The per-capita model

One person. One year. Every number sourced.

What it takes to feed one average American — in calories, kilograms, acres, gallons, kilowatt-hours, and kilograms of CO₂e — by the day, by the month, by the year, and by what's actually on the plate. Built from USDA ERS, NASS, USGS, EPA and EIA primary data, with every derivation documented in the corpus model files.

Show every figure
Read the numbers honestly. The model integrates data across a 16-year window (LAFA 2010–2023, land use 2017, irrigation 2022–23, water 2015, energy 2012, GHG 2023); each total is divided by its own year's population. Monthly figures are annual ÷ 12; daily figures are annual ÷ 365. Land does not divide: the same acres work all year, so the land card holds still while the flows scale. Full caveats in the verification report.

The one finding that moves everything

Beef is 5% of food mass — but 77% of the cropland footprint, 32% of the water footprint, and 40% of diet greenhouse gases. It is the only lever that moves the model by tens of percent.

Shifting the same 2,450 kcal/day toward the Dietary Guidelines pattern trims the land footprint from 1.92 to 1.86 acres; deeper protein shifts (EAT-Lancet-style, vegetarian) move land, water and GHG by 30–70%. No packaging, transport, or waste intervention approaches this range — food miles are real but small; the protein portfolio is structural. The tables below show exactly where each footprint sits.

THE PLATE, DRAWN

The same finding, as a picture. The plate on the left is one person's food — switch what it's weighed in, and watch the wedges move: a sliver of beef on the plate becomes most of the field. Hover or tap anything (wedges, bars, chips) for its numbers in the current time view; click to pin.

The same plate, weighed four ways

Each bar is 100% of that measure for one person. Cropland stays annual (a standing footprint). Added fats & oils have no matched land or water intensity in any source, so they are absent from those two bars — a flagged gap, not a zero. Every value here is also in the table below; shares are computed from those twelve rows exactly as shown (the "roughly" figures in the next section fold in source-level residual lines, so they can differ by a few points). Colors mark food family (warm = animal, green = plant, blue = mixed added fats), and the palette passes the colorblind-separation checks in both themes.

WHERE IT GOES — BY FOOD TYPE

One person's food, split into the groups the sources actually measure. Bars show each food's share of the column's largest value. Every animal row is marked — the plant rows are the vegetarian's footprint, near enough.

Food Mass Land (m²/yr) Water Greenhouse gases

Computed from the table: animal foods carry roughly 95% of the diet's cropland-and-pasture footprint, 68% of its water footprint, and 82% of its greenhouse gases, from about 38% of its mass. Land is a standing footprint and stays annual in every view.

Sources & boundaries. Masses: USDA ERS Loss-Adjusted Food Availability (composite of latest years, 2010–2023), meat aggregate split by ERS availability shares. Land: Poore & Nemecek (2018) global intensities × LAFA masses — converges within 1.5% of USDA ERS ERR-273's U.S. top-down figure. Water: Mekonnen & Hoekstra (2012) global green+blue+grey intensities — mostly rainfall ("green") water; U.S. blue-water accounting uses ERR-273. GHG: Heller & Keoleian (U-M CSS20-01) U.S. diet LCA; their small residual lines (lamb 12.2, soy 3.0, legumes 2.8, veal 0.4 kg CO₂e/yr) are omitted from the rows. Added fats & oils carry no matched land/water intensity in any source — shown as n.a. rather than guessed. Full derivations: corpus files 01–03, 05.

THE PLATE VS THE GUIDELINES

Where the calories come from — and how the actual plate compares with the Dietary Guidelines pattern. Americans under-eat fruit, dairy and vegetables, and over-eat protein foods, added fats and added sugars.

Food group Calories Share of calories vs DGA target

Calories: ERS LAFA, loss-adjusted, composite of each group's latest year. DGA comparison: Healthy U.S.-Style Pattern at 2,000 kcal (DGA 2020–2025, Table 1-1) against LAFA food-pattern equivalents — vegetables at 71% of target, fruit 41%, dairy 49%, grains 111%, protein foods 145%, oils 237%, added sugars 173% of the <10%-of-calories limit.

The macronutrient frame — carbohydrate, protein, fat

130 g
carbohydrate RDA per adult per day — the AMDR band is 45–65% of calories
DGA 2020–2025 App. 1 · NAM DRIs
46–56 g
protein RDA per adult per day (female–male); actual protein-food intake runs 145% of the DGA pattern
DGA App. 1 · ERS LAFA
44–78 g
fat implied by the 20–35% AMDR at 2,000 kcal per day; actual added fats & oils ran 63.9 g/day when last measured (2010)
DGA App. 1 · ERS LAFA
21.6 tsp
actual added sugars per day vs a <12 tsp (<10% of calories) limit — 173% of the line
ERS LAFA 2023 · DGA

The corpus carries measured intake by food group (LAFA) and macronutrient targets (DGA/DRI); a measured macronutrient split of the actual U.S. diet would come from NHANES, which is a flagged Phase 2 addition — LAFA and NHANES are known to diverge for several groups, so the two are not silently merged here.

CHANGE THE DIET, CHANGE THE FOOTPRINT

The same person, eating differently. Guideline eating is nearly resource-neutral — and needs more water. The big movements all run through the animal rows above.

Diet pattern Agricultural land
(acres/person/yr)
Freshwater
(gal/person/yr)
Diet GHG
(kg CO₂e/person/yr)
Reading
Current U.S. diet 1.92 94,270 1,819 The baseline everywhere on this page. ERS ERR-273 · Heller & Keoleian
DGA "Healthy U.S.-Style" 1.86 (−3%) 108,931 (+16%) 1,812 (−0.4%) Healthier, not greener: more fruit, veg & dairy means more irrigation in the arid West. ERS ERR-273
Half the animal products n.a. n.a. 1,189 (−35%) Heller & Keoleian scenario 3. U-M CSS20-01
Half the animal products + 90% less beef n.a. n.a. 891 (−51%) Cutting beef specifically doubles the effect of cutting animal foods generally. U-M CSS20-01
EAT-Lancet reference diet 0.57–0.96 (−49 to −70%) n.a. ≈947 (−68%)* Mostly-plant pattern with 14 g/day red meat; the range depends on how much of that is beef. EAT-Lancet × Poore & Nemecek
Vegetarian (lacto/ovo) 0.32–0.35 (−82%) n.a. n.a. Peters et al.: this land footprint would let U.S. farmland carry 807 million people vs 402 million on the current diet. Peters et al. 2016, Elementa

*GHG for EAT-Lancet is computed on the Poore & Nemecek basis so the ratio against the current diet is internally consistent (2,919 → 947 kg); on that same basis the current diet reads 2,919, not 1,819 — the two columns are anchored to Heller's U.S.-specific values, and only percent changes should be carried across. Water n.a. rows: no published U.S. water attribution exists for those patterns — a flagged gap, not a zero.

SCALE IT UP

The same per-capita basis, multiplied honestly: a household of four, a small town, a city, a metropolis. Linear scalings of the sourced per-capita values — county-level self-sufficiency varies enormously around them.

Quantity1 personFamily of 4Town of 5,000City of 100,000Metropolis of 1,000,000

Land stays annual in every view (a standing footprint). Basis values and their primary sources: calories & mass — ERS LAFA; land — ERS ERR-273; water — ERR-273, EPA WaterSense, USGS FS 2018-3035; energy — ERS food-system energy; GHG — Heller & Keoleian, U-M CSS20-01.

BUILD A FACT PACK

On your way to a meeting? Pick the angles you need, and prepare a one-page fact pack — headline figures with citations attached — as a PDF.