The numbers behind the advice

Ask three expert bodies how much protein to eat and you'll get three different answers. The official US allowance is 0.8 grams per kilogram of body weight a day. A geriatric medicine group says at least 1.0 to 1.2 for people over 65. A sports nutrition society says 1.4 to 2.0 for people who exercise. It looks like a quarrel, but mostly it isn't. These are different kinds of number built for different jobs, and once you can tell which kind you're looking at, most of the confusion goes. So here's what sits behind them: what an RDA is and why most people need less than it, where each protein figure comes from, and why the official range for carbohydrate, fat and protein is one the National Academies now want removed.

Five numbers with five jobs

In the United States and Canada the official numbers are called the Dietary Reference Intakes, or DRIs. "The DRI framework was conceptualized in 1994, and the first reports were issued from 1997–2004", according to a 2016 history by Murphy and colleagues, one of whom, Allison Yates, is a former director of the Institute of Medicine's Food and Nutrition Board, which produced them.¹ The Institute of Medicine, now the National Academy of Medicine, is part of the National Academies, whose 2024 report cites the old DRI reports as "IOM".² Murphy's history lists the policies the DRIs have influenced, from dietary guidance to "food labeling".¹ The definitions below are copied from its Table 1, which this course read in full.

Five of the DRIs matter here, and the differences between them carry the whole lesson.

• The EAR, Estimated Average Requirement: "The average daily nutrient intake level that is estimated to meet the requirements of one-half of the healthy individuals in a particular life stage and gender group."
• The RDA, Recommended Dietary Allowance: "The average daily dietary nutrient intake level that is sufficient to meet the nutrient requirements of nearly all (97.5%) healthy individuals in a particular life stage and gender group; set at 2 SD above the mean requirement (EAR)."
• The AI, Adequate Intake: based on the intakes of apparently healthy groups that "are assumed to be adequate", and "provided when an EAR and RDA cannot be determined."
• The UL, Tolerable Upper Intake Level: "The highest average daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population."
• The AMDR, Acceptable Macronutrient Distribution Range: "The range of intake of protein, fat, and carbohydrate that is associated with a reduced risk of chronic disease, yet can provide adequate amounts of essential nutrients."

Notice the EAR and the RDA are the only two tied to a measured requirement. The AI is used when nobody could measure one: in the National Academies' words, it "does not bear a consistent relationship to the EAR or the RDA because it is set without the estimate of the requirement."² The UL is about harm, not need. And the AMDR is a range of shares of energy, a different kind of object altogether, which gets its own section below.

The same table gives each number a use. The RDA is for an individual, to "Plan intake with a low probability of inadequacy", and for groups the entry reads "Not used for groups." The EAR is the one used to "Assess the prevalence of inadequacy" in a group.¹ Hold on to that division of labour; the next section shows what goes wrong when the two are swapped.

A sixth, newer kind belongs to lesson 7. In 2019 a National Academies committee created a "Chronic Disease Risk Reduction (CDRR) value" and applied it to sodium.²

How a requirement becomes an allowance

People differ in how much of a nutrient they need. Measure the requirement in a few hundred healthy adults and you get a spread, the kind lesson 4 summed up with a standard deviation, the usual distance of a person from the group's average. The EAR is the middle of that spread. The RDA is the EAR plus two standard deviations. About 95 percent of a bell-shaped spread sits within two standard deviations either side of the average, so 2.5 percent sit above the top, which is where the definition's 97.5 comes from (this course's gloss). That's why only about one person in forty needs the RDA or more.

The National Academies put the same thing in terms of risk. For one person eating the EAR, "the risk of inadequacy is 0.5 (50 percent)"; at the RDA it is "only 0.02 to 0.03 (2 to 3 percent)".²

The protein figures rest on a 2003 meta-analysis by Rand, Pellett and Young of nitrogen balance studies, experiments that feed people set amounts of protein and track the nitrogen that goes in and comes out (this course's gloss on the method's name; lesson 2 met urinary nitrogen as the marker of protein).³ It gathered 235 people from 19 studies, each tested at three or more protein intakes. The middle requirement came to 0.65 grams of good-quality protein per kilogram a day, and the intake that would cover all but the top 2.5 percent of people to 0.83. This course read the abstract, which adds: "Individual requirements were found to fit a log-normal distribution", a spread with a longer tail on the high side than a bell curve has.

A 2016 review by Courtney-Martin and colleagues, whose full text this course read, gives the figures as the Institute of Medicine set them for older adults (the same authors dispute them, as the protein section shows): "the protein intake recommendations for elderly men and women were set at 0.66 and 0.8 g/kg/day as the EAR and RDA, respectively."⁵

Now work the step yourself. The RDA is the EAR plus two standard deviations, and here the EAR is 0.66 and the RDA 0.8. The gap is 0.14, so one standard deviation is 0.07 g per kg. (This course's arithmetic, which treats the spread as a bell curve; Rand's was log-normal, so take it as a close approximation.)

This course's drawing, on the same bell-curve approximation: the Institute of Medicine's older-adult EAR of 0.66 g per kg a day with one standard deviation of 0.07, so about one person in six needs more than 0.73 and about one in forty more than the RDA of 0.80. Rand found the real spread log-normal, with a longer tail on the high side than this curve has.

The margin is also why the RDA misleads when it's used on a group. If a survey counted everyone eating below the RDA as short, it would count the many people whose own requirement is lower than their intake. That's this course's reasoning from the definitions, and it's why the DRI table gives group assessment to the EAR and marks the RDA "Not used for groups."¹ The UL works the other way round. "At intakes between the RDA and the Tolerable Upper Intake Level (UL), the risks of inadequacy and of excess are both close to zero. At intakes above the UL, the risk of adverse effects may increase."² It is a line past which harm becomes possible, not a target to approach.

Protein, from 0.8 upwards

The adult RDA is 0.8 g per kg. This course could not read the official DRI report, whose pages didn't yield text, so the figure comes through reviews that cite it. Phillips, in 2017, writes that "Current protein requirements set the RDA at 0.80 g/kg/day, and this is based on nitrogen balance".⁴ The number itself isn't in doubt.

Take a 70 kg adult. At 0.8 g per kg that's 56 grams of protein a day. At 1.2 it's 84 grams and at 1.6 it is 112. (This course's arithmetic: 70 times each figure.) For comparison, the UK's government dietary recommendations give 55.5 grams a day for men aged 19 to 64 and 45.0 for women, in a table the research file read.¹⁴ So the RDA and the British figure land in the same place, and the higher figures ask for half as much again or double.

As of September 2026, the 2025-2030 Dietary Guidelines for Americans set "Protein serving goals: 1.2–1.6 grams of protein per kilogram of body weight per day, adjusting as needed based on your individual caloric requirements", 50 to 100 percent above an RDA that hasn't been revised (this course's arithmetic: 1.2 and 1.6 against 0.8).¹¹ The guidelines' own evidence for that figure, and the dispute over it, are lesson 9's. The older case for more than 0.8 comes from two places this course read, plus the sports evidence below.

The first is a different way of measuring the requirement. Courtney-Martin and colleagues, who developed the method they use, write: "Using the indicator amino acid oxidation (IAAO) method, we estimated the protein requirement in young adults and in both elderly men and women to be 0.9 and 1.2 g/kg/day as the EAR and RDA, respectively." And: "The requirement estimates however are ~40% higher than the current protein recommendations on a body weight basis."⁵

The method reads protein need from breath. While protein is short, a labelled amino acid is burned rather than built into new protein, and the amount burned, measured in the breath, falls as intake rises until it levels off; the intake where it levels off is the EAR (this course's summary of the authors' account). The developers' complaint about the older method is that nitrogen balance "tends to overestimate nitrogen intake and underestimate nitrogen excretion", which would make the requirement look lower than it is. One thing to hold on to: in this method "the upper 95% CI determines the RDA", so the 1.2 is the top of a confidence interval around the EAR, not the EAR plus two standard deviations of how people differ. The 1.2 and the 0.8 aren't built the same way. And the older-adult estimates rest on small studies, twelve women and six men.⁵

The disagreement is about measurement, which is the kind of dispute lesson 2 taught you to take seriously, and it is between the method's developers and a DRI figure set from the older nitrogen balance method. The research file has no primary statement from the other side answering the IAAO estimates directly, so this lesson can't give one.

The second is a position on older people. The PROT-AGE Study Group, convened by the European Union Geriatric Medicine Society, wrote in 2013 that "older adults need more dietary protein than do younger adults to support good health, promote recovery from illness, and maintain functionality."⁶ For people over 65 it "recommends average daily intake at least in the range of 1.0 to 1.2 g protein per kilogram of body weight per day", with "≥ 1.2 g/kg body weight/d" for those who are active and "1.2-1.5 g/kg body weight/d" for most with acute or chronic illness, except severe kidney disease, which comes up below. Its reason, in its own words: "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." In plain terms, more of what an older person eats is used by the gut and liver before it reaches muscle, and muscle responds less to what arrives (this course's gloss). It also names its own limits: "Protein quality, timing of ingestion, and intake of other nutritional supplements may be relevant, but evidence is not yet sufficient to support specific recommendations." This course read the abstract. It is an expert position paper, not a systematic review with graded evidence, which is the research file's note and the weight to give it.

What "the benefit plateaus" means

The figure 1.6 turns up again and again, and most of the time it traces to one paper. In 2018 Morton and colleagues pooled 49 randomised trials with 1,863 participants, every one of them combining protein supplements with resistance training for at least six weeks.⁷ This course read the abstract, and the full text for the passages quoted from it below.

The full paper, which is free, puts a range on that 1.62. It came from the 42 trial arms, 723 people, that reported total protein intake. The two-part line "explained more variation than a linear regression" but is "presented as a segmental regression despite not being statistically significant (p=0.079;figure 5)", and its 95 percent confidence interval runs from 1.03 to 2.20. The authors read that interval generously: "it may be prudent to recommend ~2.2 g protein/kg/d for those seeking to maximise resistance training-induced gains in FFM."⁷

A plateau is where extra protein stopped adding lean mass, in people doing resistance training. It is a ceiling on one benefit, not a recommended amount, and it says nothing directly about someone who isn't training, because nobody in the trials was in that position.

Two more lines in the abstract narrow it further. "The impact of protein supplementation on gains in FFM was reduced with increasing age", and it "was more effective in resistance-trained individuals" (the abstract gives 0.75 kg for that difference, with a 95 percent confidence interval of 0.09 to 1.40). So the benefit was largest in experienced lifters and shrank with age. That sits well with PROT-AGE's "declining anabolic responses" (this course's reading), and Morton's authors draw PROT-AGE's moral from it, not the opposite one: they had "only 13 studies that met our inclusion criteria in older (>45 years) individuals", and they say future trials in older people "should focus on using higher protein doses".⁷

Ask both questions of it. Mental Fitness lesson 2's first: what did the comparison group get? The full paper says "the comparator group received an identical RET intervention but was non-supplemented or placebo-supplemented."⁷ Then this course's: the extra protein came instead of what? A supplement on top of an unchanged diet adds calories as well as protein, and unless the placebo matched its calories, a pooled figure can't say how much of the third of a kilogram belongs to each (this course's reasoning). The parts of the paper this course read don't say what the placebos were.

The International Society of Sports Nutrition, in a 2017 position stand, says that "an overall daily protein intake in the range of 1.4-2.0 g protein/kg body weight/day (g/kg/d) is sufficient for most exercising individuals".⁸ Its audience is in the name. This course read the abstract.

Protein and the kidneys

Higher protein raises one safety question the sources answer in two parts, and the two parts are about different people.

For people with healthy kidneys, Devries and colleagues pooled 28 trials with 1,358 participants in 2018, comparing higher-protein diets, meaning at least 1.5 g per kg, or 20 percent of energy, or 100 grams a day, with normal or lower ones.⁹ The change in kidney filtering, measured as the glomerular filtration rate, "did not differ between interventions": the standardised difference, Mental Fitness lesson 2's kind of effect size, was 0.11, with a 95 percent confidence interval from -0.05 to 0.27. Measured only at the end, filtering was slightly higher on the high-protein diets, an effect the authors call "trivial" and don't read as harm. Their conclusion: "HP intakes do not adversely influence kidney function on GFR in healthy adults." Two of its authors, Morton and Phillips, also wrote the Morton review above, which calls for "higher protein doses" in trials of older people, so this reassurance comes from researchers on the higher-protein side. That isn't a conflict of interest, and a nephrologist would still want to know it. They name "the unclear risk of selection bias of the included trials" as the main limitation, and the trials only had to last more than four days. This course read the abstract.

For people with chronic kidney disease the advice runs the other way. The kidney guideline group KDIGO, in its 2024 guideline, says: "We suggest maintaining a protein intake of 0.8 g/kg body weight/d in adults with CKD G3–G5", and "Avoid high protein intake (>1.3 g/kg body weight/d) in adults with CKD at risk of progression."¹⁰ G3 to G5 are the guideline's categories for a filtering rate below 60 in its units, which it treats as low; which category a person is in is for their doctor. This course read the guideline's summary of recommendations. PROT-AGE makes the same exception: older people with severe kidney disease not on dialysis "may need to limit protein intake."⁶

Put the numbers side by side and the tension is plain. KDIGO's "avoid" line of 1.3 sits inside PROT-AGE's range for older people with illness and below the whole of the sports society's range. And it falls inside the 2025-2030 US guidelines' goal of 1.2 to 1.6 (as of September 2026), the one figure here aimed at every adult; the research file notes that those guidelines tell people with a chronic disease to talk to their clinician.¹¹ A figure that is reasonable for a healthy lifter can be one a kidney specialist would tell a patient to avoid.

A range the National Academies want gone

The AMDR puts limits on each macronutrient as a share of energy. For adults it is 45 to 65 percent of energy from carbohydrate, 20 to 35 percent from fat and 10 to 35 percent from protein.²

The committee's conclusion is blunt: "The committee concludes that the approach used to derive the AMDRs is not consistent with current evidence-based standards." Its first recommendation is that "the federal DRI working group should remove the Acceptable Macronutrient Distribution Range from the panel of nutrient intake values considered in the DRI framework." It doesn't tell anyone to stop using the ranges tomorrow: "some users may wish to continue to apply the AMDR values. However, users should realize their limitations if they continue to employ these ranges." The research file read the report's Summary and chapters 3, 5 and 6 in full.²

The same report says why the question has moved: "for the most part, dietary guidance now emphasizes the quality of macronutrients rather than total quantity of macronutrients". It also has some history. The 1989 RDAs had recommended fat "at amounts not to exceed 30 percent of dietary energy", and the committee adds that this was "albeit in the absence of data to support the supposition".² So the 1989 panel set a numerical fat limit, on the committee's own account, without data to support it. Lesson 6 takes up what the evidence on fat now shows.

The report makes a structural point too. EARs and RDAs "were set for carbohydrate, based on glucose use by the brain, and for protein, based on meta-analyses of nitrogen balance studies", while "Based on a lack of evidence for a dietary requirement, no EARs or RDAs were set for fat, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or cholesterol."² So when you see an app treat 35 percent fat as if it were an upper limit, it is treating a range set by judgement as though it were a threshold set by measurement.

The kind of carbohydrate, not the amount

If quality matters more than quantity, what does quality mean, and how would you measure it? The best evidence the course read is a 2019 series of reviews in The Lancet by Reynolds and colleagues, funded in part by the World Health Organization.¹² It compared three markers of carbohydrate quality across "185 prospective studies and 58 clinical trials with 4635 adult participants", excluding people with chronic disease, weight-loss trials and supplement trials. This course read the abstract.

The markers were dietary fibre, whole grains, and glycaemic index and load, which in brief are measures of how much a carbohydrate food raises blood sugar (this course's gloss).

For fibre: "Observational data suggest a 15-30% decrease in all-cause and cardiovascular related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers". "Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g." "Similar findings for whole grain intake were observed." But for the glycaemic measures: "Smaller or no risk reductions were found with the observational data when comparing the effects of diets characterised by low rather than higher glycaemic index or load."

And the grades: the certainty of evidence was "moderate for dietary fibre, low to moderate for whole grains, and low to very low for dietary glycaemic index and glycaemic load."¹²

Where do the fibre figures on guidelines come from? The UK's recommendation for adults aged 19 to 64 is 30 grams a day, from a 2015 report by its Scientific Advisory Committee on Nutrition.¹⁴ The US figure is set by energy. This course didn't read the DRI fibre text itself, but the American Diabetes Association's 2026 standards, which use the DRI-based number, say "at least 14 g fiber per 1,000 kcal".¹³ At 2,000 calories a day that's 28 grams, inside Reynolds' 25 to 29 gram band (this course's arithmetic).

Most Americans fall short. The 2020-2025 US guidelines, which the research file read, say: "More than 90 percent of women and 97 percent of men do not meet recommended intakes for dietary fiber."¹⁵

One more thing connects this to lesson 3. The carbohydrate-insulin model, at its authors' own strongest, is not a claim about carbohydrate as a whole. Its target is a kind: "Rapidly digestible carbohydrates, acting through insulin and other hormones, cause increased fat deposition, and thereby drive a positive energy balance."¹⁶ That is a claim about weight, and Reynolds' glycaemic finding is about disease, so one doesn't test the other. But both sides of that dispute, and Reynolds, are arguing about which carbohydrate, not how much.

What people get wrong

"The RDA is the amount you need." It is set two standard deviations above the average need, so it covers about 97.5 percent of healthy people and is more than most of them require. Eating below it doesn't mean you're short. Between the EAR and the RDA, the chance of being short falls from one half towards 2 or 3 percent. That is on the DRI's own estimate of need; for protein, the IAAO researchers argue the estimate itself is too low, so the RDA isn't a ceiling on need either.

"More protein is always better." Morton's trials estimated that lean mass stopped rising at about 1.6 g per kg, with an interval from about 1.0 to 2.2, in people who were training, and the average extra gain from supplements was about a third of a kilogram. For people with chronic kidney disease, KDIGO advises against going above 1.3. What the evidence supports depends on who you are and what outcome you mean.

"The macronutrient ranges are scientific limits." The body that published the AMDR now says it was set by "subjective interpretation of the data" and should be removed. A diet outside 20 to 35 percent fat isn't shown by the AMDR to be harmful, and one inside it isn't shown to be safe.

"Carbs are the problem." "Carbohydrate" covers wholegrain oats and a fizzy drink. The fibre evidence separates them, the National Academies say guidance has moved to quality, and even the carbohydrate-insulin model names "Rapidly digestible carbohydrates" as its target. Whether a lower carbohydrate pattern suits some people is a separate question, and lesson 9 gives it in its proponents' words.

Practice

Connections

Back. Lesson 4 weighed diets that moved the macronutrients around; this lesson asks where the official figure for each came from. Lesson 4 also taught the standard deviation, which is the whole mechanism of the RDA. Before believing any claim that people eat too little of something, ask lesson 2's question about how the intake was measured. Lesson 1's question, instead of what, applies to Morton's supplement trials and to whole grains, and Mental Fitness lesson 2's, what the other group got, is answered by Morton's full paper: training plus nothing or a placebo.

Forward. Fat got an AMDR and no RDA, and a 30 percent limit set without data to support it. Lesson 6 asks what the evidence on fat and the heart shows now, and why the answer depends on what replaces the fat. Lesson 9 takes up the 2025-2030 US guidelines, released in January 2026, including their protein goal.

Go deeper

• Murphy and colleagues, 2016, free at PubMed Central. This course read the full text. A short history of how the DRIs were built by people who built them, and the clearest table of the definitions.
• Rethinking the AMDR, National Academies, 2024, free from the National Academies Press. The research file read the Summary and chapters 3, 5 and
  6. A committee explaining in plain terms why a number it once published should go.
• Morton and colleagues, 2018, free at PubMed Central. This course read the abstract and, in the full text, the Methods, the breakpoint result and the Discussion. The source of the 1.6 figure, and worth reading for how small and specific the effect is and how wide the interval around the 1.6.
• Reynolds and colleagues, 2019 in The Lancet. This course read the abstract. The evidence behind the fibre figures, with each marker graded separately.

Sources

1. S. P. Murphy, A. A. Yates, S. A. Atkinson, S. I. Barr and J. Dwyer, "History of Nutrition: The Long Road Leading to the Dietary Reference Intakes for the United States and Canada", Advances in Nutrition 7(1), 2016, pp. 157 to 168, doi 10.3945/an.115.010322. Read: the full text via PubMed Central, with Table 1 (definitions) extracted verbatim, and the abstract. Supports: the dates of the framework, "food labeling", the five definitions, and the uses column quoted; the abstract names the "Food and Nutrition Board of the Institute of Medicine". That Yates directed the Food and Nutrition Board is the research file's note.
2. National Academies of Sciences, Engineering, and Medicine, Rethinking the Acceptable Macronutrient Distribution Range for the 21st Century: A Letter Report, National Academies Press, 2024, PMID 39680697. Read: the Summary and chapters 3, 5 and 6 in full. Supports: the AI sentence, the risk figures and the UL sentence (notes to Figure 3-1, citing IOM 2006), the CDRR, the AMDR table (Table 3-1), the verdict, the recommendation and interim note, the quality sentence, the 1989 history and the basis of the carbohydrate and protein EARs. The report's Front Matter, fetched at this lesson's review, supports that the Institute of Medicine is now the National Academy of Medicine.
3. W. M. Rand, P. L. Pellett and V. R. Young, "Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults", American Journal of Clinical Nutrition 77(1), 2003, pp. 109 to 127, doi 10.1093/ajcn/77.1.109. Read: the abstract. Supports: the 235 subjects and 19 studies, the 0.65 and 0.83 figures, and the log-normal spread. The gloss on nitrogen balance is this course's.
4. S. M. Phillips, "Current Concepts and Unresolved Questions in Dietary Protein Requirements and Supplements in Adults", Frontiers in Nutrition 4, 2017, 13, doi 10.3389/fnut.2017.00013. Read: the full text via PubMed Central, for the quotations the research file records. Supports: the quotation on the 0.80 RDA and nitrogen balance. The official DRI report was not read; its pages did not yield text.
5. G. Courtney-Martin, R. O. Ball, P. B. Pencharz and R. Elango, "Protein Requirements during Aging", Nutrients 8(8), 2016, 492, doi 10.3390/nu8080492. Read: the full text via PubMed Central, and the abstract. Supports: the older-adult EAR and RDA as set, both IAAO quotations, the account of the method (summarised in the body, with its RDA quoted), the nitrogen balance quotation and the sample sizes. That the authors developed the IAAO method is the research file's note.
6. J. Bauer and colleagues, "Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group", Journal of the American Medical Directors Association 14(8), 2013, pp. 542 to 559, doi 10.1016/j.jamda.2013.05.021. Read: the abstract. Supports: every PROT-AGE quotation and figure, including its reason and the kidney exception. The plain-terms gloss of "splanchnic extraction" is this course's. That it is an expert position paper rather than a graded systematic review is the research file's note.
7. R. W. Morton and colleagues, "A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults", British Journal of Sports Medicine 52(6), 2018, pp. 376 to 384, doi 10.1136/bjsports-2017-097608. Read: the abstract, and the full text via Europe PMC for the Methods sentence on comparison groups, the breakpoint result and the Discussion; supplementary tables not opened. Supports: the 49 trials and 1,863 participants, the lean mass and strength figures, the breakpoint and its interval, the 42 arms and 723 participants, the p value, the 2.2 suggestion, the comparison groups, the 13 older-adult studies, the call for higher doses, the age and training moderators and the conclusion.
8. R. Jäger and colleagues, "International Society of Sports Nutrition Position Stand: protein and exercise", Journal of the International Society of Sports Nutrition 14, 2017, 20, doi 10.1186/s12970-017-0177-8. Read: the abstract. Supports: the 1.4 to 2.0 range.
9. M. C. Devries and colleagues, "Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis", Journal of Nutrition 148(11), 2018, pp. 1760 to 1775, doi 10.1093/jn/nxy197. Read: the abstract. Supports: the 28 trials, 1,358 participants, the definition of a high protein intake, the change and post-only results, the limitation, the trial length and the conclusion. The author overlap with Morton is from the two author lists the research file records.
10. KDIGO CKD Work Group, "KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease", Kidney International 105(4S), 2024, pp. S117 to S314, doi 10.1016/j.kint.2023.10.018. Read: the summary of recommendations. Supports: Recommendation 3.3.1.1 and Practice Point 3.3.1.1 as quoted (the grade code after the first is left off), and the meaning of G3 to G5 from Recommendation 3.15.1.1 and Table 11 of the same summary.
11. U.S. Department of Health and Human Services and U.S. Department of Agriculture, Dietary Guidelines for Americans, 2025-2030, January 2026, cdn.realfood.gov/DGA.pdf. Read: the whole document. Supports: the protein goal as quoted, dated September 2026. The 50 to 100 percent is this course's arithmetic. That the guidelines tell people with a chronic disease to talk to their clinician is the research file's summary, not a quotation. Lesson 9 carries the rest.
12. A. Reynolds, J. Mann, J. Cummings, N. Winter, E. Mete and L. Te Morenga, "Carbohydrate quality and human health: a series of systematic reviews and meta-analyses", The Lancet 393(10170), 2019, pp. 434 to 445, doi 10.1016/S0140-6736(18)31809-9. Read: the abstract. Supports: the design, the exclusion, every quotation, the certainty grades and the funders. That the hard outcomes are all observational is the research file's note.
13. American Diabetes Association Professional Practice Committee, Standards of Care in Diabetes, 2026, section 5, on facilitating positive health behaviours, Diabetes Care, 2026, doi 10.2337/dc26-S005. Read: the carbohydrate and eating-pattern sections of the full text via PubMed Central. Supports: the 14 g per 1,000 kcal figure. That it is the DRI-based figure is the research file's note; the DRI fibre text was not read.
14. Public Health England, Government Dietary Recommendations, August 2016, on the Eatwell Guide page at GOV.UK. Read: tables 1 and 2 and their footnotes. Supports: the protein figures for men and women aged 19 to 64, the 30 g fibre figure and its SACN 2015 source.
15. U.S. Department of Agriculture and U.S. Department of Health and Human Services, Dietary Guidelines for Americans, 2020-2025, 9th edition, December 2020, through an Internet Archive copy. Read: the Executive Summary and the adult fibre section. Supports: the fibre quotation.
16. D. S. Ludwig and colleagues, "The carbohydrate-insulin model: a physiological perspective on the obesity pandemic", American Journal of Clinical Nutrition 114(6), 2021, pp. 1873 to 1885, doi 10.1093/ajcn/nqab270. Read: the abstract and named sections of the full text, as lesson 3 records. Supports: the quotation on rapidly digestible carbohydrates.
17. NIH Office of Dietary Supplements, iron fact sheet for consumers, updated 17 August 2023, read through an Internet Archive snapshot of 18 September 2026. Read: the page, with its tables. Supports: the adult recommended amounts and upper limit in the exercise, and the vegetarian note, which is paraphrased.