Labelgrade Data Study · Published 2026-06-07

Protein Per Calorie

The most — and least — protein-efficient packaged foods

We ranked all 356 packaged foods we've graded by a single honest number — grams of protein per 100 calories — and the leaderboard barely resembles the "high-protein" aisle: canned tuna, plain Greek yogurt, ready-to-drink shakes and whey powders deliver the most protein for the fewest calories, while a long list of "protein" bars, "power" bowls and protein-branded cereals turn out to be mostly carbs and fat wearing a protein label.

"High protein" is the loudest claim in the grocery store, and the easiest to fake. A wrapper can promise 20 grams and still be mostly sugar and fat, because grams-per-serving says nothing about what fraction of a food is actually protein. So we ranked our entire graded catalog by the number that does: grams of protein per 100 calories. The foods that win aren't the ones with the biggest front-of-pack number — they're the ones where protein, not filler, is doing the work.

How we measured it

The metric is deliberately simple: protein per 100 calories = (protein grams ÷ calories) × 100. A score of 20 means a fifth of that food's calories come from protein; a score of 5 means a twentieth. We computed it for every one of the 356 products in our catalog that has calories above zero and a protein figure on the label — out of 356 graded products in total — using the USDA-verified nutrition panel shown on each product's fact sheet. We also show protein per 100 g (a dry-weight view that flatters powders and jerky) and protein per serving (the absolute dose), because the three numbers tell different parts of the story. Every figure on this page is computed live at build time from the product pages, so nothing here can drift from the underlying data. The overall letter grade comes from our six-dimension methodology.

The most protein-efficient packaged foods

The top 20, ranked by grams of protein per 100 calories. To keep this an honest leaderboard of protein foods — not a list of condiments that happen to be nearly all protein at ten calories — we required a real protein dose of at least 8 g per serving. Each product links to its full fact sheet with the USDA numbers and the dimension-by-dimension grade.

The pattern is consistent: canned tuna and fish, plain non-fat Greek yogurt, ready-to-drink protein shakes, and whey protein powder own the top of the list. These are foods where the calories you spend are overwhelmingly buying protein — Bumble Bee Chunk Light Tuna in Water leads at 22 g per 100 calories, meaning about 88% of its calories are protein.

The protein impostors: least efficient per calorie

Now the other end — and here we hold the marketing to its own promise. Every product below puts a protein, "power," "recovery" or "sport" claim on the label (where the catalog runs short, we add foods from aisles shoppers assume are protein-friendly — granola, bars, "better-for-you" cereal), yet each delivers under 8 g of protein per 100 calories, because sugar and fat make up most of what's inside. We deliberately leave out honest non-protein foods like ketchup, jelly and soda: a condiment isn't an impostor, because it never claimed to be a protein source in the first place. 20 products in our catalog market on protein yet fall below that line; the 12 weakest are here.

A grade here isn't a verdict that the food is bad — several of these are perfectly reasonable snacks with a B. The point is narrower: they are not efficient sources of protein, and the label often implies otherwise. Healthy Choice Power Bowls Mango Edamame, for instance, leans on its protein message but lands at 2.7 g per 100 calories — roughly 8.1× less protein-efficient than Bumble Bee Chunk Light Tuna in Water at the top of the list. If you're eating it for the protein, you're mostly paying calories for sugar and fat.

Density vs. per serving: the distinction that matters

Two numbers get conflated in protein marketing, and keeping them apart is the whole game:

• Protein density (per 100 calories, or per 100 g) tells you the quality of a food's calories — how much of what you eat is protein versus filler. It's what makes tuna and Greek yogurt elite even in small portions.
• Protein per serving tells you the dose — whether one realistic portion actually moves you toward your daily target. It's why a 30 g shake can be the practical winner even if it's a hair less dense than a can of tuna.

The two don't always agree. Bumble Bee Chunk Light Tuna in Water is about as protein-dense as packaged food gets at 22 g per 100 calories, yet a single serving is only 11 g — high density, modest dose. Fairlife Core Power Elite, by contrast, delivers the biggest single hit on the leaderboard at 42 g in one serving for 232 calories. A small, ultra-dense serving can still leave you short of protein, and a large serving of a mediocre food can hit a protein number while dragging a lot of calories along with it. The best high-protein choices — the ones at the top of our list — win on both axes: dense calories and a meaningful dose per serving. When you're shopping, read both numbers, and treat the word "protein" on the front of the package as a question, not an answer.

Methodology & data

This report is generated live from the Labelgrade catalog of 356 branded foods, ranking the 356 of them that carry both a calorie and a protein figure. Protein efficiency is (protein grams ÷ calories) × 100, computed from each product's USDA-verified nutrition panel; the overall letter grade comes from our six weighted dimensions — protein density, ingredient quality, saturated fat, sodium, sugar, and fiber — detailed in full at labelgrade.com/methodology. The complete, browsable dataset — every product, every grade, every macro — is open at labelgrade.com/data.

Labelgrade is editorially independent: grades and rankings are computed from nutrition data and ingredient panels and are never influenced by affiliate relationships. See our editorial standards. Found a number you think is wrong? Our corrections policy is public, and every product page shows its USDA source.

Cite this report

These findings are free to cite and reuse with attribution to Labelgrade (labelgrade.com). Journalists, dietitians, coaches, and writers covering protein, packaged food, or nutrition marketing are welcome to use the rankings and the density-vs-dose framing above — please link to this page so readers can check the live data.

Source: Labelgrade Protein-Per-Calorie Study, labelgrade.com, 2026. Data: labelgrade.com/data · Method: labelgrade.com/methodology.

Want a specific cut — by category, a different calorie threshold, or per-dollar protein efficiency? Reach us via the contact page. This page updates automatically as the catalog grows and grades are revised; figures reflect the catalog as of the last build.