The 2025–2030 edition of the Dietary Guidelines for Americans, published this month under the banner “Eat Real Food” at realfood.gov, is the most directive version of the federal guidance in years. Its first substantive instruction is about protein: “Prioritize Protein Foods at Every Meal.”
Tucked into that section is the number that has travelled through nutrition circles since the document appeared. The guidelines now set a “protein serving goal” of 1.2 to 1.6 grams of protein per kilogram of body weight per day, “adjusting as needed based on your individual caloric requirements.” For a 70-kilogram adult, that works out to roughly 84 to 112 grams a day. The consumer table published by the Academy of Nutrition and Dietetics, by contrast, still lists 46 grams a day for women and 56 grams for men aged 19 and older — figures derived from the long-standing Recommended Dietary Allowance.
The two are not in direct conflict, but they are not the same kind of number either, and the distance between them is the most interesting thing about the new guidance.
What the new guidance actually says
The short version, taken from the document’s own opening pages: build meals on “whole, nutrient-dense foods — protein, dairy, vegetables, fruits, healthy fats, and whole grains,” paired with “a dramatic reduction in highly processed foods.” That last phrase follows a category the largest recent synthesis tied to higher risk of several conditions.
On protein it asks for variety across animal sources — eggs, poultry, seafood, red meat — and plant sources: beans, peas, lentils, legumes, nuts, seeds and soy. Vegetables and fruits get their own serving goals, three and two a day, and they sit next to protein for a reason: most people fall short on them, as our piece on the signs you are not eating enough vegetables sets out. Dairy is set at three servings a day within a 2,000-calorie pattern, full-fat and without added sugars. A gut-health note adds that fermented foods such as sauerkraut, kimchi, kefir and miso, along with high-fibre foods, support a diverse microbiome, while highly processed foods “can disrupt this balance.”
It is worth being precise about what this document is. Dietary guidelines are a policy synthesis of existing evidence, revised every five years — not a new set of trial results. The protein figure is a target, and its practical force lands on the food supply, school meals and clinical counselling as much as on any individual plate.
Why the older number was lower
The 0.8 grams per kilogram that many people recognise as “the protein requirement” is the RDA set by the National Academy of Medicine. Harvard’s Nutrition Source describes it plainly as “a minimum” — enough to keep an average adult in balance, not a target for anything better. By that arithmetic, a 140-pound person needs about 50 grams a day and a 200-pound person about 70 grams.
MedlinePlus frames the same nutrient differently again, as 10% to 35% of total calories, and offers a kitchen measure that is more useful than gram-counting: an ounce of a protein-rich food — meat, fish, an egg, a quarter-cup of tofu, half a cup of cooked beans — carries roughly seven grams of protein.
The new target sits above all of these. Its lower edge, 1.2 g/kg, is near the intake long suggested for older adults, who tend to need more protein to build muscle. Its upper edge, 1.6 g/kg, is not arbitrary either: it is close to where the strongest trial evidence stops showing benefit.
Where the trial evidence stops
The most-cited study here is a 2018 systematic review and meta-analysis in the British Journal of Sports Medicine. Pooling 49 randomised trials and 1,863 participants, it found that protein supplementation during resistance training did increase strength and lean mass — by a mean of 2.49 kg on one-repetition-maximum strength and 0.30 kg of fat-free mass — and that gains in fat-free mass stopped accumulating once total intake passed about 1.6 grams per kilogram per day.
A 2026 Bayesian network meta-analysis in Frontiers in Nutrition points the same way from a different angle. Across 36 trials and 1,552 participants, whey protein ranked first for lean-mass gains, with a dose–response curve that flattened at roughly 30 to 35 grams a day of supplemental whey. In participants aged 65 and over, whey’s advantage narrowed and casein or mixed proteins looked comparatively better — though that subgroup rested on only nine trials, and the authors call their dose estimates exploratory. Plant proteins showed smaller effects, with low to very low certainty in the analysis.
The limits here matter as much as the results. These trials ran for weeks to months, measured muscle size and strength, and were conducted almost entirely in people doing supervised resistance training at least twice a week. That is a reasonable basis for what an active person should eat around training. It says very little about whether everyone else needs to push protein toward the top of the new range.
The source may matter more than the total
The longer-running question about protein is not “how much” but “from where,” and on that the new guidance is deliberately even-handed.
Harvard’s Nutrition Source reports that in a cohort of more than 130,000 men and women followed for up to 32 years, the share of calories coming from total protein was not related to overall mortality — but the source of that protein was.
A 2026 analysis of the Golestan cohort in Iran, published in BMC Public Health, followed 43,050 adults aged 40 to 75 for a mean of 15 years. Each additional 10 grams a day of total or animal protein was associated with about a 2% higher risk of all-cause and cardiovascular death; plant protein was associated with a 3% lower risk of all-cause death; and replacing total or animal protein with carbohydrate or fat was associated with lower total and cardiovascular mortality. That is observational data from food-frequency questionnaires in a single population — a signal worth noting, not a settled verdict.
What we did not find
Nothing in the evidence we reviewed shows that reaching 1.2 to 1.6 grams per kilogram extends life or prevents disease in the general population. The randomised evidence is about muscle, in trained people, over weeks. The outcome evidence is observational, and it is mixed — particularly for animal protein.
For older adults, a 2026 analysis of the Health and Retirement Study in Frontiers in Nutrition tracked frailty transitions in 6,982 people aged 50 to 102. A dietary score emphasising protein density and carbohydrate quality was associated with a lower intensity of moving from robust to pre-frail, and from pre-frail to death. The authors are candid that their score is unvalidated and that the findings “do not establish a causal effect of diet on frailty transitions.” It is a lead, not a rule.
What this does not say
The guidelines set a target, not a prescription for any one person, and they tie it explicitly to individual calorie needs. Protein supplements are not the point of them: the document’s emphasis is protein foods, and the dietitians’ own guidance notes that most Americans already get enough protein overall but “lack variety,” encouraging more seafood and legumes rather than more powder.
Anyone managing kidney disease, or any condition for which a clinician has advised a specific protein intake, should talk to a healthcare professional before changing what they eat. As with everything on this site, this is information about a claim, not medical advice.