratory analysis of a sub-sample of Auckland-based children (n = 79) in the GUMLi trial (a double-blind, randomised control trial, N = 160) completed in Auckland and Brisbane (2015-2017) was conducted. One-year old children were randomised to receive a reduced-protein GUMLi (1.7 g protein/100 mL) or a non-fortified CM (3.1 g protein/100 mL) for 12 months. Blood sampling and anthropometric measurements were made at 1 and 2 y. Diet was assessed using a validated food frequency questionnaire. Total protein intake (g/d) from all cow's milk sources was 4.6 g (95% CI: -6.7, -2.4; p < 0.005) lower in the GUMLi group after 12 months of the intervention, with a significant group-by-time interaction (p = 0.005). Length-for-age (LAZ) and weight-for-length (WLZ) z-scores did not differ between groups, however, mean body fat % (BF%) was 3.2% (95%CI: -6.2, -0.3; p = 0.032) lower in the GUMLi group at 2 y. There was no difference between the intervention groups in relation to IGF-1 and IGF-BP3 (p = 0.894 and 0.698, respectively), with no group-by-sex interaction. After combining the groups, IGF-1 concentration at 2 y was positively correlated with parameters of growth (all p < 0.05), total cow's milk intake (p = 0.032) after adjusting for sex, breastfeeding status, and gestation. Randomisation to a reduced protein GUMLi resulted in small reduction in %BF and lower total protein intakes but had no effect on growth. Plasma IGF-1 concentrations were independently associated with total protein intake from cow's milk at 2 y, highlighting a potential area of the diet to target when designing future protein-related nutrition interventions. Clinical Trial Registration: Australian New Zealand Clinical Trials Registry number: ACTRN12614000918628. Date registered: 27/08/2014.

Infant Feeding, Vitamin D and IgE Sensitization to Food Allergens at 6 Years in a Longitudinal Icelandic Cohort

Nordic Nutrition Recommendations (NNR) recommend exclusive breastfeeding until 6 months, partial breastfeeding until 1 year or longer and irrespective of breastfeeding, avoiding solid foods before 4 months. Strong evidence was found for benefits of breastfeeding regarding growth and infections but limited/inconclusive evidence regarding atopic disease and asthma. Vitamin D is of special interest in the Nordic diet. The aim of this prospective study was to compare infant feeding and vitamin D between immunoglobulin E (IgE) sensitized (n = 14) and non-sensitized (n = 130) children at 6 years. Information on diet and vitamin D supplement use were collected with dietary recall (<5 months), 1-d food records (5 and 6 months) and 3-d weighed food records (12 months and 6 years). Serum-specific IgE-antibodies against milk, egg, cod, wheat, soy and peanut (cut-off specific IgE ≥ 0.35 kUA/L) were measured at 6 years and serum 25-hydroxyvitamin D at 12 months and 6 years. At 4 months, 57% of IgE sensitized vs. 23% of non-sensitized children (p < 0.01) had received solid food. At 12 months, IgE sensitized children had a lower intake of vitamin D (median (25th, 75th percentiles): 3.9 μg/d (3.2, 7.2) vs. 8.1 μg/d (4.4, 12.3), p = 0.03) and at 6 years, fewer used vitamin D supplements regularly (23% vs. 56%, p = 0.03). Introduction of solid foods prior to 4 months increased the odds of IgE-sensitization, OR = 4.9 (95%, CI = 1.4–16.6) and vitamin D supplement at 6 years decreased the odds of IgE-sensitization, OR = 0.2 (95%, CI = 0.1–0.98), adjusting for maternal smoking. These observations support the NNR in their recommendation against introducing complementary solid foods before the age of 4 months. Furthermore, they support encouraging vitamin D intake for young children at northern latitudes.

Protein-Reduced Complementary Foods Based on Nordic Ingredients Combined with Systematic Introduction of Taste Portions Increase Intake of Fruits and Vegetables in 9 Month Old Infants: A Randomised Controlled Trial

Abstract: Fruits and vegetables are healthy foods but under-consumed among infants and children. Approaches to increase their intake are urgently needed. This study investigated the effects of a systematic introduction of taste portions and a novel protein-reduced complementary diet based on Nordic foods on fruit and vegetable intake, growth and iron status to 9 months of age. Healthy, term infants (n = 250) were recruited and randomly allocated to either a Nordic diet group (NG) or a conventional diet group (CG). Infants were solely breast- or formula-fed at study start. From 4 to 6 months of age, the NG followed a systematic taste portions schedule consisting of home-made purées of Nordic produce for 24 days. Subsequently, the NG was supplied with baby food products and recipes of homemade baby foods based on Nordic ingredients but with reduced protein content compared to the CG. The CG was advised to follow current Swedish recommendations on complementary foods. A total of 232 participants (93%) completed the study. The NG had significantly higher intake of fruits and vegetables than the CG at 9 months of age; 225 ± 109 g/day vs. 156 ± 77 g/day (p < 0.001), respectively. Energy intake was similar, but protein intake was significantly lower in the NG (-26%, p < 0.001) compared to the CG. This lower protein intake was compensated for by higher intake of carbohydrate from fruits and vegetables. No significant group differences in growth or iron status were observed. The intervention resulted in significantly higher consumption of fruits and vegetables in infants introduced to complementary foods based on Nordic ingredients.

Longitudinal association of dietary protein intake in infancy and adiposity throughout childhood

BACKGROUND & AIMS

Protein intake in infancy promotes growth, but excessive intake may lead to adiposity in children. However, whether this increased adiposity persists throughout childhood and is independent of diet in later life remains unclear. Therefore, we studied the associations of total protein intake and protein from different sources at age 1 year with repeatedly measured growth and body composition up to age 10 years. Additionally, we examined whether these associations are independent of protein intake and overall diet quality at age 8 years.

METHODS

We included 3573 children from the Generation R study, a population-based prospective cohort in the Netherlands. Dietary intakes were assessed with food-frequency questionnaires at ages 1 and 8 years and macronutrient intakes were expressed as energy percentages (E%). Height and weight were measured at eight time points between ages 1 and 10 years. Fat and fat-free masses were measured at ages 6 and 10 years with dual-energy X-ray-absorptiometry. We calculated body mass index (BMI), fat mass index (FMI) and fat-free mass index (FFMI). Outcomes were standardized for sex and age and expressed as standard deviation scores (SDS). Associations of protein intake with growth and body composition trajectories were examined with multivariable linear mixed models.

RESULTS

After adjustment for confounders, 5E% additional protein intake at age 1 year was associated with a 0.10 SDS higher weight (95% CI 0.04, 0.16), 0.10 SDS higher BMI (95% CI 0.04, 0.16), and 0.07 SDS higher FMI (95% CI 0.01, 0.13) up to age 10 years. These associations were explained by protein from animal sources and not plant sources. Associations were independent of protein intake and overall diet quality at age 8 years, and were independent of whether higher protein was consumed at the expense of carbohydrates or fat in the diet.

CONCLUSIONS

Our study suggests that high protein intake in infancy, particularly from animal food sources, is persistently associated with adiposity up to age 10 years. Restricting protein intake in this critical period of development may aid in the early prevention of adiposity in childhood.

Does milk intake promote prostate cancer initiation or progression via effects on insulin-like growth factors (IGFs)? A systematic review and meta-analysis

PURPOSE

To establish whether the association between milk intake and prostate cancer operates via the insulin-like growth factor (IGF) pathway (including IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3).

METHODS

Systematic review, collating data from all relevant studies examining associations of milk with IGF, and those examining associations of IGF with prostate cancer risk and progression. Data were extracted from experimental and observational studies conducted in either humans or animals, and analyzed using meta-analysis where possible, with summary data presented otherwise.

RESULTS

One hundred and seventy-two studies met the inclusion criteria: 31 examining the milk-IGF relationship; 132 examining the IGF-prostate cancer relationship in humans; and 10 animal studies examining the IGF-prostate cancer relationship. There was moderate evidence that circulating IGF-I and IGFBP-3 increase with milk (and dairy protein) intake (an estimated standardized effect size of 0.10 SD increase in IGF-I and 0.05 SD in IGFBP-3 per 1 SD increase in milk intake). There was moderate evidence that prostate cancer risk increased with IGF-I (Random effects meta-analysis OR per SD increase in IGF-I 1.09; 95% CI 1.03, 1.16; n = 51 studies) and decreased with IGFBP-3 (OR 0.90; 0.83, 0.98; n = 39 studies), but not with other growth factors. The IGFBP-3 -202A/C single nucleotide polymorphism was positively associated with prostate cancer (pooled OR for A/C vs. AA = 1.22; 95% CI 0.84, 1.79; OR for C/C vs. AA = 1.51; 1.03, 2.21, n = 8 studies). No strong associations were observed for IGF-II, IGFBP-1 or IGFBP-2 with either milk intake or prostate cancer risk. There was little consistency within the data extracted from the small number of animal studies. There was additional evidence to suggest that the suppression of IGF-II can reduce tumor size, and contradictory evidence with regards to the effect of IGFBP-3 suppression on tumor progression.

CONCLUSION

IGF-I is a potential mechanism underlying the observed associations between milk intake and prostate cancer risk.

Scientific Opinion on the safety and suitability for use by infants of follow-on formulae with a protein content of at least 1.6 g/100 kcal

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the safety and suitability for use by infants of follow-on formulae (FOF) based on cow's milk intact protein with a protein content of at least 1.6 g/100 kcal (rounded value) that meet otherwise the requirements of relevant EU legislation. If the formula under evaluation is considered to be safe and suitable for use by infants, the NDA Panel is also asked to advise on whether FOF based on goat's milk intact protein, soy protein isolates or protein hydrolysates are also safe and suitable for infants under the same conditions. The Panel concludes that the use of FOF with a protein content of at least 1.6 g/100 kcal from either intact cow's milk protein or intact goat's milk protein otherwise complying with the requirements of relevant EU legislation is safe and suitable for healthy infants living in Europe with an intake of complementary foods of a sufficient quality. This conclusion does not apply to infant formula (IF). The Panel also concludes that the safety and suitability of FOF with a protein content of at least 1.6 g/100 kcal manufactured from either protein hydrolysates or soy protein isolates cannot be established with the available data. The same conclusion applies to IF. The NDA Panel endorsed a draft of this scientific opinion on 14 December 2016 for public consultation. The draft document has been revised and updated according to the comments received, where appropriate.

Dietary Intake of Protein in Early Childhood Is Associated with Growth Trajectories between 1 and 9 Years of Age

BACKGROUND

High protein intake in infancy might lead to a higher body mass index (BMI) in childhood. However, whether these associations differ between different sources of protein is unclear.

OBJECTIVE

We investigated associations between the intake of total protein, protein from different sources, and individual amino acids in early childhood and repeatedly measured height, weight, and BMI up to the age of 9 y.

METHODS

This study was performed in 3564 children participating in the Generation R Study, a population-based prospective cohort study in Rotterdam, Netherlands. Intakes of total protein, animal protein, vegetable protein, and individual amino acids (including methionine, arginine, lysine, threonine, valine, leucine, isoleucine, phenylalanine, tryptophan, histidine, cysteine, tyrosine, alanine, asparagine, glutamine, glycine, proline, and serine) at 1 y were assessed by using a food-frequency questionnaire. Height and weight were measured at the approximate ages of 14, 18, 24, 30, 36, and 45 mo and at 6 and 9 y, and BMI was calculated.

RESULTS

After adjustment for confounders, linear mixed models showed that a 10-g higher total protein intake/d at 1 y was significantly associated with a 0.03-SD greater height (95% CI: 0.00, 0.06), a 0.06-SD higher weight (95% CI: 0.03, 0.09), and a 0.05-SD higher BMI (95% CI: 0.03, 0.08) up to the age of 9 y. Associations were stronger for animal than for vegetable protein intake but did not differ between dairy and nondairy animal protein or between specific amino acids.

CONCLUSIONS

A higher intake of protein, especially animal protein, at 1 y of age was associated with a greater height, weight, and BMI in childhood up to 9 y of age. Future studies should explore the role of growth hormones and investigate whether protein intake in early childhood affects health later in life.

Vitamin D Intake and Status in 6-Year-Old Icelandic Children Followed up from Infancy

High serum 25-hydroxyvitamin D (25(OH)D) levels have been observed in infants in Nordic countries, likely due to vitamin D supplement use. Internationally, little is known about tracking vitamin D status from infancy to childhood. Following up 1-year-old infants in our national longitudinal cohort, our aims were to study vitamin D intake and status in healthy 6-year-old Icelandic children (n = 139) and to track vitamin D status from one year of age. At six years, the mean 25(OH)D level was 56.5 nmol/L (SD 17.9) and 64% of children were vitamin D sufficient (25(OH)D ≥ 50 nmol/L). A logistic regression model adjusted for gender and breastfeeding showed that higher total vitamin D intake (Odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.08–1.49), blood samples collected in summer (OR = 8.88, 95% CI = 1.83–43.23) or autumn (OR = 5.64, 95% CI = 1.16–27.32) compared to winter/spring, and 25(OH)D at age one (OR = 1.02, 95% CI = 1.002–1.04) were independently associated with vitamin D sufficiency at age six. The correlation between 25(OH)D at age one and six was 0.34 (p = 0.003). Our findings suggest that vitamin D status in infancy, current vitamin D intake and season are predictors of vitamin D status in early school age children. Our finding of vitamin D status tracking from infancy to childhood provides motivation for further studies on tracking and its clinical significance.

Regulation of early human growth: impact on long-term health

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.

Animal protein intake at 12 months is associated with growth factors at the age of six

AIM

To study the associations between protein intake from different sources with anthropometry and serum insulin-like growth factor 1 (IGF-1) in infancy and childhood.

METHODS

Children (n = 199) born in Iceland were followed up to six years of age. Their intake of various animal proteins and vegetable protein was calculated from weighed food records at 12 months and 6 years. Information about their weight and height at birth, 12 and 18 months, and 6 years was gathered. Serum IGF-1 was measured at 12 months and 6 years.

RESULTS

At the age of six, children in the highest quartile for animal protein intake at 12 months (≥12.2% of total energy) had 0.8 kg/m(2) (95% CI = 0.1, 1.5) higher body mass index (BMI) than children in the lowest quartile (<7.6% of total energy). They were also heavier and longer in infancy and childhood. At 12 months, dairy protein intake as a percentage of total energy was associated with IGF-1 in six-year-old girls, β = 5.4 μg/L (95% CI = 2.5, 8.2).

CONCLUSION

High animal protein intake in infancy, but not vegetable protein intake, was associated with accelerated growth and higher BMI in childhood. Dairy protein intake in infancy may be positively associated with linear growth and also with IGF-1 in six-year-old girls.

Complementary feeding and obesity risk

PURPOSE OF REVIEW

This article will summarize recent progress in research in the area of complementary feeding as it relates to childhood obesity. Newly emerged findings demonstrate how research on contributing factors has shifted. Examining nutrient and caloric intakes alone has failed to answer the critical question, 'Why are some children obese, whereas others are not?' Recent research explores parental attitudes, beliefs and parental feeding styles as contributing factors.

RECENT FINDINGS

Studies examining the impact of specific macronutrients on obesity risk may have partially uncovered a link between consistently high protein intakes during infancy and an elevated obesity risk, at least until the second year of life. However, this relationship was not evident in all studies evaluated in a systematic review this year. Childhood obesity is not linked to any specific types of foods or food groups during the complementary feeding period. Adherence to dietary guidelines is associated with increased lean body mass, but not BMI or fat mass. Complementary feeding practices, socioeconomic and other family dynamics at least partially explain obesity risk.

SUMMARY

As young infants are dependent on adults for nourishment, parental attitudes and beliefs about infant nutrition and actual feeding practices directly influence infant nutritional status. Early nutrition interventions to prevent obesity should take nutrition belief systems, parental feeding styles, socioeconomic and educational status, among other characteristics into consideration.

Exclusive breastfeeding for 4 versus 6 months and growth in early childhood

AIM

To investigate the growth and the prevalence of overweight in early childhood among infants exclusively breastfed for 6 months (EBF) compared with those receiving complementary foods from 4 months of age in addition to breast milk (CF).

METHODS

A total of 119 mother-infant pairs were randomised either in the CF or in the EBF group. Weight, length and head circumference of the infants were measured at birth, 6 weeks, and 3-6 months of age. In the follow-up, the children's weight, length and head circumference were measured at 8, 10, 12 and 18 months and weight and height at 29-38 months.

RESULTS

There were no differences between groups in the anthropometric outcome measures of weight-for-age (p = 0.78), length-for-age (p = 0.59), head-circumference-for-age (p = 0.82) and BMI-for-age (p = 0.61), using repeated measurements ANOVA. Furthermore, no difference was seen in the prevalence between groups in risk of being overweight or in those who were overweight at 18 months and 29-38 months of age.

CONCLUSION

Exclusive breastfeeding for the first 4 or 6 months of life does not seem to affect the risk of being overweight or the prevalence of those who were overweight in early childhood.