Association between dietary protein and change in body composition among children (EYHS)

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

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

Body Composition in Adolescent PKU Patients: Beyond Fat Mass

There is a lack of evidence on the impact on body composition of high protein intake and types of protein substitutes in PKU patients—particularly in adolescents, who are more inclined to dietary transgressions. In this observational, cross-sectional study, PKU patients were observed during prepubertal age (p) or after the pubertal spurt (P), assessing body composition and bone quality and correlating these parameters with dietary compliance and types of protein substitutes. Anthropometric and dietary data were evaluated together with bioelectrical impedance analysis (BIA), quantitative ultrasound (QUS) and branched-chain amino acids (BCAAs). A total of 36 patients (16 males, 17 prepubertal and 19 post-pubertal; mean ± SD age 11.4 ± 3.9 years) were included. A higher BMI was observed in adolescents (p-value: 0.018). The BIA revealed a significant increase in total body water (TBW) and muscle mass (MM) in P subjects either compliant (p-value: 0.001) or non-compliant with the diet (p-value: 0.001). MM content correlated with increased Phe intake (r = 0.63; p < 0.001). In the subgroup of five patients taking L-AAs and glycomacropeptides (GMPs), BCAA values tended to be lower than those taking only L-AA mixtures, with a significant trend for valine. Maintenance of body composition parameters within the normal range—for both fat and muscle mass—and levels of BCAAs can be helpful in reducing the risk of becoming overweight in adulthood. Further studies are needed to confirm these findings.

Effects of high dairy protein intake and vitamin D supplementation on body composition and cardiometabolic markers in 6-8-y-old children-the D-pro trial

BACKGROUND

Increasing evidence suggests that prevention of lifestyle diseases should begin early. Dairy protein and vitamin D can affect body composition and cardiometabolic markers, yet evidence among well-nourished children is sparse.

OBJECTIVES

We investigated combined and separate effects of high dairy protein intake and vitamin D on body composition and cardiometabolic markers in children.

METHODS

In a 2 × 2-factorial, randomized trial, 200 white, Danish, 6-8-y-old children substituted 260 g/d dairy in their diet with high-protein (HP; 10 g protein/100 g) or normal-protein (NP; 3.5 g protein/100 g) yogurt and received blinded tablets with 20 µg/d vitamin D3 or placebo for 24 wk during winter. We measured body composition (by DXA), blood pressure, and fasting blood glucose, insulin, C-peptide, and lipids.

RESULTS

In total, 184 children (92%) completed the study. Baseline median (25th-75th percentile) dairy protein intake was median: 3.7 (25th-75th percentile: 2.5-5.1) energy percentage (E%) and increased to median: 7.2 (25th-75th percentile: 4.7-8.8) E% and median: 4.2 (25th-75th percentile: 3.1-5.3) E% with HP and NP. Mean ± SD serum 25-hydroxyvitamin D concentration changed from 81 ± 17 to 89 ± 18 nmol/L and 48 ± 13 nmol/L with vitamin D and placebo, respectively. There were no combined effects of dairy protein and vitamin D, except for plasma glucose, with the largest increase in the NP-vitamin D group (Pinteraction = 0.005). There were smaller increases in fat mass index (P = 0.04) with HP than with NP, and the same pattern was seen for insulin, HOMA-IR, and C-peptide (all P = 0.06). LDL cholesterol was reduced with vitamin D compared with placebo (P < 0.05). Fat-free mass and blood pressure were unaffected.

CONCLUSIONS

High compared with normal dairy protein intake hampered an increase in fat mass index. Vitamin D supplementation counteracted the winter decline in 25-hydroxyvitamin D and the increase in LDL cholesterol observed with placebo. This study adds to the sparse evidence on dairy protein in well-nourished children and supports a vitamin D intake of ∼20 µg/d during winter. This trial was registered at clinicaltrials.gov as NCT03956732.

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.

Dietary intake and nutritional status of patients with phenylketonuria in Taiwan

Phenylalanine hydroxylase (PAH) deficiency leads to phenylalanine accumulation and results in phenylketonuria (PKU). Phenylketonuria can contribute to severe inability such as mental impairment. Early diagnosis and dietary intervention can have beneficial effects on maintaining normal neural and cognitive function in patients with PKU. However, a long-term low phenylalanine diet may put children at risk of malnutrition. A food supplement was therefore used for children with PKU under dietician supervision according to dietary reference intakes (DRIs). In this cross-sectional study, we enrolled patients with PKU and age-matched controls to compare their anthropometry data [weight, height, body mass index (BMI), and body composition using bioelectrical impedance analysis (BIA)], and correlated it with their dietary intake based on 24-h dietary recall. For continuous parameters, the data were expressed as median ± standard deviation (SD), and the Mann–Whitney U test was used to test the difference among the groups. Correlation by natural proteins, body fat, and fat-free mass were evaluated using the Pearson correlation coefficient. Twenty-two participants diagnosed with PKU (ages 8–27 years; mean 15.23 ± 5.23) and a control group of 22 non-PKU participants (ages 8–39 years; mean 19.73 ± 10.6) were recruited for this study. Between the two groups of participants, no significant difference was found in height, weight, BMI, muscle mass, or fat mass. The percentage of natural protein has no effect on body composition. We found a significant positive correlation between the total protein intake percentage of DRIs and muscle mass (r = 0.491, p = 0.020) and a significant negative correlation in the total protein intake percentage of DRIs and fat mass (r = -0.475, p = 0.025) in participants with PKU. There were no significant differences in body composition and nutrition intake between patients with PKU (under metabolic control) and healthy subjects. Thus, giving proper nutrition treatment may have beneficial effects on body growth and nutrition status in patients with PKU in Taiwan.

Dietary protein intake in school-age children and detailed measures of body composition: the Generation R Study

BACKGROUND

A high-protein diet in infancy increases the risk of obesity, but the effects of dietary protein intake in mid-childhood on body composition are unclear. Therefore, we studied associations of protein intake (total, animal and plant-sourced) at 8 years of age with anthropometric measures and body composition up to age 10 years.

METHODS

We included 3991 children of the Generation R Study, a prospective cohort in the Netherlands. Dietary protein intake was assessed at 8 years of age using a food-frequency questionnaire and is expressed in energy percentage (E%). Anthropometric measures and body composition (using dual-energy X-ray absorptiometry (DXA)) were assessed at 6 years and during follow-up at 10 years. We calculated body mass index (BMI), fat mass index (FMI), and fat-free mass index (FFMI). All outcomes were sex- and age-standardized and overweight (yes/no) was derived from BMI-SDS. We examined associations of protein intake at 8 years with the combined risk of overweight and obesity, and body composition at 10 years using multivariable logistic and linear regression models. These analyses were adjusted for outcomes at 6 years and protein intake in early life.

RESULTS

In multivariable-adjusted models, a 5E% higher protein intake at 8 years was associated with a higher combined risk of overweight and obesity up to 10 years (odds ratio (OR) 1.51, 95% confidence interval (CI): 1.22,1.86), independent of whether it replaced carbohydrates or fat. However, this was mainly explained by an association of protein intake with a higher FFMI (0.07 standard deviation scores (SDS) per 5E%, 95% CI: 0.02,0.11), not FMI. Both plant and animal were associated with a higher FFMI, but the association was stronger for protein from plant sources. For FMI, our findings also suggest trends of higher plant protein intake with lower FMI, and higher animal protein intake with higher FMI. Following this, a higher plant protein intake at the expense of animal protein was associated with a lower FMI (-0.08 SDS per 5E%, 95% CI: -0.15,-0.01).

CONCLUSIONS

We observed that a higher protein intake in mid-childhood is associated with a higher fat-free mass. Our findings also suggest that protein from plant sources seems to be beneficial for body composition in school-age children.

The Relationship between Dietary Intake, Growth, and Body Composition in Inborn Errors of Intermediary Protein Metabolism

OBJECTIVES

To examine relationships between dietary intake, growth and body composition patterns in patients with inborn errors of intermediary protein metabolism and to determine a safe protein:energy ratio (P:E ratio) associated with optimal growth outcomes.

STUDY DESIGN

Retrospective longitudinal data of growth and dietary intake in patients (n = 75) with isovaleric acidemia (IVA; n = 7), methylmalonic acidemia/propionic acidemia (MMA/PA; n = 14), urea cycle defects (UCD; n = 44), classical maple syrup urine disease (MSUD; n = 10) were collected. Prospective longitudinal data of growth, dietary intake, and body composition from 21 patients: IVA (n = 5), MMA/PA (n = 6), UCD (n = 7), and MSUD (n = 3) were collected at clinic visits.

RESULTS

Fifty-two of 75 (66%), 49 of 74 (68%), and 44 of 65 (68%) patients had a z-score of 0 (±1) for lifetime weight, height, and body mass index, respectively. Patients with MMA/PA had the lowest median height and weight z-scores, and MSUD patients had highest median body mass index z-score at all ages. In IVA, MMA/PA, and UCD, total natural protein intake met or exceeded the Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO)/United Nations University (UNU) recommended safe levels. Median percentage fat mass was 17.6% in IVA, 20.7% in MMA/PA, 19.4% in UCD, and 17.8% in MSUD. There was a significant negative correlation between percentage fat mass and total protein intake in IVA, MMA/PA, and UCD (r = -0.737; P = .010). The correlation between the P:E ratio and growth variables in IVA, MMA/PA, and UCD suggest a safe P:E ratio (>1.5 to < 2.9) g protein:100 kcal/day.

CONCLUSION

Growth outcomes in inborn errors of intermediary protein metabolism are not always ideal. Most patients with IVA, MMA/PA, and UCD consume sufficient natural protein to meet FAO/WHO/UNU recommendations. A P:E ratio range of (>1.5 to < 2.9)g protein/100 kcal/day correlates with optimal growth outcomes.

The relationship between dietary intake, growth and body composition in Phenylketonuria

AIM

Phenylketonuria (PKU) is an inborn error of protein metabolism that results from perturbation in phenylalanine hydroxylase activity leading to elevated blood levels of phenylalanine (phe). We aimed to explore the relationships between dietary patterns (total-protein, natural-protein, amino-acid formula), and the ratio of protein to energy intake with growth and body composition.

METHOD

Longitudinal prospective data (1-6 measurements) of growth, dietary intake and body composition in patients treated with phe-restricted diet only (D-PKU; n=32), and tetrahydrobiopterin (BH₄)±phe-restricted diet (BH₄-PKU; n=5) were collected over a two-year period. Healthy siblings provided control data (n=21).

RESULTS

There were no significant differences in weight-, height-, BMI z-score or percent body fat mass (%fatmass) between the D-PKU, BH₄-PKU and control groups or between the all-types of PKU combined and controls, which confirmed 'normal' growth in the PKU cohort. Total-protein intake in the all-types of PKU group met or exceeded WHO safe protein recommendations. There were no significant relationships between anthropometric and dietary variables. Significant negative correlations were found in body composition: %fatmass and total-protein intake (r_s=-0.690, p≤0.001), natural-protein intake (r_s=-0.534, p=0.001), and AAF intake (r_s=-0.510, p=0.001). Age was significantly correlated with %fatmass (r_s=0.493, p=0.002) A total-protein intake of 1.5-2.6g/kg/day and natural-protein intake >0.5g/kg/day were associated with improved body composition. An apparent safe P:E ratio of 3.0-4.5g protein/100kcal was strongly associated with appropriate growth outcomes.

CONCLUSIONS

Clinical decision-making needs to consider both the enhancement of natural-protein tolerance and the application of an apparent 'safe' protein to energy ratio to support optimal growth and body composition in PKU.

High protein intake along with paternal part-time employment is associated with higher body fat mass among girls from South China

PURPOSE

Protein intake has been suggested to be associated with body composition among western children. Our aim was to determine whether protein intake is associated with body composition among Chinese children and to investigate whether parental socioeconomic status modifies these associations.

METHODS

Cross-sectional data were collected from the baseline survey of an ongoing population-based prospective open cohort study conducted in 2013. In this survey, 2039 children in South China were recruited using cluster random sampling. Information of 1704 children (47% girls), aged 7-12 years from three primary schools (42 classes), on diet and anthropometry was included finally. Their daily protein intake was obtained by 3-day 24-h dietary recalls. Skinfold thickness, body height, and weight were measured to calculate percent body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental characteristics were collected by questionnaires.

RESULTS

Among girls, protein intake was positively associated with %BF and FMI [estimate (SE) for %BF: 0.007 (0.003), p = 0.04; for FMI: 0.092 (0.002), p = 0.03], adjusted for pubertal stage, breast-feeding, maternal overweight, carbohydrate intake, energy intake, and physical activity level. Furthermore, there was interaction between paternal occupation and the relations of dietary protein with %BF and FMI (p _{for interaction} ≤ 0.04). None of the associations between protein intake and %BF, FMI, or FFMI was found among boys.

CONCLUSIONS

Our data indicate that school-aged girls, but not boys, living in South China with higher dietary protein intake might have higher body fat mass, which could be modified by paternal occupation.

Is the pattern of dietary amino acids intake associated with serum lipid profile and blood pressure among individuals with spinal cord injury?

OBJECTIVE

The probable effect of dietary amino acids intake pattern on serum lipid profile and blood pressure (BP) have not yet been described among individuals with spinal cord injury (SCI).

DESIGN

Cross-sectional.

SETTING

Tertiary rehabilitation center.

PARTICIPANTS

People with SCI referred to Brain and Spinal Cord Injury Research Center between 2011 and 2014.

OUTCOME MEASURES

Dietary intakes were assessed by recording consumed foods by 24-hour dietary recall interviews using Nutritionist IV 3.5.3 modified for Iranian foods. Partial correlation test with adjustment for age, weight, body mass index, total energy intake, total fat, cholesterol and carbohydrate intake, and injury-related variables was used.

RESULTS

Dietary intake of lysine was positively related to levels of fasting plasma glucose (FPG), triglyceride (TG), systolic blood pressure (SBP) and diastolic blood pressure (DBP) (P < 0.0001, 0.046, 0.002 and 0.009, respectively). There was a positive significant relationship between the intake of cysteine and levels of TG and SBP as well (P : 0.027 and 0.048, respectively). Higher intakes of threonine and leucine had a negative relationship with TG level (P : 0.001 and 0.026, respectively). Furthermore, tyrosine, threonine and leucine were inversely correlated to blood pressure. Total cholesterol level was only related to intake of threonine and leucine (P : 0.004 and 0.012, respectively). FPG was positively associated with intake of all amino acids except for cysteine, glutamic acid, threonine, leucine and histidine.

CONCLUSION

In the present study, the pattern of relationships between dietary intake of amino acids and serum lipid profile and BP has been described among people with SCI.

Vitamin D supplementation trial in infancy: body composition effects at 3 years of age in a prospective follow-up study from Montréal

BACKGROUND

The impact of vitamin D status on body composition is not well understood.

OBJECTIVES

Evaluate how vitamin D supplementation in infancy affects body composition at 3 years of age.

METHODS

Double-blind randomized trial of 132, 1-month-old healthy, breastfed infants randomly assigned to receive oral vitamin D₃ supplements of 400, 800, 1200 or 1600 IU d^-1 for 11 months. In the present analysis, 87 (66%) returned at 3 years of age. Body composition was measured using dual-energy x-ray absorptiometry and plasma 25-hydroxyvitamin D [25(OH)D] concentrations by liquid chromatography tandem mass spectrometry.

RESULTS

Anthropometry, body composition, diet, activity and demographics were similar across dosage groups at 3 years. Mean 25(OH)D concentration from 1 month to 3 years was higher (P < 0.001) in the 1200 IU group than 800 and 400 IU groups. Children with 25(OH)D concentrations above 75 nmol L^-1 had lower fat mass (~450 g; P = 0.049). In multiple linear regression, mean 25(OH)D was associated with lean mass percent (β = 0.06; CI: 0.00, 0.12; P = 0.042), fat mass (β = -11.29; CI: -22.06, -0.52; P = 0.048) and body fat percent (β = -0.06; CI: -0.12, -0.01; P = 0.045).

CONCLUSIONS

Higher vitamin D status from infancy through to 3 years of age associates with leaner body composition.

Prospective associations of meat consumption during childhood with measures of body composition during adolescence: results from the GINIplus and LISAplus birth cohorts

BACKGROUND

Higher meat and protein intakes have been associated with increased body weight in adults, but studies evaluating body composition are scarce. Furthermore, our knowledge in adolescents is limited. This study aimed to investigate the prospective associations of intakes of different meat types, and their respective protein contents during childhood, with body composition during adolescence.

METHODS

Dietary (using food frequency questionnaires) and body composition (measured by bioelectrical impedance) data were collected from the 10- and 15-year follow-up assessments respectively, of the GINIplus and LISAplus birth cohort studies. Sex-stratified prospective associations of meat and meat protein intakes (total, processed, red meat and poultry) with fat mass index (FMI) and fat free mass index (FFMI), were assessed by linear regression models (N = 1610).

RESULTS

Among males, higher poultry intakes at age 10 years were associated with a higher FMI at age 15 years [β = 0.278 (SE = 0.139), p = 0.046]; while higher intakes of total and red meat were prospectively associated with higher FFMI [0.386 (0.143), p = 0.007, and 0.333 (0.145), p = 0.022, respectively]. Additionally in males, protein was associated with FFMI for total and red meat [0.285 (0.145) and 0.356 (0.144), respectively].

CONCLUSIONS

Prospective associations of meat consumption with subsequent body composition in adolescents may differ by sex and meat source.

Dietary animal and plant protein intakes and their associations with obesity and cardio-metabolic indicators in European adolescents: the HELENA cross-sectional study

Background

Previous studies suggest that dietary protein might play a beneficial role in combating obesity and its related chronic diseases. Total, animal and plant protein intakes and their associations with anthropometry and serum biomarkers in European adolescents using one standardised methodology across European countries are not well documented.

Objectives

To evaluate total, animal and plant protein intakes in European adolescents stratified by gender and age, and to investigate their associations with cardio-metabolic indicators (anthropometry and biomarkers).

Methods

The current analysis included 1804 randomly selected adolescents participating in the HELENA study (conducted in 2006–2007) aged 12.5-17.5 y (47% males) who completed two non-consecutive computerised 24-h dietary recalls. Associations between animal and plant protein intakes, and anthropometry and serum biomarkers were examined with General linear Model multivariate analysis.

Results

Average total protein intake exceeded the recommendations of World Health Organization and European Food Safety Authority. Mean total protein intake was 96 g/d (59% derived from animal protein). Total, animal and plant protein intakes (g/d) were significantly lower in females than in males and total and plant protein intakes were lower in younger participants (12.5-14.9 y). Protein intake was significantly lower in underweight subjects and higher in obese ones; the direction of the relationship was reversed after adjustments for body weight (g/(kg.d)). The inverse association of plant protein intakes was stronger with BMI z-score and body fat percentage (BF%) compared to animal protein intakes. Additionally, BMI and BF% were positively associated with energy percentage of animal protein.

Conclusions

This sample of European adolescents appeared to have adequate total protein intake. Our findings suggest that plant protein intakes may play a role in preventing obesity among European adolescents. Further longitudinal studies are needed to investigate the potential beneficial effects observed in this study in the prevention of obesity and related chronic diseases.

Nutritional influences over the life course on lean body mass of individuals in developing countries

The double burden of childhood undernutrition and adult-onset adiposity in transitioning societies poses a significant public health challenge. The development of suboptimal lean body mass (LBM) could partly explain the link between these two forms of malnutrition. This review examines the evidence on both the role of nutrition in “developmental programming” of LBM and the nutritional influences that affect LBM throughout the life course. Studies from developing countries assessing the relationship of early nutrition with later LBM provide important insights. Overall, the evidence is consistent in suggesting a positive association of early nutritional status (indicated by birth weight and growth during first 2 years) with LBM in later life. Evidence on the impact of maternal nutritional supplementation during pregnancy on later LBM is inconsistent. In addition, the role of nutrients (protein, zinc, calcium, vitamin D) that can affect LBM throughout the life course is described. Promoting optimal intakes of these important nutrients throughout the life course is important for reducing childhood undernutrition as well as for improving the LBM of adults.

The role of dietary fat on the association between dietary amino acids and serum lipid profile in European adolescents participating in the HELENA Study

BACKGROUND/OBJECTIVES

The objective of this study was to examine the relationship between amino acid (AA) intake and serum lipid profile in European adolescents from eight European cities participating in the cross-sectional (2006-2007) HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study, and to assess whether this association was independent of total fat intake.

SUBJECTS/METHODS

Diet, skinfold thickness, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), TC/HDL-c ratio, low-density lipoprotein cholesterol (LDL-c), apolipoprotein B (Apo B), apolipoprotein A1 (Apo A1) and Apo B/Apo A1 ratio were measured in 454 12.5- to 17.5-year-old adolescents (44% boys). Intake was assessed via two non-consecutive 24-h dietary recalls. Data on maternal education and sedentary behaviors were obtained via questionnaires. Physical activity was objectively measured by accelerometry.

RESULTS

Alanine, arginine, asparaginic acid, glycine, histidine, lysine and serine intakes were inversely associated with serum TG concentrations in both boys and girls. Intake of other AA like alanine and/or arginine was also inversely associated with serum TC, LDL-c and Apo B/Apo A1 ratio only in girls. An inverse association was observed between intakes of alanine, isoleucine, leucine, methionine, serine, tryptophan, tyrosine and valine and TC/HDL-c ratio among female adolescents. Similar results were found in males for serine and tryptophan intakes. It is noteworthy, however, that associations were no longer significant in both genders when total fat intake was considered as a confounding factor.

CONCLUSIONS

In this sample of adolescents, the association between AA intakes and serum lipid profile did not persist when dietary fat was considered. Therefore, dietary interventions and health promotion activities should focus on fat intake to improve lipid profile and potentially prevent cardiovascular disease.

Protein diets, body weight loss and weight maintenance

PURPOSE OF REVIEW

The review addresses briefly the relevance of protein diets for body weight loss and weight maintenance. The addition of recent findings on age-dependent protein requirements, specific effects of protein intake and protein source, the relevance of the other dietary macronutrients, especially of 'low-carb', 'protein leverage', the mechanisms of protein-induced satiety, and food-reward makes the review up-to-date.

RECENT FINDINGS

Different effects of protein diets in different age groups result from age-dependent protein requirements that are primarily related to effects on body composition. A protein intake of 0.8 g/kg/day is sufficient to sustain a negative energy balance in adults, irrespective of the protein source. 'Low-carb' diets trace back to the protein-induced effects. Evidence that protein intake drives energy intake as suggested by the 'Protein leverage hypothesis' is scarce and equivocal. Finally, limited protein-induced food reward may affect compliance to a protein diet.

SUMMARY

An implication of the findings for clinical practice is that a protein intake of 0.8-1.2 g/kg/day is sufficient to sustain satiety, energy expenditure, and fat-free mass, independent of a dietary 'low-carb' content. Limited protein-induced food reward may affect compliance to a protein diet.

Prospective association of protein intake during puberty with body composition in young adulthood

OBJECTIVE

To examine the association of habitual animal and plant protein intake during the potentially critical period of puberty with body composition in young adulthood.

DESIGN AND METHODS

Multivariable regression analyses were performed on data from 140 female and 122 male participants of the DONALD Study with ≥2 3-day weighed dietary records during puberty (girls 9-14 years; boys 10-15 years) and anthropometric measurements in young adulthood (18-25 years). Fat-free mass index (FFMI) and fat mass index (FMI) were estimated from four skinfolds.

RESULTS

In women, a higher pubertal animal protein consumption was independently related to higher levels of FFMI (ptrend = 0.001), but not to FMI (ptrend = 0.5). Adjusted means of FFMI in energy-adjusted tertiles of animal protein intake were 15.3 (95% confidence interval: 15.0, 15.5), 15.4 (15.1, 15.7), 16.2 (15.9, 16.6) kg/m(2) . In men, a higher animal protein intake was related to a higher FFMI (ptrend = 0.04) and a lower FMI (ptrend = 0.001) only after adjusting FFMI for current FMI levels and vice versa. Plant protein was not associated with body composition among either sex.

CONCLUSIONS

Our results show that a higher pubertal animal protein consumption may yield a higher fat-free mass in young adulthood.

Protein intake from 0 to 18 years of age and its relation to health: a systematic literature review for the 5th Nordic Nutrition Recommendations

The present systematic literature review is a part of the 5th revision of the Nordic Nutrition Recommendations. The aim was to assess the health effects of different levels of protein intake in infancy and childhood in a Nordic setting. The initial literature search resulted in 435 abstracts, and 219 papers were identified as potentially relevant. Full paper selection resulted in 37 quality-assessed papers (4A, 30B, and 3C). A complementary search found four additional papers (all graded B). The evidence was classified as convincing, probable, limited-suggestive, and limited-inconclusive. Higher protein intake in infancy and early childhood is convincingly associated with increased growth and higher body mass index in childhood. The first 2 years of life is likely most sensitive to high protein intake. Protein intake between 15 E% and 20 E% in early childhood has been associated with an increased risk of being overweight later in life, but the exact level of protein intake above which there is an increased risk for being overweight later in life is yet to be established. Increased intake of animal protein in childhood is probably related to earlier puberty. There was limited-suggestive evidence that intake of animal protein, especially from dairy, has a stronger association with growth than vegetable protein. The evidence was limited-suggestive for a positive association between total protein intake and bone mineral content and/or other bone variables in childhood and adolescence. Regarding other outcomes, there were too few published studies to enable any conclusions. In conclusion, the intake of protein among children in the Nordic countries is high and may contribute to increased risk of later obesity. The upper level of a healthy intake is yet to be firmly established. In the meantime, we suggest a mean intake of 15 E% as an upper limit of recommended intake at 12 months, as a higher intake may contribute to increased risk for later obesity.

Assessment of protein adequacy in developing countries: quality matters

Dietary protein and amino acid requirement recommendations for normal "healthy" children and adults have varied considerably with 2007 FAO/WHO protein requirement estimates for children lower, but dietary essential AA requirements for adults more than doubled. Requirement estimates as presented do not account for common living conditions, which are prevalent in developing countries such as energy deficit, infection burden and added functional demands for protein and AAs. This study examined the effect of adjusting total dietary protein for quality and digestibility (PDCAAS) and of correcting current protein and AA requirements for the effect of infection and a mild energy deficit to estimate utilizable protein (total protein corrected for biological value and digestibility) and the risk/prevalence of protein inadequacy. The relationship between utilizable protein/prevalence of protein inadequacy and stunting across regions and countries was examined. Data sources (n = 116 countries) included FAO FBS (food supply), UNICEF (stunting prevalence), UNDP (GDP) and UNSTATS (IMR) and USDA nutrient tables. Statistical analyses included Pearson correlations, paired-sample/non-parametric t-tests and linear regression. Statistically significant differences were observed in risk/prevalence estimates of protein inadequacy using total protein and the current protein requirements versus utilizable protein and the adjusted protein requirements for all regions (p < 0·05). Total protein, utilizable protein, GDP per capita and total energy were each highly correlated with the prevalence of stunting. Energy, protein and utilizable protein availability were independently and negatively associated with stunting (p < 0·001), explaining 41 %, 34 % and 40 % of variation respectively. Controlling for energy, total protein was not a statistically significant factor but utilizable protein remained significant explaining~45 % of the variance (p = 0·017). Dietary utilizable protein provides a better index of population impact of risk/prevalence of protein inadequacy than crude protein intake. We conclude that the increased demand for protein due to infections and mild to moderate energy deficits, should be appropriately considered in assessing needs of populations where those conditions still prevail.

Regulation of brown adipose tissue development and white fat reduction by L-arginine

PURPOSE OF REVIEW

Brown adipose tissue (BAT), which is present in humans, plays an important role in oxidation of fatty acids and glucose. The purpose of this review is to highlight an important role for L-arginine in regulating BAT growth and development, thereby reducing obesity in mammals.

RECENT FINDINGS

Dietary supplementation with L-arginine reduces white adipose tissue in genetically or diet-induced obese rats, obese pregnant sheep, and obese humans with type II diabetes. L-arginine treatment enhances BAT growth in both fetuses and postnatal animals. At molecular and cellular levels, L-arginine stimulates expression of peroxisome proliferator-activated receptor-γ coactivator 1 (the master regulator of mitochondrial biogenesis), nitric oxide synthase, heme oxygenase, and adenosine monophosphate-activated protein kinase. At the whole body level, L-arginine increases blood flow to insulin-sensitive tissues, adipose tissue lipolysis, and the catabolism of glucose and fatty acids, but inhibits fatty acid synthesis and ameliorates oxidative stress, thereby improving metabolic profile.

SUMMARY

L-arginine increases mammalian BAT growth and development via mechanisms involving gene expression, nitric oxide signaling, and protein synthesis. This enhances the oxidation of energy substrates and, thus, reduces white fat accretion in the body. L-arginine holds great promise in preventing and treating obesity in humans.

The search for compounds that stimulate thermogenesis in obesity management: from pharmaceuticals to functional food ingredients

The concept of managing obesity through the stimulation of thermogenesis is currently a focus of considerable attention by the pharmaceutical, nutraceutical and functional food industries. This paper first reviews the landmark discoveries that have fuelled the search for thermogenic anti-obesity products that range from single-target drugs to multi-target functional foods. It subsequently analyses the thermogenic and fat-oxidizing potentials of a wide array of bioactive food ingredients which are categorized under methylxanthines, polyphenols, capsaicinoids/capsinoids, minerals, proteins/amino acids, carbohydrates/sugars and fats/fatty acids. The main outcome of this analysis is that the compounds or combination of compounds with thermogenic and fat-oxidizing potentials are those that possess both sympathomimetic stimulatory activity and acetyl-coA carboxylase inhibitory property, and are capable of targeting both skeletal muscle and brown adipose tissue. The thermogenic potentials of products so far tested in humans range from marginal to modest, i.e. 2-5% above daily energy expenditure. With an increasing number of bioactive food ingredients awaiting screening in humans, there is hope that this thermogenic potential could be safely increased to 10-15% above daily energy expenditure - which would have clinically significant impact on weight management, particularly in the prevention of obesity and in improving the long-term prognosis of post-slimming weight maintenance.

Role of dietary factors and food habits in the development of childhood obesity: a commentary by the ESPGHAN Committee on Nutrition

This Comment by the Committee on Nutrition of the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition aims to provide a summary of the role of nutrition-related factors on obesity prevention in children ages 2 to 18 years. This Comment emphasizes that dietary interventions should be incorporated into a multidisciplinary strategy for obesity prevention. No single nutrient has been unequivocally associated with the development of obesity. Methodological limitations in study design and the complex nature of obesity must be taken into account when interpreting the association with reported dietary factors. Energy intake should be individually determined, taking into account energy expenditure and growth. Preferential intake of slowly absorbed carbohydrates and limiting the ingestion of rapidly absorbed carbohydrates and simple sugars should be promoted. No specific recommendations for macronutrient intakes to prevent obesity can be made. Plant foods can be used as the main food contributors to a well-balanced diet with adequate monitoring of nutrient intake. Plain water should be promoted as the main source of fluids for children instead of sugar-sweetened beverages. Children should eat at least 4 meals, including breakfast, every day. Regular family meals should be encouraged. Regular consumption of fast food with large portion sizes and high energy density should be avoided. Healthy food options should be promoted for snacking. Food portion sizes should be appropriate for age and body size. Nutrition and lifestyle education aimed at the prevention of obesity should be included in the routine care of children by health care professionals.

Effect of lysine supplementation on health and morbidity in subjects belonging to poor peri-urban households in Accra, Ghana

BACKGROUND

Lysine affects diarrhea and anxiety via effects on serotonin receptors, enhanced intestinal repair, and sodium chloride-dependent opioid peptide transport.

OBJECTIVE

The objective was to investigate the effects of lysine supplementation on morbidity, growth, and anxiety in children and adults of peri-urban areas of Accra, Ghana.

DESIGN

In a double-blind randomized trial, the effect of lysine supplementation (1 g lysine/d) compared with that of placebo was examined in 2 groups of men, women, and children (n = 271). Primary outcomes included diarrheal and respiratory morbidity, growth, and anxiety and complement C3, C-reactive protein, serum cortisol, transferrin, and ferritin values. Independent-sample t tests, odds ratios, generalized estimating equations, 4-parameter sinusoid regression, and generalized linear models were used.

RESULTS

Thirty percent of men, 50% of women, and 15% of children were at risk of lysine inadequacy. Supplementation in children reduced diarrheal episodes [19 lysine, 35 placebo; odds ratio (OR): 0.52; 95% CI: 0.29, 0.92; P = 0.046] and the total number of days ill (21 lysine, 47 placebo; OR: 0.44; 95% CI: 0.26, 0.74; P = 0.034). Mean days ill per child per week (0.058 ± 0.039 lysine, 0.132 ± 0.063 placebo; P = 0.017) were negatively associated with weight gain with control for baseline weight and study group (P = 0.04). Men had fewer coryza episodes (23 lysine, 39 placebo; OR: 0.60; 95% CI: 0.36, 1.01; P = 0.05), total number of days ill (lysine: 130; placebo: 266; OR: 0.51; 95% CI: 0.28, 0.93; P = 0.03), and mean days ill per person per week (lysine: 0.21 ± 0.23; placebo: 0.41 ± 0.35; P = 0.04). Serum ferritin (P = 0.045) and C-reactive protein (P = 0.018) decreased in lysine-supplemented women but increased in placebo-supplemented women.

CONCLUSION

Lysine supplementation reduced diarrheal morbidity in children and respiratory morbidity in men in Ghana.