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Nutrients Nov 2019While animal products are rich in protein, the adequacy of dietary protein intake from vegetarian/vegan diets has long been controversial. In this review, we examine the... (Review)
Review
While animal products are rich in protein, the adequacy of dietary protein intake from vegetarian/vegan diets has long been controversial. In this review, we examine the protein and amino acid intakes from vegetarian diets followed by adults in western countries and gather information in terms of adequacy for protein and amino acids requirements, using indirect and direct data to estimate nutritional status. We point out that protein-rich foods, such as traditional legumes, nuts and seeds, are sufficient to achieve full protein adequacy in adults consuming vegetarian/vegan diets, while the question of any amino acid deficiency has been substantially overstated. Our review addresses the adequacy in changes to protein patterns in people newly transitioning to vegetarian diets. We also specifically address this in older adults, where the issues linked to the protein adequacy of vegetarian diets are more complex. This contrasts with the situation in children where there are no specific concerns regarding protein adequacy because of their very high energy requirements compared to those of protein. Given the growing shifts in recommendations from nutrition health professionals for people to transition to more plant-based, whole-food diets, additional scientific evidence-based communications confirming the protein adequacy of vegetarian and vegan diets is warranted.
Topics: Diet, Vegetarian; Dietary Proteins; Humans; Nutritional Requirements
PubMed: 31690027
DOI: 10.3390/nu11112661 -
The American Journal of Clinical... Jun 2017: Considerable attention has recently focused on dietary protein's role in the mature skeleton, prompted partly by an interest in nonpharmacologic approaches to maintain... (Meta-Analysis)
Meta-Analysis Review
: Considerable attention has recently focused on dietary protein's role in the mature skeleton, prompted partly by an interest in nonpharmacologic approaches to maintain skeletal health in adult life. The aim was to conduct a systematic review and meta-analysis evaluating the effects of dietary protein intake alone and with calcium with or without vitamin D (Ca±D) on bone health measures in adults. Searches across 5 databases were conducted through October 2016 including randomized controlled trials (RCTs) and prospective cohort studies examining ) the effects of "high versus low" protein intake or ) dietary protein's synergistic effect with Ca±D intake on bone health outcomes. Two investigators independently conducted abstract and full-text screenings, data extractions, and risk of bias (ROB) assessments. Strength of evidence was rated by group consensus. Random-effects meta-analyses for outcomes with ≥4 RCTs were performed. Sixteen RCTs and 20 prospective cohort studies were included in the systematic review. Overall ROB was medium. Moderate evidence suggested that higher protein intake may have a protective effect on lumbar spine (LS) bone mineral density (BMD) compared with lower protein intake (net percentage change: 0.52%; 95% CI: 0.06%, 0.97%, : 0%; = 5) but no effect on total hip (TH), femoral neck (FN), or total body BMD or bone biomarkers. Limited evidence did not support an effect of protein with Ca±D on LS BMD, TH BMD, or forearm fractures; there was insufficient evidence for FN BMD and overall fractures. Current evidence shows no adverse effects of higher protein intakes. Although there were positive trends on BMD at most bone sites, only the LS showed moderate evidence to support benefits of higher protein intake. Studies were heterogeneous, and confounding could not be excluded. High-quality, long-term studies are needed to clarify dietary protein's role in bone health. This trial was registered at www.crd.york.ac.uk as CRD42015017751.
Topics: Bone Density; Bone Density Conservation Agents; Calcium; Calcium, Dietary; Dietary Proteins; Female; Fractures, Bone; Humans; Lumbar Vertebrae; Male; Osteoporosis; Vitamin D
PubMed: 28404575
DOI: 10.3945/ajcn.116.145110 -
Journal of the American Medical... Aug 2013New evidence shows that older adults need more dietary protein than do younger adults to support good health, promote recovery from illness, and maintain functionality.... (Review)
Review
New evidence shows that older adults need more dietary protein than do younger adults to support good health, promote recovery from illness, and maintain functionality. Older people need to make up for age-related changes in protein metabolism, such as high splanchnic extraction and declining anabolic responses to ingested protein. They also need more protein to offset inflammatory and catabolic conditions associated with chronic and acute diseases that occur commonly with aging. With the goal of developing updated, evidence-based recommendations for optimal protein intake by older people, the European Union Geriatric Medicine Society (EUGMS), in cooperation with other scientific organizations, appointed an international study group to review dietary protein needs with aging (PROT-AGE Study Group). To help older people (>65 years) maintain and regain lean body mass and function, the PROT-AGE study group recommends average daily intake at least in the range of 1.0 to 1.2 g protein per kilogram of body weight per day. Both endurance- and resistance-type exercises are recommended at individualized levels that are safe and tolerated, and higher protein intake (ie, ≥ 1.2 g/kg body weight/d) is advised for those who are exercising and otherwise active. Most older adults who have acute or chronic diseases need even more dietary protein (ie, 1.2-1.5 g/kg body weight/d). Older people with severe kidney disease (ie, estimated GFR <30 mL/min/1.73 m(2)), but who are not on dialysis, are an exception to this rule; these individuals may need to limit protein intake. Protein quality, timing of ingestion, and intake of other nutritional supplements may be relevant, but evidence is not yet sufficient to support specific recommendations. Older people are vulnerable to losses in physical function capacity, and such losses predict loss of independence, falls, and even mortality. Thus, future studies aimed at pinpointing optimal protein intake in specific populations of older people need to include measures of physical function.
Topics: Activities of Daily Living; Acute Disease; Aged; Aged, 80 and over; Chronic Disease; Dietary Proteins; Exercise; Geriatric Assessment; Geriatrics; Humans; Nutritional Requirements; Practice Guidelines as Topic; Sarcopenia
PubMed: 23867520
DOI: 10.1016/j.jamda.2013.05.021 -
Current Opinion in Clinical Nutrition... Jan 2009To draw attention to recent work on the role of protein and the amount of protein needed with each meal to preserve skeletal muscle mass in ageing. (Review)
Review
PURPOSE OF REVIEW
To draw attention to recent work on the role of protein and the amount of protein needed with each meal to preserve skeletal muscle mass in ageing.
RECENT FINDINGS
Ageing does not inevitably reduce the anabolic response to a high-quality protein meal. Ingestion of approximately 25-30 g of protein per meal maximally stimulates muscle protein synthesis in both young and older individuals. However, muscle protein synthesis is blunted in elderly when protein and carbohydrate are coingested or when the quantity of protein is less than approximately 20 g per meal. Supplementing regular mixed-nutrient meals with leucine may also enhance the muscle protein synthetic response in elders.
SUMMARY
On the basis of recent work, we propose a novel and specific dietary approach to prevent or slow down muscle loss with ageing. Rather than recommending a large, global increase in the recommended dietary allowance (RDA) for protein for all elderly individuals, clinicians should stress the importance of ingesting a sufficient amount of protein with each meal. To maximize muscle protein synthesis while being cognizant of total energy intake, we propose a dietary plan that includes 25-30 g of high quality protein per meal.
Topics: Aged; Aging; Dietary Proteins; Dietary Supplements; Exercise; Humans; Leucine; Muscle Proteins; Muscular Atrophy; Nutrition Policy; Protein Deficiency
PubMed: 19057193
DOI: 10.1097/MCO.0b013e32831cef8b -
Blood Purification 2021Over the last 2 decades, there has been a great accumulation of new evidence regarding the management of nutritional and metabolic aspects of kidney disease. The 2020... (Review)
Review
Over the last 2 decades, there has been a great accumulation of new evidence regarding the management of nutritional and metabolic aspects of kidney disease. The 2020 update to the KDOQI Clinical Practice Guideline for Nutrition in CKD provides a comprehensive up-to-date information on the understanding and care of patients with CKD. It provides updated information on nutritional aspects of kidney disease for the practicing clinician and allied health-care workers. The current manuscript provides an overview of the updated guideline statements on major subjects including nutritional assessment, dietary protein and energy intake, nutritional supplementation, micronutrients, and electrolytes. The guidelines are focused on dietary management rather than all possible nutritional interventions.
Topics: Dietary Proteins; Dietary Supplements; Energy Intake; Humans; Micronutrients; Nutrition Assessment; Nutritional Status; Renal Insufficiency, Chronic
PubMed: 33652433
DOI: 10.1159/000513698 -
Current Opinion in Clinical Nutrition... May 2015We provide an update on the recent advances in nutrition research regarding the role of protein intake in the development and treatment of sarcopenia of aging. (Review)
Review
PURPOSE OF REVIEW
We provide an update on the recent advances in nutrition research regarding the role of protein intake in the development and treatment of sarcopenia of aging.
RECENT FINDINGS
Specific muscle mass, strength and function cut-points for the diagnosis of sarcopenia have been identified. There is mounting evidence, as highlighted by multiple consensus statements, that the Recommended Dietary Allowance (0.8 g/kg body weight) may be inadequate to promote optimal health in older adults. Recent research indicates that in addition to total daily protein intake the timing of protein intake is also important to best stimulate muscle protein synthesis, and maintain muscle mass and function in older adults.
SUMMARY
Recent evidence suggests that the Recommended Dietary Allowance for protein is inadequate, and that the timing and distribution of protein consumption throughout daily meals may be as important as the total quantity. Research has continued to advance our understanding of protein's effects on muscle metabolism; however, there remains a need for large, long-term, randomized clinical trials examining whether the positive effects of dietary protein on muscle metabolism seen in acute studies will translate over the long term into gains of muscle mass, function, and the overall health of older adults.
Topics: Aged; Aging; Body Composition; Diet; Dietary Proteins; Humans; Muscle Proteins; Muscle, Skeletal; Nutritional Requirements; Sarcopenia
PubMed: 25807346
DOI: 10.1097/MCO.0000000000000162 -
The American Journal of Clinical... Mar 2016A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with... (Comparative Study)
Comparative Study Randomized Controlled Trial
BACKGROUND
A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise.
OBJECTIVE
The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition.
DESIGN
We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention.
RESULTS
As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = -0.34, P = 0.03).
CONCLUSIONS
Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg(-1) · d(-1) was more effective than consumption of a diet containing 1.2 g protein · kg(-1) · d(-1) in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.
Topics: Adipose Tissue; Adult; Body Composition; Body Fluid Compartments; Caloric Restriction; Diet; Dietary Proteins; Energy Intake; Exercise; Humans; Hydrocortisone; Male; Nutritional Requirements; Physical Exertion; Prospective Studies; Resistance Training; Single-Blind Method; Young Adult
PubMed: 26817506
DOI: 10.3945/ajcn.115.119339 -
Nutrients May 2019Adequate consumption of dietary protein is critical for the maintenance of optimal health during normal growth and aging. The current Recommended Dietary Allowance (RDA)...
Adequate consumption of dietary protein is critical for the maintenance of optimal health during normal growth and aging. The current Recommended Dietary Allowance (RDA) for protein is defined as the minimum amount required to prevent lean body mass loss, but is often misrepresented and misinterpreted as a recommended optimal intake. Over the past two decades, the potential muscle-related benefits achieved by consuming higher-protein diets have become increasingly clear. Despite greater awareness of how higher-protein diets might be advantageous for muscle mass, actual dietary patterns, particularly as they pertain to protein, have remained relatively unchanged in American adults. This lack of change may, in part, result from confusion over the purported detrimental effects of higher-protein diets. This manuscript will highlight common perceptions and benefits of dietary protein on muscle mass, address misperceptions related to higher-protein diets, and comment on the translation of academic advances to real-life application and health benefit. Given the vast research evidence supporting the positive effects of dietary protein intake on optimal health, we encourage critical evaluation of current protein intake recommendations and responsible representation and application of the RDA as a minimum protein requirement rather than one determined to optimally meet the needs of the population.
Topics: Diet, Reducing; Dietary Proteins; Energy Intake; Exercise; Health Knowledge, Attitudes, Practice; Humans; Muscle, Skeletal; Nutritional Sciences; Recommended Dietary Allowances; Wasting Syndrome
PubMed: 31121843
DOI: 10.3390/nu11051136 -
Nutrients Apr 2019Sports nutrition products are developed and targeted mainly for athletes to improve their nutrient intake, performance, and muscle growth. The fastest growing consumer... (Review)
Review
Sports nutrition products are developed and targeted mainly for athletes to improve their nutrient intake, performance, and muscle growth. The fastest growing consumer groups for these products are recreational sportspeople and lifestyle users. Although athletes may have elevated physiological protein requirements and they may benefit from dietary supplements, the evidence regarding the role of dietary protein and supplements in the nutrition of recreational sportspeople and sedentary populations is somewhat complex and contradictory. In high-protein diets, more undigested protein-derived constituents end up in the large intestine compared to moderate or low-protein diets, and hence, more bacterial amino acid metabolism takes place in the colon, having both positive and negative systemic and metabolic effects on the host. The aim of the present review is to summarize the impact of the high-protein products and diets on nutrition and health, in sportspeople and in sedentary consumers. We are opening the debate about the current protein intake recommendations, with an emphasis on evidence-based effects on intestinal microbiota and personalized guidelines regarding protein and amino acid supplementation in sportspeople and lifestyle consumers.
Topics: Amino Acids; Bacteria; Dietary Proteins; Dietary Supplements; Digestion; Exercise; Gastrointestinal Microbiome; Humans; Intestine, Large; Nutritional Status; Recommended Dietary Allowances; Sedentary Behavior; Sports; Sports Nutritional Physiological Phenomena
PubMed: 31013719
DOI: 10.3390/nu11040829 -
International Journal of Sport... Apr 2006Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets... (Review)
Review
Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets high in protein by some health professionals, media and popular diet books is given despite a lack of scientific data on the safety of increasing protein consumption. The key issues are the rate at which the gastrointestinal tract can absorb amino acids from dietary proteins (1.3 to 10 g/h) and the liver's capacity to deaminate proteins and produce urea for excretion of excess nitrogen. The accepted level of protein requirement of 0.8g x kg(-1) x d(-1) is based on structural requirements and ignores the use of protein for energy metabolism. High protein diets on the other hand advocate excessive levels of protein intake on the order of 200 to 400 g/d, which can equate to levels of approximately 5 g x kg(-1) x d(-1), which may exceed the liver's capacity to convert excess nitrogen to urea. Dangers of excessive protein, defined as when protein constitutes > 35% of total energy intake, include hyperaminoacidemia, hyperammonemia, hyperinsulinemia nausea, diarrhea, and even death (the "rabbit starvation syndrome"). The three different measures of defining protein intake, which should be viewed together are: absolute intake (g/d), intake related to body weight (g x kg(-1) x d(-1)) and intake as a fraction of total energy (percent energy). A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g x kg(-1) x d(-1), corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet. This is well below the theoretical maximum safe intake range for an 80 kg person (285 to 365 g/d).
Topics: Amino Acids; Body Weight; Dietary Proteins; Energy Metabolism; Exercise; Humans; Muscle, Skeletal; Nutritional Requirements; Safety
PubMed: 16779921
DOI: 10.1123/ijsnem.16.2.129