A newly published peer-reviewed paper in Critical Reviews in Food Science and Nutrition synthesizes findings from a February 2025 scientific workshop. 1 * The paper, authored by more than 20 international protein researchers, critically examines 11 widely held propositions about dietary protein needs and benefits and concludes that in some instances, the science is simply insufficient or not robust enough to interpret as support for select propositions.
What is this paper about?
The paper, titled " Examining Widely Held Propositions on Human Dietary Protein Needs and Benefits ," 1 is the proceedings of a workshop designed to explore current beliefs about dietary protein. Expert authors reviewed evidence on protein quantity, protein quality, essential amino acid (EAA) adequacy, digestibility, satiety, aging, muscle mass, weight loss, chrononutrition, and protein leverage, rating the strength of evidence for each proposition on a formal scale.
“Protein science has advanced significantly, but despite thousands of published studies, in some instances there is still a lack of publicly available quality data,” said Mitch Kanter, PhD, Principal, Mitch Kanter Health & Nutrition Insights and Adjunct Associate Professor at the University of Minnesota, first author on the paper and a primary organizer of the workshop. “The significance of this workshop was rooted to bring together the leading protein science experts to clarify what we know, identify what we still need to learn and encourage a more evidence-based discussion about dietary protein and human health.”
What did the experts find?
For most of the 11 propositions examined, experts concluded that full acceptance was not yet warranted based on available data, though many were rated as plausible and supported by preliminary evidence. Key findings include:
Protein quality matters as much as quantity. Protein foods differ in amino acid composition, digestibility, and bioavailability. The digestible indispensable amino acid score (DIAAS) is the recommended method for evaluating protein quality, and animal-sourced proteins generally rate higher than plant-sourced proteins.
Individual essential amino acids have distinct biological roles. Leucine, methionine, threonine, and the branched-chain amino acids (BCAAs) each affect specific metabolic pathways. Current Recommended Dietary Allowances (RDAs) for individual EAAs may underestimate true physiological needs for functions beyond basic protein synthesis.
Higher protein intake during weight loss is supported, but with nuance. Evidence suggests that protein intakes above the RDA (0.8 g/kg/day) can help preserve lean muscle mass during caloric restriction with most benefit observed when protein intake is maintained at habitual levels (expressed in g/kg/day) rather than simply increased in absolute grams.
Protein leverage is well-supported. There is strong experimental and observational evidence that humans prioritize protein intake, and that diets low in protein relative to fat and carbohydrates drive increased total calorie consumption — a mechanism potentially contributing to obesity.
Older adults likely need more protein than current guidelines recommend. Evidence suggests intakes of 1.2–1.6 g/kg/day or more may be needed to preserve muscle mass and function with aging.
High protein intake does not appear harmful to healthy kidneys. A systematic review of RCTs found no adverse kidney effects at intakes up to 1.5 g/kg/day or 20% of energy.
Protein may support fullness, but the science is more nuanced than common messaging suggests. While protein is widely viewed as a satiating nutrient and some studies show higher-protein diets can modestly increase fullness, experts concluded that current evidence does not firmly establish protein as uniquely or consistently the most satiating macronutrient. They noted that appetite is difficult to measure, that feelings of hunger or fullness do not always predict food intake in real-world settings, and that protein’s effects may depend on the food source, eating occasion, diet pattern and individual context.
Protein timing and distribution across the day shows early promise. Distributing protein more evenly across meals, particularly increasing protein at breakfast, may support muscle mass.
A threshold above which protein is harmful has not been established. The paper found no demonstrated adverse effects of protein intake above the RDA for healthy adults across several disease categories, including cardiovascular disease, type 2 diabetes, and sarcopenia.
What other research on dietary protein does the paper call for?
True scientific progress comes when experts are willing to examine assumptions, evaluate evidence carefully and identify where better data are needed. This paper identifies several priorities for future protein science:
Larger, longer randomized controlled trials with hard clinical endpoints (not just surrogate markers like muscle protein synthesis rates)
Better measurement tools for appetite and satiety
More data on protein needs across diverse populations, including children, adolescents, and people using GLP-1 receptor agonists for weight loss
Refined estimates of digestible and utilizable amino acid supply from mixed diets
Clearer distinction in guidance between protein quantity and protein quality
Support for this investigation: National Pork Board
As a collaborator in the workshop and co-author on this paper, National Pork Board Senior Director of Human Nutrition elaborates on how pork fits into the protein quality conversation. “The National Pork Board was proud to help support this important scientific workshop and contribute to the resulting publication,” said Kristen Hicks-Roof, PhD, RDN, LDN. “For pork, this work matters because it helps elevate the conversation from ‘more protein’ to ‘better protein’ guidance that considers protein quality, nutrient density, dietary patterns and how people actually eat. Pork has an important place in that conversation as a high-quality protein food that can support healthy, practical and enjoyable eating patterns.”
Pork was used as a practical example in the workshop and proceedings paper of how protein foods can be evaluated not only by grams of protein, but also by amino acid adequacy, nutrient density, affordability, accessibility, cultural relevance and fit within healthy dietary patterns. Dr. Hicks-Roof adds that, “Pork fits into the protein quality conversation because it is a complete, high-quality protein food that provides all essential amino acids and contributes important nutrients, including thiamin, niacin, vitamin B6, vitamin B12, selenium, zinc, phosphorus and choline.” 2 In addition, lean pork can help Americans meet nutrient needs as part of balanced, evidence-based dietary patterns. 3
As discussions about dietary protein evolve, pork offers a relevant example of a protein food that delivers both protein quantity and protein quality within meals that are accessible, versatile and familiar to many consumers.
About the National Pork Board
The National Pork Board has responsibility for Pork Checkoff-funded research, promotion and consumer information projects and for communicating with pork producers and the public. The Pork Checkoff funds national and state programs in consumer education and marketing, retail and foodservice marketing, export market promotion, production improvement, science and technology, swine health, pork safety, and environmental management and sustainability. For the past half century, the U.S. pork industry has delivered on its commitment to sustainable production and has made significant strides in reducing the environmental impact of pig farming. Through a legislative national Pork Checkoff, pork producers invest $0.35 for each $100 value of hogs sold. Importers of pork products contribute a like amount, based on a formula. For information on Checkoff-funded programs, pork producers can call the Pork Checkoff Service Center at 800-456-7675 or visit pork.org .
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*Support for the Dietary Protein Needs and Benefits workshop was provided by the following organizations: National Pork Board, Ajinomoto, Mars, Inc, Danone North America, National Cattlemen’s Beef Assn., The General Mills Company-Bell Institute of Health & Nutrition, American Egg Board-Egg Nutrition Center, National Dairy Council, International Flavors & Fragrances (IFF), Weight Watchers, Soy Nutrition Institute Global, Alliance for Potato Research & Education, (APRE) Dairy Council of California, Academy for Health & Lifespan Research, American Federation for Aging Research (AFAR), Glanbia Performance Nutrition, California Dairy Research Foundation, Science Unbound Foundation, Equii Foods. Personnel from the following organizations provided non-financial support in the preparation of the Appendix section of the manuscript: Danone North America, International Flavors & Fragrances, Marine Biologics, National Cattlemen’s Beef Assn, National Pork Board.
Critical Reviews in Food Science and Nutrition
Commentary/editorial
People
Examining widely held propositions on human dietary protein needs and benefits: a critical review of the science that shapes both the data and our understanding of an essential macronutrient
8-May-2026
Original Manuscript Authors Disclosure Statement MMK in the three years prior to the workshop received grant funding, consulting fees, and speaking honoraria from the Alliance for Potato Research and Education (APRE), The Global Dairy Platform, Indiana University Foundation, California Raisin Board, The Rite Stuff, Sabra Dipping Company, Marine Biologics, Dairy Council of California, California Dairy Research Foundation AWB in the three years prior to the workshop received travel expenses from the Alliance for Potato Research and Education (APRE), Institute for the Advancement of Food and Nutrition Sciences, International Food Information Council (IFIC), International Food Information Council Foundation (IFICF), National Academies of Science, Engineering, and Medicine, Soy Nutrition Institute Global, and Toronto 3D Knowledge Synthesis and Clinical Trials Foundation; speaking honoraria from APRE, American Society of Nutrition (ASN), Calorie Control Council, Eastern North American Region of the International Biometric Society, Eat Well Global, IFICF, National Restaurant Association, Potatoes USA, and Purchaser Business Group on Health; Editorial Board payments from ASN Statistical Review Board, and Spinger Publishing Company (International Journal of Obesity); consulting payments from IFICF, National Cattlemen’s Beef Assn, National Pork Board, NIH and NSF. He is involved in research for which his institution or colleagues received grants or contracts from APRE, Childhood Arthritis and Rheumatology Research Alliance, Haas Avocado Board, and NIH. He served as an unpaid Board of Trustee member of the IFIC assembly. NAB in the three years prior to the workshop received research grants, consulting fees, or speaking honoraria from Dairy Management Inc. (DMI), the National Cattlemen’s Beef Assn, National Pork Board, and Alliance for Potato Research and Education (APRE). TAD in the three years prior to the workshop received speaker honoraria from Indiana University School of Public Health-Bloomington and the National Cattlemen’s Beef Association. TAD is editor-in-chief of Critical Reviews in Food Science and Nutrition and played no role in the Journal’s evaluation of the manuscript. HJL in the three years prior to the workshop received research grant support during the prior 36 months from General Mills, National Cattlemen’s Beef Association/Beef Checkoff, National Dairy Council, Novo Nordisk, and National Pork Board/Pork Checkoff; consulting fees and speaking honoraria during the prior 36 months from General Mills and the National Cattlemen’s Beef Association. KCM in the three years prior to the workshop received research grant support during the prior 36 months from Cargill, General Mills, Global Organization for EPA and DHA, Greenyn Biotechnology, Haas Avocado Board, Helaina, Inc., Indiana University Foundation, Matinas BioPharma, MDLifespan, Medifast, Inc., National Cattlemen’s Beef Association/Beef Checkoff, National Dairy Council, Naturmega, NewAmsterdam Pharma, Novo Nordisk, PepsiCo., Pharmavite, and Ro; and received consulting fees from and/or served on advisory boards of 89bio, Acasti Pharma, Beren Therapeutics, Bragg Live Food Products, Campbell’s Company, Eli Lilly and company, Esperion Therapeutics, Inc., Helaina, Inc., Lonza Group, Matinas BioPharma, MDLifespan, National Cattlemen’s Beef Association, National Dairy Council, NewAmsterdam Pharma, NorthSea Therapeutics, Novo Nordisk and Seed, Inc. LCJvL in the three years prior to the workshop received research grants, consulting fees, speaking honoraria, or a combination of these for research on the impact of exercise and nutrition on muscle metabolism. A full overview on research funding is provided at: https://www.maastrichtuniversity.ml.l.vanloon CMW in the three years prior to the workshop received research grants, consulting fees, and speaking honoraria for research on diet and bone health including from The Global Dairy Platform, National Dairy Council, Cargill, and the California Prune Board. CMW is Chair of the Science Board of the International Life Sciences Institute U.S & Canada. DBA in the three years prior to the workshop received research grants, consulting fees, and speaking honoraria from The Academy for Health and Lifespan Conference; Academy for Health and Lifespan Research; Ajinomoto; Alliance for Potato Research and Education; Alliance for Aging Research; American Federation for Aging Research; American Academy of Optometry; American Society for Metabolic and Bariatric Surgery (CT Chapter); ArnetFox Schiff LLP; Baylor University College of Medicine; California Dairy Research Foundation; Cold Springs Harbor Laboratory; Banbury Center; Dairy Council of California; Dairy Management, Inc; Danone; Duke University; Eli Lilly and Company; eLife Sciences; Equii; General Mills; Georgia Southern University; Gerson Lehman Group, Inc.; Glanbia; Gordon and Betty Moore Foundation; Greenwood Asher & Associates; Henry Stewart Talks; Hevolution Foundation; Indiana University; Institute for Advance of Food & Nutrition Research; Korn Ferry; Linus Technology; Mayo Clinic Graduate School of Biomedical Sciences; Mars, Inc; Michigan State University; National Academy of Medicine (NAM); NAS/NASEM; National Cattlemen’s Beef Association; National Institute of Justice (NIJ); National Institutes of Health (NIH); National Pork Board; Novo Nordisk Foundation; Oregon Health & Sciences University; Pfizer, Inc.; Radicle Science; Reub Stoller Daniel; Roman Health Ventures, LLC; The Royal Society; Sage Publishing; Science Unbound Foundation; Seven Corners; Sigma Xi; Solae; Soy Nutrition Institute Global; Takeda Global Research & Development Center, Inc; Taylor & Francis; Texas A&M AgriLife Research; The Endocrine Society; The Obesity Society; The University of Alabama at Birmingham; Thorkild IA Sørensen; Tufts University; Uniformed Services University of the Health Sciences; University of Alabama (Tuscaloosa) Center for Convergent Bioscience and Medicine; University of California Los Angeles; University of Maryland; University of Mississippi Medical Center; University of New Mexico; University of Oklahoma; University of Southern Mississippi; University of South Carolina; USDA; VitaSoft; Wake Forest University Baptist Medical Center; WW (formerly Weight Watchers); Zero Longevity Science