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International Archives of Allergy and... 2023Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food-induced hypersensitivity disorder that occurs mostly in infants. Long... (Meta-Analysis)
Meta-Analysis
Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food-induced hypersensitivity disorder that occurs mostly in infants. Long considered a rare disease, a recent increase in physician awareness and publication of diagnosis of guidelines has resulted in an increase in recognized FPIES cases. We aimed to conduct a systematic review of FPIES studies in the past 10 years. A search was conducted on PubMed and Embase in March 2022. Our systematic review focused on 2 domains: (1) the most reported FPIES food triggers; and (2) the resolution rate and median age at resolution of patients with FPIES. We found that cow's milk was the most reported trigger globally. Patterns of the most common triggers varied by country, with fish being one of the most common triggers in the Mediterranean region. We also found that the rate and median age of resolution varied by trigger. Patients with FPIES to cow's milk acquired tolerance at a younger age (most by age 3 years), while fish-FPIES was more persistent (mean resolution by age 37 months-7 years). Overall, many studies found a resolution rate of 60% for any food.
Topics: Female; Animals; Cattle; Food Hypersensitivity; Milk; Enterocolitis; Allergens; Syndrome; Dietary Proteins
PubMed: 36882041
DOI: 10.1159/000529138 -
The American Journal of Gastroenterology Jun 2015Persistent disease activity is associated with a poor prognosis in inflammatory bowel disease (IBD). Therefore, monitoring of patients with intent to suppress... (Meta-Analysis)
Meta-Analysis Review
C-Reactive Protein, Fecal Calprotectin, and Stool Lactoferrin for Detection of Endoscopic Activity in Symptomatic Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis.
OBJECTIVES
Persistent disease activity is associated with a poor prognosis in inflammatory bowel disease (IBD). Therefore, monitoring of patients with intent to suppress subclinical inflammation has emerged as a treatment concept. As endoscopic monitoring is invasive and resource intensive, identification of valid markers of disease activity is a priority. The objective was to evaluate the diagnostic accuracy of C-reactive protein (CRP), fecal calprotectin (FC), and stool lactoferrin (SL) for assessment of endoscopically defined disease activity in IBD.
METHODS
Databases were searched from inception to November 6, 2014 for relevant cohort and case-control studies that evaluated the diagnostic accuracy of CRP, FC, or SL and used endoscopy as a gold standard in patients with symptoms consistent with active IBD. Sensitivities and specificities were pooled to generate operating property estimates for each test using a bivariate diagnostic meta-analysis.
RESULTS
Nineteen studies (n=2499 patients) were eligible. The pooled sensitivity and specificity estimates for CRP, FC, and SL were 0.49 (95% confidence interval (CI) 0.34-0.64) and 0.92 (95% CI 0.72-0.96), 0.88 (95% CI 0.84-0.90) and 0.73 (95% CI 0.66-0.79), and 0.82 (95% CI 0.73-0.88) and 0.79 (95% CI 0.62-0.89), respectively. FC was more sensitive than CRP in both diseases and was more sensitive in ulcerative colitis than Crohn's disease.
CONCLUSIONS
Although CRP, FC, and SL are useful biomarkers, their value in managing individual patients must be considered in specific clinical contexts.
Topics: Biomarkers; C-Reactive Protein; Colitis, Ulcerative; Crohn Disease; Endoscopy, Gastrointestinal; Feces; Humans; Lactoferrin; Leukocyte L1 Antigen Complex; Sensitivity and Specificity
PubMed: 25964225
DOI: 10.1038/ajg.2015.120 -
PloS One 2018Dietary protein restriction has long been thought to play an important role in the progression of chronic kidney disease (CKD); however, the effect of dietary protein on... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Dietary protein restriction has long been thought to play an important role in the progression of chronic kidney disease (CKD); however, the effect of dietary protein on the rate of decline in kidney function remains controversial.
OBJECTIVE
We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the influence of protein restriction on chronic kidney disease.
METHOD
Ovid MEDLINE (from 1946 to March 5, 2016), EMBASE (from 1966 to March 5, 2016), and the Cochrane Library (Inception to March 5, 2016) were searched to identify RCTs comparing different levels of protein intake for at least 24 weeks in adult patients with CKD. The outcomes included kidney failure events, the rate of change in estimated glomerular filtration rate (eGFR) per year, all cause death events, and changes in proteinuria, serum phosphorus concentration, serum albumin, and body mass index (BMI).
RESULTS
Nineteen trials with 2492 subjects were analyzed. A low protein diet reduced the risk of kidney failure (odds ratio (OR) = 0.59, 95% CI: 0.41 to 0.85) and end-stage renal disease (ESRD) (OR = 0.64, 95% CI: 0.43 to 0.96), but did not produce a clear beneficial effect for all cause death events (OR = 1.17, 95% CI: 0.67 to 2.06). The change in the mean difference (MD) for the rate of decline in the eGFR was significant (MD: -1.85, P = 0.001), and for proteinuria (MD: -0.44, P = 0.02). A low protein diet also reduced the serum phosphorus concentration (MD: -0.37, 95% CI: -0.5 to -0.24) and BMI (MD: -0.61, 95% CI: -1.05 to -0.17). However the change in albumin presented no significant difference between two groups (MD: 0.23, 95% CI: -0.51 to 0.97).
CONCLUSIONS
Based on the findings of our meta-analysis, protein-restricted diet may reduce the rate of decline in renal function and the risk of kidney failure for CKD populations, but did not produce a clear beneficial effect for all cause death events. Besides However, the optimal level of protein intake in different participants is left unanswered, and the nutritional status should be regarded with caution.
Topics: Adult; Aged; Cause of Death; Clinical Trials as Topic; Diet, Protein-Restricted; Disease Progression; Female; Glomerular Filtration Rate; Humans; Kidney; Kidney Failure, Chronic; Male; Middle Aged; Phosphorus; Proteinuria; Renal Insufficiency, Chronic; Treatment Outcome
PubMed: 30403710
DOI: 10.1371/journal.pone.0206134 -
Journal of Cachexia, Sarcopenia and... Apr 2018Recent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low-protein diet can be a safe and effective means to avoid... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Recent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low-protein diet can be a safe and effective means to avoid or defer transition to dialysis therapy without causing protein-energy wasting or cachexia. We aimed to systematically review and meta-analyse the controlled clinical trials with adequate participants in each trial, providing rigorous contemporary evidence of the impact of a low-protein diet in the management of uraemia and its complications in patients with CKD.
METHODS
We searched MEDLINE (PubMed) and other sources for controlled trials on CKD to compare clinical management of CKD patients under various levels of dietary protein intake or to compare restricted protein intake with other interventions. Studies with similar patients, interventions, and outcomes were included in the meta-analyses.
RESULTS
We identified 16 controlled trials of low-protein diet in CKD that met the stringent qualification criteria including having 30 or more participants. Compared with diets with protein intake of >0.8 g/kg/day, diets with restricted protein intake (<0.8 g/kg/day) were associated with higher serum bicarbonate levels, lower phosphorus levels, lower azotemia, lower rates of progression to end-stage renal disease, and a trend towards lower rates of all-cause death. In addition, very-low-protein diets (protein intake <0.4 g/kg/day) were associated with greater preservation of kidney function and reduction in the rate of progression to end-stage renal disease. Safety and adherence to a low-protein diet was not inferior to a normal protein diet, and there was no difference in the rate of malnutrition or protein-energy wasting.
CONCLUSIONS
In this pooled analysis of moderate-size controlled trials, a low-protein diet appears to enhance the conservative management of non-dialysis-dependent CKD and may be considered as a potential option for CKD patients who wish to avoid or defer dialysis initiation and to slow down the progression of CKD, while the risk of protein-energy wasting and cachexia remains minimal.
Topics: Diet, Protein-Restricted; Disease Progression; Humans; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic
PubMed: 29094800
DOI: 10.1002/jcsm.12264 -
The Cochrane Database of Systematic... Oct 2018Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. This condition... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. This condition appears to be more frequent in the first six weeks of life (prevalence range of 17% to 25%), depending on the specific location reported and definitions used, and it usually resolves by three months of age. The aetiopathogenesis of infantile colic is unclear but most likely multifactorial. A number of psychological, behavioural and biological components (food hypersensitivity, allergy or both; gut microflora and dysmotility) are thought to contribute to its manifestation. The role of diet as a component in infantile colic remains controversial.
OBJECTIVES
To assess the effects of dietary modifications for reducing colic in infants less than four months of age.
SEARCH METHODS
In July 2018 we searched CENTRAL, MEDLINE, Embase , 17 other databases and 2 trials registers. We also searched Google, checked and handsearched references and contacted study authors.
SELECTION CRITERIA
Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of dietary modifications, alone or in combination, for colicky infants younger than four months of age versus another intervention or placebo. We used specific definitions for colic, age of onset and the methods for performing the intervention. We defined 'modified diet' as any diet altered to include or exclude certain components.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Our primary outcome was duration of crying, and secondary outcomes were response to intervention, frequency of crying episodes, parental/family quality of life, infant sleep duration, parental satisfaction and adverse effects.
MAIN RESULTS
We included 15 RCTs involving 1121 infants (balanced numbers of boys and girls) aged 2 to 16 weeks. All studies were small and at high risk of bias across multiple design factors (e.g. selection, attrition). The studies covered a wide range of dietary interventions, and there was limited scope for meta-analysis. Using the GRADE approach, we assessed the quality of the evidence as very low.Low-allergen maternal diet versus a diet containing known potential allergens: one study (90 infants) found that 35/47 (74%) of infants responded to a low-allergen maternal diet, compared with 16/43 (37%) of infants on a diet containing known potential allergens.Low-allergen diet or soy milk formula versus dicyclomine hydrochloride: one study (120 infants) found that 10/15 (66.6%) breastfed babies responded to dicyclomine hydrochloride, compared with 24/45 (53.3%) formula-fed babies. There was little difference in response between breastfed babies whose mother changed their diet (10/16; 62.5%) and babies who received soy milk formula (29/44; 65.9%).Hydrolysed formula versus standard formula: two studies (64 infants) found no difference in duration of crying, reported as a dichotomous outcome: risk ratio 2.03, 95% confidence interval (CI) 0.81 to 5.10; very low-quality evidence. The author of one study confirmed there were no adverse effects. One study (43 infants) reported a greater reduction in crying time postintervention with hydrolysed formula (104 min/d, 95% CI 55 to 155) than with standard formula (3 min/d, 95% CI -63 to 67).Hydrolysed formula versus another hydrolysed formula: one study (22 infants) found that two types of hydrolysed formula were equally effective in resolving symptoms for babies who commenced with standard formula (Alimentum reduced crying to 2.21 h/d (standard deviation (SD) 0.40) and Nutramigen to 2.93 h/d (SD 0.70)).Hydrolysed formula or dairy- and soy-free maternal diet versus addition of parental education or counselling: one study (21 infants) found that crying time decreased to 2.03 h/d (SD 1.03) in the hydrolysed or dairy- and soy-free group compared with 1.08 h/d (SD 0.7) in the parent education or counselling group, nine days into the intervention.Partially hydrolysed, lower lactose, whey-based formulae containing oligosaccharide versus standard formula with simethicone: one study (267 infants) found that both groups experienced a decrease in colic episodes (secondary outcome) after seven days (partially hydrolysed formula: from 5.99 episodes (SD 1.84) to 2.47 episodes (SD 1.94); standard formula: from 5.41 episodes (SD 1.88) to 3.72 episodes (SD 1.98)). After two weeks the difference between the two groups was significant (partially hydrolysed: 1.76 episodes (SD 1.60); standard formula: 3.32 episodes (SD 2.06)). The study author confirmed there were no adverse effects.Lactase enzyme supplementation versus placebo: three studies (138 infants) assessed this comparison, but none reported data amenable to analysis for any outcome. There were no adverse effects in any of the studies.Extract of Foeniculum vulgare, Matricariae recutita, and Melissa officinalis versus placebo: one study (93 infants) found that average daily crying time was lower for infants given the extract (76.9 min/d (SD 23.5), than infants given placebo (169.9 min/d (SD 23.1), at the end of the one-week study. There were no adverse effects.Soy protein-based formula versus standard cows' milk protein-based formula: one study (19 infants) reported a mean crying time of 12.7 h/week (SD 16.4) in the soy formula group versus 17.3 h/week (SD 6.9) in the standard cows' milk group, and that 5/10 (50%) responded in the soy formula group versus 0/9 (0%) in the standard cows' milk group.Soy protein formula with polysaccharide versus standard soy protein formula: one study (27 infants) assessed this comparison but did not provide disaggregated data for the number of responders in each group after treatment.No study reported on our secondary outcomes of parental or family quality of life, infant sleep duration per 24 h, or parental satisfaction.
AUTHORS' CONCLUSIONS
Currently, evidence of the effectiveness of dietary modifications for the treatment of infantile colic is sparse and at significant risk of bias. The few available studies had small sample sizes, and most had serious limitations. There were insufficient studies, thus limiting the use of meta-analysis. Benefits reported for hydrolysed formulas were inconsistent.Based on available evidence, we are unable to recommend any intervention. Future studies of single interventions, using clinically significant outcome measures, and appropriate design and power are needed.
Topics: Allergens; Colic; Crying; Diet Therapy; Female; Humans; Infant; Infant Formula; Lactase; Male; Randomized Controlled Trials as Topic; Soybean Proteins; Time Factors
PubMed: 30306546
DOI: 10.1002/14651858.CD011029.pub2 -
Nutrients Sep 2021The primary aim was to systematically review the current evidence investigating if dietary interventions rich in protein lead to improved body weight management in... (Meta-Analysis)
Meta-Analysis
Are Dietary Proteins the Key to Successful Body Weight Management? A Systematic Review and Meta-Analysis of Studies Assessing Body Weight Outcomes after Interventions with Increased Dietary Protein.
The primary aim was to systematically review the current evidence investigating if dietary interventions rich in protein lead to improved body weight management in adults with excessive body weight. The secondary aim was to investigate potential modifying effects of phenotyping. A systematic literature search in PubMed, Web of Science, and Cochrane Library identified 375 randomized controlled trials with 43 unique trials meeting the inclusion criteria. The Cochrane collaboration tool was used for a thorough risk of bias assessment. Based on 37 studies evaluating effects of dietary protein on body weight, the participants with increased protein intake (ranging from 18-59 energy percentage [E%]) were found to reduce body weight by 1.6 (1.2; 2.0) kg (mean [95% confidence interval]) compared to controls (isocaloric interventions with energy reduction introduced in certain studies). Individuals with prediabetes were found to benefit more from a diet high in protein compared to individuals with normoglycemia, as did individuals without the obesity risk allele (AA genotype) compared to individuals with the obesity risk alleles (AG and GG genotypes). Thus, diets rich in protein would seem to have a moderate beneficial effect on body weight management.
Topics: Adult; Body Mass Index; Body Weight; Diet, High-Protein; Dietary Proteins; Exercise; Female; Humans; Male; Middle Aged; Obesity; Overweight; Randomized Controlled Trials as Topic; Weight Gain; Weight Loss; Young Adult
PubMed: 34579069
DOI: 10.3390/nu13093193 -
The Cochrane Database of Systematic... Aug 2020Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.
OBJECTIVES
To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.
SEARCH METHODS
We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.
SELECTION CRITERIA
Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.
MAIN RESULTS
We included 15 randomised controlled trials (RCTs) (16 comparisons, 56,675 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.70 to 0.98, 12 trials, 53,758 participants of whom 8% had a cardiovascular event, I² = 67%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 53. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.
AUTHORS' CONCLUSIONS
The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.
Topics: Adult; Cardiovascular Diseases; Cause of Death; Cholesterol; Dietary Carbohydrates; Dietary Fats; Dietary Fats, Unsaturated; Dietary Proteins; Energy Intake; Fatty Acids; Female; Humans; Male; Myocardial Infarction; Randomized Controlled Trials as Topic; Stroke
PubMed: 32827219
DOI: 10.1002/14651858.CD011737.pub3 -
Nutrients May 2021A disequilibrium of the gut microbial community has been closely associated with systemic inflammation and metabolic syndromes including type 2 diabetes. While low fibre... (Meta-Analysis)
Meta-Analysis
The Effect of Dietary Fibre on Gut Microbiota, Lipid Profile, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
BACKGROUND
A disequilibrium of the gut microbial community has been closely associated with systemic inflammation and metabolic syndromes including type 2 diabetes. While low fibre and high fat diets may lead to dysbiosis of the gut microbiome as a result of the loss of useful microbes, it has been reported that a high fibre diet may prevent the fermentation of protein and may promote eubiosis of gut microbiota.
AIM
This review aims to evaluate the effect of dietary fibre (DF) on gut microbiota, lipid profile, and inflammatory markers in patients with type 2 diabetes.
METHODS
The PRISMA framework was relied on to conduct this systematic review and meta-analysis. Searches were carried out using electronic databases and reference list of articles.
RESULTS
Eleven studies were included in the systematic review, while ten studies were included in the meta-analysis. The findings revealed five distinct areas including the effects of DF on (a) gut microbiota (122 participants); (b) lipopolysaccharides (LPS, 79 participants) and lipopolysaccharides binding protein (LBP, 81 participants); (c) lipid profile; (d) inflammatory markers; and (e) body mass index (BMI, 319 participants). The relative abundance of increased by 0.73 (95% CI: 0.57, 0.89) in the DF group in contrast to the control ( < 0.05). With respect to LPS, the level was lower in the DF group than the control and the difference was significant ( < 0.05). The standardised mean difference for LPS was -0.45 (95% CI: -0.90, -0.01) although the difference between the two groups in relation to LBP was not significant ( = 0.08) and the mean difference was 0.92 (95% CI: -0.12, 1.95). While there was a decrease of -1.05 (95% CI: -2.07, -0.02) with respect to total cholesterol (356 participants) in the DF group as compared with the control ( < 0.05), both groups were not significantly different ( > 0.05) in the other lipid parameters. The difference between the groups was significant ( < 0.05) in relation to C-reactive protein, and the mean difference was 0.43 (95% CI: 0.02, 0.84). This could be due to the short duration of the included studies and differences in participants' diets including the amount of dietary fibre supplements. However, the groups were not significantly different ( > 0.05) with respect to the other inflammatory markers. The meta-analysis of the BMI showed that the DF group decreased by -0.57 (95% CI: -1.02, -0.12) as compared with the control and this was significant ( < 0.01).
CONCLUSION
DF significantly ( < 0.05) increased the relative abundance of and significantly decreased ( < 0.05) LPS, total cholesterol, and BMI as compared with the control. However, DF did not seem to have an effect that was significant on LBP, triglyceride, HDL cholesterol, LDL cholesterol, IL-6, TNF-α, adiponectin, and leptin. These findings have implications for public health in relation to the use of dietary fibre in nutritional interventions and as strategies for managing type 2 diabetes.
Topics: Acute-Phase Proteins; Bifidobacterium; Biomarkers; Body Mass Index; C-Reactive Protein; Carrier Proteins; Databases, Factual; Diabetes Mellitus, Type 2; Dietary Fiber; Dysbiosis; Gastrointestinal Microbiome; Humans; Lipids; Membrane Glycoproteins; Metabolic Syndrome; Randomized Controlled Trials as Topic; Triglycerides
PubMed: 34073366
DOI: 10.3390/nu13061805 -
Nutrients Sep 2019Whey protein (WP) is a dairy food supplement and, due to its effects on fat-free mass (FFM) gain and fat mass (FM) loss, it has been widely consumed by resistance... (Meta-Analysis)
Meta-Analysis
Whey protein (WP) is a dairy food supplement and, due to its effects on fat-free mass (FFM) gain and fat mass (FM) loss, it has been widely consumed by resistance training practitioners. This review analyzed the impact of WP supplementation in its concentrated (WPC), hydrolyzed (WPH) and isolated (WPI) forms, comparing it exclusively to isocaloric placebos. Random effect meta-analyses were performed from the final and initial body composition values of 246 healthy athletes undergoing 64.5 ± 15.3 days of training in eight randomized clinical trials (RCT) collected systematically from five scientific databases. The weighted mean difference (WMD) was statistically significant for FM loss (WMD = -0.96, 95% CI = -1.37, -0.55, < 0.001) and, in the analysis of subgroups, this effect was maintained for the WPC (WMD = -0.63, 95% CI = -1.19, -0.06, = 0.030), with protein content between 51% and 80% (WMD = -1.53; 95% CI = -2.13, -0.93, < 0.001), and only for regular physical activity practitioners (WMD = -0.95; 95% CI = -1.70, -0.19, = 0.014). There was no significant effect on FFM in any of the scenarios investigated ( > 0.05). Due to several and important limitations, more detailed analyses are required regarding FFM gain.
Topics: Athletes; Body Composition; Dietary Supplements; Humans; Whey Proteins
PubMed: 31480653
DOI: 10.3390/nu11092047 -
The Journal of Nutrition Jun 2020Increased protein intake has been suggested to improve gains in muscle mass and strength in adults. Furthermore, the timing of protein intake has been discussed as a... (Meta-Analysis)
Meta-Analysis
The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
BACKGROUND
Increased protein intake has been suggested to improve gains in muscle mass and strength in adults. Furthermore, the timing of protein intake has been discussed as a margin of opportunity for improved prevention measures.
OBJECTIVE
This systematic review investigated the effect of protein supplementation on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake.
METHODS
Randomized controlled trials were identified using PubMed, Web of Science, CINAHL, and Embase, up to March 2019. For meta-analyses, data on lean body mass (LBM), handgrip strength, and leg press strength were pooled by age group (mean age 18-55 or >55 y) and timing of protein intake. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.
RESULTS
Data from 65 studies with 2907 participants (1514 men and 1380 women, 13 unknown sex) were included in the review. Twenty-six, 8, and 24 studies were used for meta-analysis on LBM, handgrip strength, and leg press strength, respectively. The protein supplementation was effective in improving (mean difference; 95% CI) LBM in adults (0.62 kg; 0.36, 0.88) and older adults (0.46 kg; 0.23, 0.70), but not handgrip strength (older adults: 0.26 kg; -0.51, 1.04) and leg press strength (adults: 5.80 kg; -0.33, 11.93; older adults: 1.97 kg; -2.78, 6.72). Sensitivity analyses removing studies without exercise training had no impact on the outcomes. Data regarding muscle synthesis were scarce and inconclusive. Subgroup analyses showed no beneficial effect of a specific timing of protein intake on LBM, handgrip strength, and leg press strength.
CONCLUSION
Overall, the results support the positive impact of protein supplementation on LBM of adults and older adults, independently of intake timing. Effects on muscle strength and synthesis are less clear and need further investigation. This systematic review was registered on PROSPERO as CRD42019126742.
Topics: Adolescent; Adult; Body Composition; Dietary Proteins; Female; Humans; Male; Middle Aged; Muscle, Skeletal; Randomized Controlled Trials as Topic; Resistance Training; Young Adult
PubMed: 32232404
DOI: 10.1093/jn/nxaa049