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Nutrition Research Reviews Dec 2023The rates of dietary protein digestion and absorption can be significantly increased or decreased by food processing treatments such as heating, gelling and enzymatic... (Review)
Review
The rates of dietary protein digestion and absorption can be significantly increased or decreased by food processing treatments such as heating, gelling and enzymatic hydrolysis, with subsequent metabolic impacts, e.g. on muscle synthesis and glucose homeostasis.This review examines evidence that industrial and domestic food processing modify the kinetics of amino acid release and absorption following a protein-rich meal. It focuses on studies that used compositionally-matched test meals processed in different ways.Food processing at extremely high temperature at alkaline pH and/or in the presence of reducing sugars can modify amino acid sidechains, leading to loss of bioavailability. Some protein-rich food ingredients are deliberately aggregated, gelled or hydrolysed during manufacture. Hydrolysis accelerates protein digestion/absorption and increases splanchnic utilisation. Aggregation and gelation may slow or accelerate proteolysis in the gut, depending on the aggregate/gel microstructure.Milk, beef and eggs are heat processed prior to consumption to eliminate pathogens and improve palatability. The temperature and time of heating affect protein digestion and absorption rates, and effects are sometimes non-linear. In light of a dietary transition away from animal proteins, more research is needed on how food processing affects digestion and absorption of non-animal proteins.Food processing modifies the microstructure of protein-rich foods, and thereby alters protein digestion and absorption kinetics in the stomach and small intestine. Exploiting this principle to optimise metabolic outcomes requires more human clinical trials in which amino acid absorption rates are measured and food microstructure is explicitly considered, measured and manipulated.
Topics: Animals; Cattle; Humans; Proteolysis; Digestion; Amino Acids; Dietary Proteins; Food Handling
PubMed: 36522674
DOI: 10.1017/S0954422422000245 -
Nutrients Oct 2023Because the associations between different dietary protein sources and the risks of gestational diabetes mellitus (GDM) are inconsistent, and those of eating habits with...
Because the associations between different dietary protein sources and the risks of gestational diabetes mellitus (GDM) are inconsistent, and those of eating habits with GDM have rarely been explored, we aimed to investigate the independent and joint association of major dietary protein sources and eating habits with GDM in a case-control study including 353 GDM cases and 718 controls in China. Dietary protein intake and eating habits prior to GDM diagnosis were collected through questionnaires at 24~28 gestational weeks. Multivariate logistic regression was used to evaluate the independent and joint associations of dietary protein intake and eating habits with GDM. The Anderson model was used assess if there is an additive interaction between them. Animal protein, red meat protein and dairy products protein intake were significantly and positively associated with GDM. Among the eating habits, preferences for hot food, firm food and soft food were significantly associated with higher odds of GDM. Individuals with unhealthy eating habits and high dietary protein simultaneously had the highest odds of GDM, and the ORs were 2.06 (1.25, 3.41) for the total protein, 2.97 (1.78, 4.96) for animal meat, 3.98 (2.41, 6.57) for the red meat protein and 2.82 (1.81, 4.41) for the dairy protein; the values for the trend were all significant ( < 0.001). However, no additive interaction was detected. In conclusion, our study found that dietary protein intake and eating habits prior to GDM diagnosis were both independently and jointly associated with the odds of GDM.
Topics: Pregnancy; Female; Humans; Diabetes, Gestational; Dietary Proteins; Case-Control Studies; Feeding Behavior; Meat Proteins; Diet; Risk Factors
PubMed: 37892408
DOI: 10.3390/nu15204332 -
The American Journal of Clinical... Jul 2021High-protein diets (e.g., Paleo, Atkins, South Beach, ketogenic) have gained popularity as a means to promote weight loss and avoid excess carbohydrate consumption. Yet...
BACKGROUND
High-protein diets (e.g., Paleo, Atkins, South Beach, ketogenic) have gained popularity as a means to promote weight loss and avoid excess carbohydrate consumption. Yet in chronic kidney disease (CKD) patients, evidence suggests low dietary protein intake (DPI) leads to attenuation of kidney function decline, although concerns remain for risk of protein-energy wasting.
OBJECTIVES
To examine associations of DPI with mortality in a nationally representative cohort of US adults, stratified by kidney function.
METHODS
We examined the association between daily DPI scaled to actual body weight (ABW), ascertained by 24-h dietary recall, with all-cause mortality among 27,604 continuous NHANES adult participants (1999-2010), stratified according to impaired versus normal kidney function (estimated glomerular filtration rates <60 compared with ≥60 ml/min/1.72 m2, respectively), using multivariable Cox models. We also examined the relation between high biological value (HBV) protein consumption with mortality.
RESULTS
In participants with impaired kidney function, a high DPI of ≥1.4 g/kg ABW/day was associated with higher mortality, while lower DPI levels were not associated with mortality (reference, 0.6 to <1.0 g/kg ABW/day): the adjusted HRs (aHRs) were 1.09 (95% CI: 0.90, 1.32), 1.03 (95% CI: 0.82, 1.29), and 1.37 (95% CI: 1.02, 1.85) for DPI <0.6, 1.0 to <1.4, and ≥1.4 g/kg ABW/day, respectively. Yet in participants with normal kidney function, a low DPI of <0.6 g/kg ABW/day was associated with higher mortality, whereas higher DPI levels were not associated with death: the aHRs were 1.18 (95% CI: 1.04, 1.34), 0.92 (95% CI: 0.81, 1.04), and 0.99 (95% CI: 0.85, 1.16) for DPI <0.6, 1.0 to <1.4, and ≥1.4 g/kg ABW/day, respectively. The highest 2 tertiles of HBV consumption were associated with higher mortality in participants with impaired kidney function.
CONCLUSIONS
Among participants with impaired kidney function, a higher DPI and greater HBV consumption were associated with higher mortality, whereas a lower DPI was associated with higher mortality in those with normal kidney function. Further studies are needed to elucidate the specific pathways between higher DPI and mortality in CKD.
Topics: Body Weight; Cohort Studies; Diet Records; Dietary Proteins; Exercise; Glomerular Filtration Rate; Humans; Kidney; Kidney Function Tests; Mortality; Risk Factors; United States
PubMed: 33742197
DOI: 10.1093/ajcn/nqab011 -
Current Nutrition Reports Dec 2019The purpose of this review is to provide background on the present literature regarding the utility and effectiveness of protein supplements, including protein source... (Review)
Review
PURPOSE OF REVIEW
The purpose of this review is to provide background on the present literature regarding the utility and effectiveness of protein supplements, including protein source and nutrient timing.
RECENT FINDINGS
In the setting of adequate dietary protein consumption, research suggests some benefit particularly in sport or exercise activities. Protein supplements command a multi-billion-dollar market with prevalent use in sports. Many individuals, including athletes, do not consume optimal dietary protein on a daily basis. High-protein diets are remarkably safe in healthy subjects, especially in the short term. Some objective outcomes are physiologic and may not translate to clinically relevant outcomes. Athletes should, however, consider long-term implications when consuming high quantities of protein in dietary or supplement form.
Topics: Athletes; Athletic Performance; Body Composition; Databases, Factual; Dietary Proteins; Dietary Supplements; Energy Metabolism; Humans; Nutrients; Physical Education and Training; Sports
PubMed: 31713177
DOI: 10.1007/s13668-019-00293-1 -
Obesity (Silver Spring, Md.) Aug 2023Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein sources, especially red meat, impact weight loss-induced T2D management is unknown. This trial compared an HP diet including beef and a normal-protein (NP) diet without red meat for weight loss, body composition changes, and glucose control in individuals with T2D.
METHODS
A total of 106 adults (80 female) with T2D consumed an HP (40% protein) diet with ≥4 weekly servings of lean beef or an NP (21% protein) diet excluding red meat during a 52-week weight loss intervention. Body weight, body composition, and cardiometabolic parameters were measured before and after intervention.
RESULTS
Weight loss was not different between the HP (-10.2 ± 1.6 kg) and NP (-12.7 ± 4.8 kg, p = 0.336) groups. Both groups reduced fat mass and increased fat-free mass percent. Hemoglobin A1c, glucose, insulin, insulin resistance, blood pressure, and triglycerides improved, with no differences between groups.
CONCLUSIONS
The lack of observed effects of dietary protein and red meat consumption on weight loss and improved cardiometabolic health suggests that achieved weight loss, rather than diet composition, should be the principal target of dietary interventions for T2D management.
Topics: Animals; Cattle; Adult; Humans; Female; Obesity; Blood Glucose; Diabetes Mellitus, Type 2; Diet; Weight Loss; Body Composition; Cardiovascular Diseases; Dietary Proteins
PubMed: 37475689
DOI: 10.1002/oby.23815 -
Clinical Nutrition (Edinburgh, Scotland) Aug 2022Numerous studies have evaluated the effects of dietary protein on specific health outcomes. The aim of our umbrella review was to summarize the existing evidence between... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & AIMS
Numerous studies have evaluated the effects of dietary protein on specific health outcomes. The aim of our umbrella review was to summarize the existing evidence between the intake of dietary proteins and multiple health outcomes, and assess their strength and validity.
METHODS
Our study was registered at PROSPERO (No. CRD42021255938). We systematically searched PubMed, Embase, and Web of Science databases from inception to May 18, 2021, to identify relevant systematic reviews and meta-analyses of observational studies. The validated "A Measurement Tool to Assess Systematic Reviews" for assessing the methodological quality of included systematic reviews was utilized. For each association, we estimated the summary effect size using fixed and random effects methods, and the 95% confidence and prediction intervals. We also evaluated heterogeneity, evidence of small-study effects, and excess significance bias.
RESULTS
Overall, 16 articles with 58 meta-analyses were included. All studies were categorized as over moderate quality. On employing the random-effects model, fourteen (24.1%) meta-analyses were found to be significant at P < 0.05, whereas only one (1.7%) remained significant at P < 10. Twenty-two (37.9%) meta-analyses had large or very large heterogeneity. Evidence of small-study effects and excess significance bias was found for three (5.2%) meta-analyses, respectively. One meta-analysis was supported by highly suggestive evidence, indicating that a 5% increase in energy intake from animal protein was associated with 12% higher risk of type 2 diabetes (95% confidence interval [CI]: 1.08-1.17). Of note, the intake of animal and plant proteins had different health effects on type 2 diabetes, all-cause mortality, and risk of cardiovascular disease mortality.
CONCLUSIONS
Although the intake of dietary protein was associated with certain health outcomes, the strength of evidence was limited for most outcomes. Moreover, the source of dietary protein is an important factor that requires better consideration in future studies.
Topics: Bias; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dietary Proteins; Humans; Systematic Reviews as Topic
PubMed: 35810569
DOI: 10.1016/j.clnu.2022.06.005 -
Renal Failure Dec 2023Decreased dietary protein intake (DPI) may lead to protein-energy malnutrition and may be associated with increased mortality risk. We hypothesized that longitudinal...
BACKGROUND
Decreased dietary protein intake (DPI) may lead to protein-energy malnutrition and may be associated with increased mortality risk. We hypothesized that longitudinal changes in dietary protein intake have independent associations with survival in peritoneal dialysis (PD) patients.
METHODS
668 stable PD patients were selected in the study from January 2006 to January 2018 and were followed up until December 2019. Their three-day dietary records were collected at the baseline (the sixth month after PD) and thereafter every 3 months for two and a half years. The latent class mixed models (LCMM) were used to identify subgroups of PD patients with similar longitudinal trajectories of DPI. The relation between DPI (baseline and longitudinal data) and survival was examined using Cox model to estimate death hazard ratios. Meanwhile, different formulae were used to assess nitrogen balance.
RESULTS
The results showed that baseline DPI ≤ 0.60g/kg/day was associated with the worst outcome in PD patients. Patients with DPI 0.80-0.99g/kg/day and DPI ≥ 1.0g/kg/day both presented positive nitrogen balance; patients with DPI 0.61-0.79g/kg/day presented obviously negative nitrogen balance. Longitudinal association between time-dependent DPI and survival was found in PD patients. The consistently low DPI' (0.61-0.79g/kg/d) group was correlated with increased death risk as compared with the 'consistently median DPI' group (0.80-0.99g/kg/d, HR = 1.59, = 0.008), whereas there was no difference in survival between 'consistently median DPI' group and 'high-level DPI' group (≥1.0 g/kg/d, > 0.05).
CONCLUSION
Our study revealed that DPI ≥ 0.8 g/kg/day was beneficial to the long-term outcome for the PD population.
Topics: Humans; Dietary Proteins; Nitrogen; Peritoneal Dialysis
PubMed: 36861472
DOI: 10.1080/0886022X.2023.2182605 -
Current Opinion in Clinical Nutrition... Jan 2021In this review, the latest evidence on the influence of dietary protein and plasma amino acids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is... (Review)
Review
PURPOSE OF REVIEW
In this review, the latest evidence on the influence of dietary protein and plasma amino acids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is discussed.
RECENT FINDINGS
Increasing protein consumption during weight loss and maintenance may help reduce liver fat content. Conversely, high protein intake characteristic of the unhealthy Western diet is associated with increased NAFLD prevalence and severity. Plasma concentration of several amino acids, including branched-chain (BCAA) and aromatic amino acids (AAA), is altered in NAFLD. Excess amino acid availability contributes to intrahepatic fat accumulation and may reflect poor dietary habits and dysregulation of amino acid metabolic processing in both liver and peripheral tissues. Specific amino acid patterns, characterized by increased BCAA, AAA, alanine, glutamate, lysine levels, and decreased glycine and serine levels, may be used for early detection of NAFLD and noninvasive assessment of its histological severity.
SUMMARY
Mechanistic studies in NAFLD have been mostly focused on carbohydrate and fat metabolism, while little is known about the influence of protein and amino acids. Moreover, intervention and observational studies on the relation between protein intake and NAFLD yielded conflicting results. Filling the current knowledge gaps would help define the optimal diet composition for NAFLD prevention and management. Furthermore, metabolomics studies may provide insight into the pathogenesis of NAFLD, identify useful diagnostic and prognostic biomarkers, and unravel novel pharmacological targets and treatment options.
Topics: Amino Acids; Dietary Proteins; Humans; Lipid Metabolism; Liver; Non-alcoholic Fatty Liver Disease
PubMed: 33060460
DOI: 10.1097/MCO.0000000000000706 -
Journal of Renal Nutrition : the... Sep 2020To determine the sources of protein and phosphorus levels from the food consumed by patients on dialysis.
OBJECTIVE
To determine the sources of protein and phosphorus levels from the food consumed by patients on dialysis.
DESIGN AND METHODS
This is a retrospective, secondary data analysis of the Comprehensive Dialysis Survey study participants who had a baseline food frequency questionnaire and baseline lab data (N = 358). We examined intake of protein, phosphorus, and 7 other key nutrients from a subcohort of the Comprehensive Dialysis Survey based on the published National Kidney Foundation Kidney Dialysis Outcome Quality Initiative's nutrition recommendations. We studied the relationship of dietary protein source (plant or animal) with phosphorus intake using self-reported data from food frequency questionnaires. Variables included in final analysis are demographic, lab variables (albumin and prealbumin, alpha-1 acid glycoprotein, and C-reactive protein), and nutrition variables (calorie density, protein density, total fat, saturated fat, cholesterol, carbohydrates, phosphorus, calcium, sodium, potassium, plant-based protein, animal-based protein, and daily protein intake).
RESULTS
Most of the patients had a lower than recommended consumption of calories, protein, phosphorus, and potassium while sodium, total, and saturated fats were overconsumed. Patients intake of dietary protein and calories was proportional to the amount of food consumed for both plant- and animal-based food. The levels of dietary protein and phosphorus were significantly (P < .05) lower in patients who primarily consumed a plant-based diet than in those who mainly consumed an animal-based diet.
CONCLUSIONS
Consuming more plant-based protein as part of a varied diet could be nutritionally adequate while limiting intake of absorbable dietary phosphorus. More research in plant-based protein diets and their impact on patients with end-stage renal disease is needed.
Topics: Diet; Dietary Proteins; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Phosphorus; Renal Dialysis; Retrospective Studies; Surveys and Questionnaires
PubMed: 32276766
DOI: 10.1053/j.jrn.2019.11.006 -
Nutrients Nov 2021Feeding behavior is guided by multiple competing physiological needs, as animals must sense their internal nutritional state and then identify and consume foods that... (Review)
Review
Feeding behavior is guided by multiple competing physiological needs, as animals must sense their internal nutritional state and then identify and consume foods that meet nutritional needs. Dietary protein intake is necessary to provide essential amino acids and represents a specific, distinct nutritional need. Consistent with this importance, there is a relatively strong body of literature indicating that protein intake is defended, such that animals sense the restriction of protein and adaptively alter feeding behavior to increase protein intake. Here, we argue that this matching of food consumption with physiological need requires at least two concurrent mechanisms: the first being the detection of internal nutritional need (a protein need state) and the second being the discrimination between foods with differing nutritional compositions. In this review, we outline various mechanisms that could mediate the sensing of need state and the discrimination between protein-rich and protein-poor foods. Finally, we briefly describe how the interaction of these mechanisms might allow an animal to self-select between a complex array of foods to meet nutritional needs and adaptively respond to changes in either the external environment or internal physiological state.
Topics: Adaptation, Psychological; Animal Nutritional Physiological Phenomena; Animals; Appetite; Dietary Proteins; Eating; Feeding Behavior; Food Preferences; Homeostasis; Nutritional Status
PubMed: 34836357
DOI: 10.3390/nu13114103