The cheapest proteins cluster tighter than you think#
The budget-protein hierarchy is narrower and less exotic than the internet suggests: priced by the gram of protein rather than by the package, milk, pork, chicken, eggs, and dried legumes all land within about 60 cents of each other. Using US national retail prices, one analysis put the cost of 50 grams of protein at $1.62 for nonfat milk, $1.96 for whole milk, $2.00 for pork, $2.11 for chicken, $2.20 for eggs, and $2.22 for beans, peas, and lentils. The expensive tier is a different world — shellfish at $9.23, nuts at $6.72, and bacon at $5.38 for the same 50 grams1.
So hitting a protein target on a budget is not a puzzle with a clever answer. It is five or six ordinary foods — eggs, milk, dried legumes, canned fish, chicken, pork — none of which is dramatically cheaper than the others, and all of which are cheap. The daily target these serve is set in how much protein per day; this is about filling it for a few dollars, and about one number the SEO guides get wrong.
Cost per gram of protein, not per pack#
| Protein source | Cost per 50 g protein (US, 2017-18) |
|---|---|
| Nonfat milk | $1.62 |
| Whole milk | $1.96 |
| Pork | $2.00 |
| Chicken | $2.11 |
| Eggs | $2.20 |
| Beans, peas, lentils | $2.22 |
| Bacon | $5.38 |
| Nuts | $6.72 |
| Shellfish | $9.23 |
Two things about this table need saying plainly. First, the disclosure: it was compiled in a Perspective funded by Dairy Management Inc., the dairy industry's promotion body, and it does place the two milks at the very bottom of the cost column — exactly the conclusion the funder would want1. The underlying prices come from the USDA's Purchase to Plate national retail data, which is neutral, so the more robust reading is not "milk wins" but that milk, pork, chicken, eggs, and legumes all sit within roughly 60 cents of each other per 50 grams of protein. Treat the ordering inside that cluster as noise and the cluster itself as the finding.
Second, the correction. Budget guides love to say dried lentils are several times cheaper than chicken, and per bag that is true — a sack of dry lentils is cheap. But a food's price per pack and its price per gram of protein are different questions, because legumes are protein-dilute: cooked lentils carry roughly 9 grams of protein per 100 grams, against about 31 for cooked chicken breast. Once you price the thing you are actually buying protein for — the protein — legumes roughly tie eggs and chicken rather than crushing them. That is not an argument against legumes. It is an argument for measuring cost the way your body measures the food.
The legume bonus the price tag misses#
Legumes earn their place for a reason the cost table can't show: they are unusually filling for their calories, because they pair protein with a large dose of fiber. In a randomized crossover, 43 young men ate three meals matched for calories and protein percentage — one built on beans and peas, one on veal and pork, one a low-protein legume version. The high-protein legume meal produced higher fullness and lower hunger than the meat meal, and cut energy intake at the next meal by 12%3.
The honest mechanism is worth naming: the legume and meat meals were matched on protein and calories, so the extra fullness almost certainly came from fiber — 25 grams per 100 grams in the legume meal versus 6 in the meat one — not from the protein itself. That is exactly why legumes are a budget standout rather than merely a cheap one: you buy protein and satiety in the same low-cost package. The general reason protein fills you is in protein and satiety; the fiber layered on top is the legume's own contribution.
Plant protein is the cheap way to raise the number#
Zoom out from single foods to whole diets and the same pattern holds. In the Seattle Obesity Study, eating more plant protein barely moved food costs — the highest quartile of plant-protein intake cost about $0.35 more per day than the lowest — while shifting toward animal protein carried a steeper price, roughly $1.07 more per day across the same quartile gap. The authors concluded plant protein is a cost-effective way to improve diet quality at any income2.
The practical read is not "go vegan to save money" — it is that leaning on legumes, grains, and a little dairy is the cheapest way to push your daily protein up, and that doing so costs almost nothing extra. Whether plant protein builds muscle as well as animal protein is a separate question, answered reassuringly in plant vs animal protein: matched on total intake, it does. And the amino-acid quality of these budget foods — eggs score at the top, legumes lower but easily complemented — is ranked in the best protein sources, a shopping list organized by quality rather than by price.
A day of protein for a few dollars#
Here is what the cheap tier looks like on a plate. These are approximate protein figures per common serving4; the point is how quickly the humble foods stack toward a daily target.
| Food | Protein per serving (approx.) |
|---|---|
| 3 large eggs | ~18 g |
| 1 cup cooked lentils | ~18 g |
| 1 can tuna, drained | ~27 g |
| 1 cup low-fat cottage cheese | ~24 g |
| 1 cup 2% milk | ~8 g |
Three eggs, a can of tuna, a cup of lentils, and a cup of cottage cheese already clears 85 grams before you have touched a chicken thigh or a glass of milk — and every item on that list is in the cheapest tier of the cost table above. One quiet lever inside the meat aisle: dark-meat cuts and bone-in birds usually cost less per gram of protein than trimmed breast, so the cheapest chicken is rarely the one marketed as the leanest. A budget is rarely the real obstacle to hitting a protein target; forgetting to plan for it usually is. The satiety-per-dollar of these foods also makes them the backbone of high-protein snacks that keep between-meal hunger down.
FAQ#
What is the cheapest source of protein?#
By the gram of protein, the cheapest options cluster together: nonfat and whole milk ($1.62-$1.96 per 50 g protein), pork ($2.00), chicken ($2.11), eggs ($2.20), and dried legumes ($2.22) using US retail prices1. There is no single winner worth optimizing — pick whichever of those you will actually cook, and avoid the expensive tier of shellfish, nuts, and bacon.
Are dried lentils really the cheapest protein?#
Cheap, but not the runaway bargain the per-bag price implies. Lentils are protein-dilute (about 9 g protein per 100 g cooked), so priced per gram of protein they roughly tie eggs and chicken rather than beating them severalfold1. Their real edge is fiber-driven fullness: a legume meal cut next-meal intake 12% versus a meat meal at matched protein and calories3.
Does buying cheaper protein mean worse protein?#
No. The cheap tier includes some of the highest-quality proteins there are — eggs and milk score at the top of amino-acid quality rankings, and dried legumes complement grains to close their gaps. Price and quality are close to independent here, which is why the best protein sources and this budget list overlap so heavily.
Sources#
- Drewnowski A. Perspective: Milk and Dairy Provide Affordable High-Quality Protein and Merit Inclusion in the Protein Foods Group. Curr Dev Nutr. 2024;9(1):104539. (Funded by Dairy Management Inc.; retail prices from the USDA Purchase to Plate tool.)
- Aggarwal A, Drewnowski A. Plant- and animal-protein diets in relation to sociodemographic drivers, quality, and cost: findings from the Seattle Obesity Study. Am J Clin Nutr. 2019.
- Kristensen MD, Bendsen NT, Christensen SM, Astrup A, Raben A. Meals based on vegetable protein sources (beans and peas) are more satiating than meals based on animal protein sources (veal and pork) - a randomized cross-over meal test study. Food Nutr Res. 2016.
- USDA FoodData Central. Agricultural Research Service, U.S. Department of Agriculture.
