Effects of protein intake on blood pressure, insulin sensitivity and blood lipids in children: a systematic review

Protein - a scoping review for Nordic Nutrition Recommendations 2023

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body's needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

Protein Intake, Source and Effect on Children's Weight Status: An Epidemiological Study in Greece

The development of overweight and obesity during late childhood and early adolescence is one of the most critical issues in public health. Additionally, over the past few years, the consumption of protein has tended to increase in both children and adults. The present study aimed to evaluate whether the protein type, either plant- or animal-sourced, as well as the quantity consumed, could potentially have a relationship with excess body weight in children. A total of 47 primary schools were selected, and 1728 students, aged 10-12 years, were enrolled for the purposes of this study, leading to our final sample of 712. Physical measurements, such as weight and height, were measured, and children were separated into two weight status categories according to their Body Mass Index, which was obtained through the International Obesity Task Force criteria. Students' diets were assessed through a questionnaire, and total, plant- and animal-derived protein intakes were calculated. Unadjusted analysis showed a statistically significant association between body weight and plant protein. After adjustment for overall energy intake, sex, age, and exercise, there was a statistically significant negative association between plant protein and excess body weight in children (OR: 0.964, 95% CI: 0.936; 0.992), but a lack of association for animal-sourced protein (OR: 1.002, 95% CI: 0.991; 1.013). Dietary plant-derived protein seems to have a positive effect on weight status in children, independently of total energy intake and physical activity; nevertheless, additional research is required in order to elucidate the underlying mechanisms.

Review: A systematic review of the effects of functional amino acids on small intestine barrier function and immunity in piglets

The need to reduce the use of antibiotics and zinc oxide at the pharmacological level, while preserving the performance of postweaning piglets, involves finding adequate nutritional strategies which, coupled with other preventive strategies, act to improve the sustainability of the piglet-rearing system. Amino acids (AAs) are the building blocks of proteins; however, they also have many other functions within the body. AA supplementation, above the suggested nutritional requirement for piglets, has been investigated in the diets of postweaning piglets to limit the detrimental consequences occurring during this stressful period. A systematic review was carried out to summarise the effects of AAs on gut barrier function and immunity, two of the parameters contributing to gut health. An initial manual literature search was completed using an organised search strategy on PubMed, utilising the search term " AND ". These searches yielded 302 articles (published before October 2021); 59 were selected. Based on the method for extracting data (synthesis of evidence), this review showed that L-Arginine, L-Glutamine and L-Glutamate are important functional AAs playing major roles in gut morphology and immune functions. Additional benefits of AA supplementation, refereed to a supplementation above the suggested nutritional requirement for piglets, could also be observed; however, data are needed to provide consistent evidence. Taken together, this review showed that supplementation with AAs during the weaning phase supported a plethora of the physiological functions of piglets. In addition, the data reported confirmed that each amino acid targets different parameters related to gut health, suggesting the existence of potential synergies among them.

Dietary patterns acquired in early life are associated with cardiometabolic markers at school age

BACKGROUND & AIMS

it has previously been described that dietary patterns established early in life tracked to late childhood. The aim of the present work was to analyse the association of dietary patterns that tracked from 2 to 8y with cardiometabolic markers at 8y of age.

METHODS

The 3 identified patterns at 2y (that previous analyses showed to track to age 8y) were: "Core_DP", loaded for vegetables, fruits, fish, olive oil, etc.; "F&S_DP", loaded by poor-quality fats and sugars; and "Protein_DP", mainly loaded by animal protein sources. Cardiometabolic markers at 8y were systolic blood pressure (SBP), insulin resistance (HOMA-IR), and triglycerides, and BMI z-score. To examine whether the association of diet with the outcomes was the result of a direct effect of diet at either two or 8y, or synergy between them, we used structural equation models.

RESULTS

the associations between the patterns and the health outcomes were: Core_DP was inversely associated with SBP and HOMA-IR; Protein_DP was directly associated with HOMA-IR and SBP; and adherence to F&S_DP was directly associated with triglycerides and SBP. The associations between the patterns and the health outcomes were independent of BMI and were the result of a direct effect of diet at 2y, an indirect effect of diet at 2y through diet at 8y or a combination between both pathways.

CONCLUSION

dietary patterns acquired in early life, persisting to later childhood, were associated with cardiometabolic markers at school age independently of BMI.

Protein Intake During Infancy and Subsequent Body Mass Index in Early Childhood: Results from the Melbourne InFANT Program

BACKGROUND

The link between high protein intake during infancy and obesity later in childhood has been much debated, and the association with differing protein sources remains unclear.

OBJECTIVE

This study aimed to examine the associations between total protein intake and protein from different sources (ie, nondairy animal, dairy, and plant) reported at age 9 months and development in body mass index (BMI) z scores until age 5 years.

DESIGN

This study involved a secondary data analysis of the Melbourne InFANT (Infant Feeding, Activity and Nutrition Trial) program, an observational prospective cohort study that was conducted from 2008 to 2013.

PARTICIPANTS/SETTING

Participants were children (n = 345) who completed both the 9-month and 5-year follow-up visits within the Melbourne InFANT program.

MAIN OUTCOME MEASURES

BMI z score was measured at age 5 years.

STATISTICAL ANALYSES PERFORMED

Linear mixed models with a random effect for clusters of mother's group and with adjustment for baseline child and maternal covariates were conducted.

RESULTS

With adjustment for covariates, every 1 g or 1% energy increase in total protein intake at age 9 months was associated with a 0.016-unit (95% CI 0.003 to 0.029) or 0.034-unit (95% CI 0.005 to 0.063) increase in BMI z score at age 5 years, respectively. With respect to protein sources, associations of similar magnitude were found for nondairy animal protein. No evidence of an association with BMI z score was found for dairy (including milk, yogurt, cheese, breast milk, and infant formula) and plant proteins.

CONCLUSIONS

High intakes of total protein, nondairy animal protein, but not dairy or plant proteins, during infancy were associated with higher BMI z score in early childhood. These findings can inform dietary recommendations regarding protein intakes during infancy.

CLINICAL TRIAL REGISTRATION

The InFANT program was registered with Current Controlled Trials (ISRCTN81847050); http://www.isrctn.com/ISRCTN81847050.

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

There is accumulating evidence that early protein intake is related with weight gain in childhood. However, the evidence is mostly limited to the first year of life, whereas the high-weight-gain-velocity period extends up to about 2 years of age. We aimed to investigate whether protein intake during the second year of life is associated with higher weight gain and obesity risk later in childhood. We conducted a systematic review with searches in both PubMed®/MEDLINE® and the Cochrane Central Register of Controlled Trials. Ten studies that assessed a total of 46,170 children were identified. We found moderate-quality evidence of an association of protein intake during the second year of life with fat mass at 2 years and at 7 years. Effects on other outcomes such as body mass index (BMI), obesity risk, or adiposity rebound onset were inconclusive due to both heterogeneity and low evidence. We conclude that higher protein intakes during the second year of life are likely to increase fatness in childhood, but there is limited evidence regarding the association with other outcomes such as body mass index or change in adiposity rebound onset. Further well-designed and adequately powered clinical trials are needed since this issue has considerable public health relevance.

Evidence for Protein Leverage in Children and Adolescents with Obesity

OBJECTIVE

The aim of this study was to test the protein leverage hypothesis in a cohort of youth with obesity.

METHODS

A retrospective study was conducted in a cohort of youth with obesity attending a tertiary weight management service. Validated food questionnaires revealed total energy intake (TEI) and percentage of energy intake from carbohydrates (%EC), fats (%EF), and proteins (%EP). Individuals with a Goldberg cutoff ≥ 1.2 of the ratio of reported TEI to basal metabolic rate from fat-free mass were included. A subgroup had accelerometer data. Statistics included modeling of percentage of energy from macronutrients and TEI, compositional data analysis to predict TEI from macronutrient ratios, and mixture models for sensitivity testing.

RESULTS

A total of 137 of 203 participants were included (mean [SD] age 11.3 [2.7] years, 68 females, BMI z score 2.47 [0.27]). Mean TEI was 10,330 (2,728) kJ, mean %EC was 50.6% (6.1%), mean %EF was 31.6% (4.9%), and mean %EP was 18.4% (3.1%). The relationship between %EP and TEI followed a power function (L coefficient -0.48; P < 0.001). TEI was inversely associated with increasing %EP. In the subgroup with < 60 min/d of moderate to vigorous physical activity (n = 48), lower BMI z scores were associated with higher %EP and moderate %EC.

CONCLUSIONS

In youth with obesity, protein dilution by either carbohydrates or fats increases TEI. Assessment of dietary protein may be useful to assist in reducing TEI and BMI in youth with obesity.

A Systematic Review of Principal Component Analysis-Derived Dietary Patterns in Japanese Adults: Are Major Dietary Patterns Reproducible Within a Country?

Principal component analysis (PCA) has been widely used in nutritional epidemiology to derive dietary patterns. However, although PCA-derived dietary patterns are population-dependent, their reproducibility in different populations is largely unexplored. We aimed to investigate whether major dietary patterns are consistently identified among different populations within a country and, if so, how similar these dietary patterns are. We conducted a systematic review of PCA-derived dietary patterns in Japanese adults using PubMed and Web of Science for English articles and Ichushi-Web and CiNii databases for Japanese articles. We assessed the reproducibility of major dietary patterns using congruence coefficients (CCs), with values ≥0.80 considered to represent fair similarity. From 65 articles (80 studies) included in this review, 285 different dietary patterns were identified. Based on the names of these patterns, major dietary patterns were Western (n = 34), Japanese (n = 12), traditional (n = 10), traditional Japanese (n = 9), healthy (n = 18), and prudent (n = 9) patterns. When assessment was limited to high-quality data (i.e., studies based on a sample size ≥200 and use of a validated dietary assessment questionnaire or multiple-day dietary record), the median CC was low for Western (0.44), traditional (0.59), and traditional Japanese (0.31) patterns. Conversely, the median CC was 0.89 for healthy, 0.86 for prudent, and 0.80 for Japanese patterns; and the proportion of pairs with a CC ≥0.80 was 87.3%, 64.3%, and 50.0%, respectively. Characteristics shared among these 3 dietary patterns included higher intakes of mushrooms, seaweeds, vegetables, potatoes, fruits, pulses, and pickles. In conclusion, this systematic review showed that some of the major dietary patterns are relatively reproducible in different populations within a country, whereas others are not. This highlights the importance of careful interpretation of PCA-derived dietary patterns. Our findings in Japan should be confirmed in different countries and globally. This study was registered at https://www.crd.york.ac.uk/prospero/ as CRD42018087669.

Associations between dietary factors and obesity-related biomarkers in healthy children and adolescents - a systematic review

Background

The obesity prevalence in children and adolescents has increased worldwide during the past 30 years. Although diet has been identified as one risk factor for developing obesity in this age group, the role of specific dietary factors is still unclear. One way to gain insight into the role of these factors might be to detect biomarkers that reflect metabolic health and to identify the associations between dietary factors and these biomarkers. This would enable nutrition-related metabolic changes to be detected early in life, which might be a promising strategy to prevent childhood obesity. However, existing literature offers only inconclusive evidence for diet and some of these obesity-related biomarkers (e.g., blood lipids). We thus conducted a systematic literature review to further examine eligible studies that investigate associations between dietary factors and 12 obesity-related biomarkers in healthy children and adolescents aged 3-18 years.

Methods

We searched the scientific databases PubMed/Medline and Web of Science Core Collection for potentially eligible articles. Our final literature search resulted in 2727 hits. After the selection process, we included 81 articles that reported on 1111 single observations on dietary factors and any of the obesity-related biomarkers.

Results

Around 81% of the total observations showed nonsignificant results. For many biomarkers we did not find enough observations to draw clear conclusions on possible associations between a dietary factor and the respective biomarker. In cases where we identified enough observations, the results were contradictory. Since these nonsignificant and inconclusive findings may impede the development of effective strategies against childhood obesity, this article takes a closer look at possible reasons for such findings. In addition, it provides action points for future research efforts.

Conclusions

In conclusion, current evidence on associations between dietary factors and obesity-related biomarkers is inconclusive. We thus provided an overview on which specific limitations may impede current research. Such knowledge is necessary to enable future research efforts to better elucidate the role of diet in the early stages of obesity development.

Electronic supplementary material

The online version of this article (10.1186/s12937-017-0300-3) contains supplementary material, which is available to authorized users.

Maternal weight status, diet, and supplement use as determinants of breastfeeding and complementary feeding: a systematic review and meta-analysis

CONTEXT

Infant feeding practices are influenced by maternal factors.

OBJECTIVE

The aim of this review is to examine the associations between maternal weight status or dietary characteristics and breastfeeding or complementary feeding.

DATA SOURCES

A systematic literature search of the Embase, Cochrane Library, Google Scholar, MEDLINE, PubMed, and Web of Science databases was performed.

STUDY SELECTION

Interventional and cohort studies in healthy mothers and infants that reported on maternal weight status, diet, or supplement use were selected.

DATA EXTRACTION

Outcomes assessed included delayed onset of lactogenesis; initiation, exclusivity, duration, and cessation of breastfeeding; and timing of complementary feeding.

DATA ANALYSIS

Eighty-one studies were included. Maternal underweight, diet, and supplement use were not associated with infant feeding practices. Obese women had a relative risk of failure to initiate breastfeeding (risk ratio [RR] = 1.23; 95%CI, 1.03-1.47) and a delayed onset of lactogenesis (RR  =  2.06; 95%CI, 1.18-3.61). The RR for breastfeeding cessation was 1.11 (95%CI, 1.07-1.15) per increase in category of body mass index.

CONCLUSIONS

Prevention of obesity in women of reproductive age, as well as counseling of obese women after delivery, could be targeted to improve infant feeding practices.

Protein intake in early childhood and body composition at the age of 6 years: The Generation R Study

BACKGROUND

Previous studies suggest that high protein intake in infancy leads to a higher body mass index (BMI) in later childhood. We examined the associations of total, animal and vegetable protein intake in early childhood with detailed measures of body composition at the age of 6 years.

METHODS

This study was performed in 2911 children participating in a population-based cohort study. Protein intake at the age of 1 year was assessed with a validated food-frequency questionnaire and was adjusted for total energy intake. At the children's age of 6 years, we measured their anthropometrics and body fat (with dual-energy X-ray absorptiometry). We calculated age- and sex-specific s.d. scores for BMI, fat mass index (FMI) and fat-free mass index (FFMI).

RESULTS

After adjustment for confounders, a 10 g per day higher total protein intake at 1 year of age was associated with a 0.05 s.d. (95% confidence interval (CI) 0.00, 0.09) higher BMI at age 6. This association was fully driven by a higher FMI (0.06 s.d. (95%CI 0.01, 0.11)) and not FFMI (-0.01 s.d. (95%CI -0.06, 0.05)). The associations of protein intake with FMI at 6 years remained significant after adjustment for BMI at the age of 1 year. Additional analyses showed that the associations of protein intake with FMI were stronger in girls than in boys (P for interaction=0.03), stronger among children who had catch-up growth in the first year of life (P for interaction<0.01) and stronger for intake of animal protein (both dairy and non-dairy protein) than protein from vegetable sources.

CONCLUSIONS

Our results suggest that high protein intake in early childhood is associated with higher body fat mass, but not fat-free mass. Future studies are needed to investigate whether these changes persist into adulthood and to examine the optimal range of protein intake for infants and young children.

Protein intake in early childhood and cardiometabolic health at school age: the Generation R Study

Purpose

High protein intake in infancy has been linked to obesity. We aimed to examine the associations of protein intake in early childhood with cardiovascular and metabolic outcomes at school age.

Methods

This study was performed in 2965 children participating in a population-based prospective cohort study. Protein intake at 1 year was assessed with a food frequency questionnaire and was adjusted for energy intake. At the children’s age of 6 years, we measured their body fat percentage (BF%), blood pressure (BP), and insulin, HDL cholesterol, and triglyceride serum levels. These measures were incorporated into a cardiometabolic risk factor score, using age- and sex-specific SD scores.

Results

In covariate-adjusted models, higher protein intake was associated with a higher BF%, lower diastolic BP, and lower triglyceride levels. We observed a significant interaction of protein intake with child sex on metabolic outcomes. Stratified analyses showed that protein intake was positively associated with BF% [0.07 SD (95 % CI 0.02; 0.13) per 10 g/day] and insulin levels in girls, but not in boys. In boys, but not in girls, higher protein intake was associated with lower triglyceride levels [−0.12 SD (95 % CI −0.20; −0.04) per 10 g/day] and a lower cardiometabolic risk factor score. Protein intake was not consistently associated with systolic BP or HDL cholesterol levels.

Conclusion

Protein intake in early childhood was associated with a higher BF% and higher insulin levels at 6 years in girls and with lower triglyceride levels in boys. Further studies are needed to explore these sex differences and to investigate whether the observed changes persist into adulthood.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-015-1026-7) contains supplementary material, which is available to authorized users.

Effects of polyunsaturated fatty acid intake and status during pregnancy, lactation, and early childhood on cardiometabolic health: A systematic review

The importance of polyunsaturated fatty acid (PUFA) intake in fetal life and infancy has been widely studied in relation to child cognitive and visual development, but whether early life PUFA exposure is related to cardiometabolic risk factors is unclear. The focus of this systematic review was to evaluate the effects of PUFA dietary intake and blood levels during pregnancy, lactation, or early childhood (⩽5 y) on obesity, blood pressure, blood lipids, and insulin sensitivity. We identified 4302 abstracts in the databases Embase, Medline and Cochrane Central (April 2014), of which 56 articles, reporting on 45 unique studies, met all selection criteria. Many of the included studies focused on obesity as an outcome (33 studies), whereas studies on insulin sensitivity were relatively scarce (6 studies). Overall, results for obesity, blood pressure, and blood lipids were inconsistent, with a few studies reporting effects in opposite directions and other studies that did not observe any effects of PUFAs on these outcomes. Four studies suggested beneficial effects of PUFAs on insulin sensitivity. We conclude that there is insufficient evidence to support a beneficial effect of PUFAs in fetal life or early childhood on obesity, blood pressure, or blood lipids. More research is needed to investigate the potential favorable effects of PUFAs on insulin sensitivity, and to examine the role of specific fatty acids in early life on later cardiometabolic health.