The Highest-Protein Fruit Is a Coin Toss

Raw lemon flesh leads our fruit ranking at 3.79g of protein per 100 calories, and raw guava is second at 3.75g. That is a gap of 0.04g per 100 calories — about 1% — across the 33 foods USDA FoodData Central files under Fruits and Fruit Juices (lemon is FDC 167746, guava FDC 173044). Rank the same 33 per 100g instead and guava wins outright at 2.55g against lemon's 1.1g.

So there is a winner, and it changes with the basis, and at the top the gap is smaller than the precision the source figures are reported to: USDA gives lemon's protein as 1.1g per 100g, to two significant figures, and anything from 1.05g to 1.15g rounds to that — a range that straddles guava's 3.75g per 100 calories in both directions. A 1% gap is not an ordering. It is a tie with a rounding error.

The bigger problem: the whole category is below the question

Forget which fruit wins for a moment and look at the range. The distance from the best fruit to the worst is 3.50g of protein per 100 calories — lemon at 3.79g down to raw fuji apple at 0.29g. The distance from the best fruit to ordinary raw broccoli, at 8.29g per 100 calories, is 4.50g. The gap between fruit and the next shelf over is larger than the entire spread inside fruit.

Put the anchors next to each other and the ranking stops looking like a ranking:

Every figure above is protein divided by calories from the same USDA row, computed the same way. The best fruit in the set does not reach half of raw broccoli.

All 33 fruits, ranked per 100 calories

The last column is how much fruit 100 calories actually is — the number that decides whether a per-calorie figure means anything.

What the basis change actually does to this list

Switching from per 100g to per 100 calories moves almost every fruit, and the biggest movers are the ones you would predict from their calorie density — but the size of the moves is worth seeing. Dates fall 28 places, from second per 100g to thirtieth per 100 calories. They carry 2.45g of protein per 100g, more than every fruit except guava, and 282 calories with it (FDC 171726). Avocado falls 21 places, banana 15.

Going the other way, limes rise 15 places, strawberries and watermelon 14 each, cantaloupe 12. None of those four reaches 1g of protein per 100g.

The per-calorie column is the more honest one for comparing foods you eat in similar amounts, and it is the more misleading one here — because 100 calories of lemon is 345g of peeled flesh and 100 calories of dates is 35g. We are not going to convert 345g into a number of lemons: our data holds no per-fruit weights, and inventing one would be the easiest way to put a wrong number in your head.

So what is the honest answer?

If someone asks which fruit has the most protein, the defensible answer has three parts: guava per 100g at 2.55g, lemon per 100 calories at 3.79g, and the caveat that no fruit is a protein source at all. Guava is the one worth naming if you only get one word, because it wins one column outright and finishes second in the other by 1%, and 147g of it is a portion a person eats.

What none of the 33 will do is move a protein target. At guava's 2.55g per 100g, a 150g serving contributes under 4g. That is a rounding error against a typical daily figure — see how much protein you actually need for what the target looks like. Fruit earns its place on fibre, potassium and the fact that people actually eat it. Protein is not on that list, and no ranking within the category changes it.

Two limits of this table, stated rather than hidden

USDA calls the category "Fruits and Fruit Juices" and our 33 rows contain no juice. Every row here is whole fruit, and all but dates are raw. A ranking that included juices would look different, and we are not going to describe one we have not computed.

Second, every figure is for the state the USDA row describes — raw, weighed before any preparation, and for lemon specifically the flesh without peel. Dried fruit is a different food with different numbers; dates are the only concentrated entry in this set, and they are also the one that most changes rank between the two columns.

The pattern worth remembering

When the top two entries of a leaderboard are 1% apart and the whole field sits below the next category down, the ranking is answering a question that does not have a useful answer. The right move is not a better fruit. It is to stop sourcing protein from fruit and check whether the day actually landed where you wanted it.

And that last part is where a leaderboard stops helping. Looking up which fruit wins takes ten seconds. Keeping a running protein figure across a real day — the breakfast you ate standing up, the thing you grabbed between meetings — is the tedious bit, and it is the reason most people quit tracking inside a fortnight. Sunn keeps that total for you over WhatsApp: photograph the bowl or type "guava and greek yogurt", and you get the day's number back without opening an app.

Related: we ran this ranking across all 189 foods in our dataset, asked the same question of vegetables (where the winner turns out to be a fungus), published guava's complete macro breakdown, and put dates head-to-head with bananas.