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LINE VS LINE · NULO KIBBLE

Nulo FreeStyle vs Nulo Challenger

Nulo FreeStyle vs Nulo Challenger: a bag from each line with their average protein, fat, starch and calories

Nulo FreeStyle against Nulo Challenger, measured across 15 and 5 kibble recipes: 30.6% vs 34.4% protein and 33% vs 28% starch, as fed.

15 kibble recipes reviewed 5 kibble recipes reviewed
THE SHORT VERSION

Main Differences

  • Nulo Challenger recipes average 34.4 percent protein as fed, higher than Nulo FreeStyle's 30.6 percent average.
  • Fat is close between the two lines: Nulo FreeStyle averages 15.8 percent as fed and Nulo Challenger averages 17.2 percent.
  • Estimated starch runs higher in Nulo FreeStyle, averaging 33 percent, compared to an estimated 28 percent average in Nulo Challenger.
  • Nulo FreeStyle is 100 percent grain-free across its 15 recipes, while Nulo Challenger is 0 percent grain-free across its 5 recipes. Nulo FreeStyle also covers Adult, Puppy and Senior life stages plus Small, Large and All Breed sizes, while Nulo Challenger covers only Puppy by life stage along with All Breeds, Large Breed and Small Breed sizes.
  • Nulo FreeStyle has an estimated median price per pound of $3.57, and Nulo Challenger has an estimated median price per pound of $4.42.
HEAD TO HEAD

The Two Lines in Figures

Measure Nulo FreeStyle Nulo Challenger Average kibble
Kibble recipes compared 15 5 1,747 in total
Protein, as fed 30.6%28.0% to 33.0% 34.4%32.0% to 35.0% 27.2%
Fat, as fed 15.8%7.0% to 18.0% 17.2%14.0% to 18.0% 14.3%
Starch, as fedEstimated, not measured. It is what is left of the guaranteed analysis once protein, fat, fiber and moisture are taken out, with ash assumed at 6%. That leftover is mostly starch but also carries sugars and the fiber a crude-fiber test misses, so read it as a close estimate rather than an exact figure. Measured as fed, the same basis as the bag. 33%29% to 41% 28%27% to 33% 37%
Calories per cup 406339 to 434 425410 to 438 398
Grain-free recipes 100% 0%
Life stages Adult 6, Puppy 3, Senior 1 Puppy 1
Breed sizes All Breeds 11, Small Breed 3, Large Breed 1 All Breeds 3, Large Breed 1, Small Breed 1
Price per pound, estimate $3.57/lbEstimate, median of 15 of 15 recipesRecipes run $3.00 to $5.00Prices checked Sep 28, 2026 to Oct 6, 2026 $4.42/lbEstimate, median of 5 of 5 recipesRecipes run $4.42 to $5.00Prices checked Sep 28, 2026
FDA recalls, last 5 years None None

Line figures are averages over every kibble recipe we review from that line, with the lowest and highest recipe underneath. Wet food, toppers and prescription diets are left out so the numbers compare like with like. Everything is as fed, the way the bag prints it; the switch above the table shows protein and fat on a dry matter basis instead. Why we use as fed. The price per pound is an estimate: the median of each recipe's lowest price per pound across the bag sizes and US retailers our price checks found, so a single bag can cost more or less. Shelf prices change often.

WHERE TO START

Top Recipes in Each Line

Nulo FreeStyle

Nulo FreeStyle Turkey & Sweet Potato Recipe Grain-Free Dry Dog Food Most protein in the line, 33.0% as fed Nulo FreeStyle Turkey & Sweet Potato Recipe Grain-Free Dry Dog Food Protein 33% Fat 18% Starch 29% 424 kcal/cup Nulo FreeStyle Limited+ Salmon Recipe Grain-Free Dry Dog Food Least starch in the line, about 31% Nulo FreeStyle Limited+ Salmon Recipe Grain-Free Dry Dog Food Protein 30% Fat 18% Starch 31% 413 kcal/cup Nulo FreeStyle Adult Trim Cod & Lentils Recipe Grain-Free Dry Dog Food Fewest calories in the line, 339 kcal per cup Nulo FreeStyle Adult Trim Cod & Lentils Recipe Grain-Free Dry Dog Food Protein 30% Fat 7% Starch 41% 339 kcal/cup

Nulo Challenger

Nulo Challenger Organic Ancient Grains Haddock, Salmon & Acadian Redfish Recipe Dry Dog Food Most protein in the line, 35.0% as fed Nulo Challenger Organic Ancient Grains Haddock, Salmon & Acadian Redfish Recipe Dry Dog Food Protein 35% Fat 18% Starch 27% 427 kcal/cup Nulo Challenger Small Breed Organic Ancient Grains Haddock, Salmon & Acadian Redfish Recipe Dry Dog Food Least starch in the line, about 27% Nulo Challenger Small Breed Organic Ancient Grains Haddock, Salmon & Acadian Redfish Recipe Dry Dog Food Protein 35% Fat 18% Starch 27% 427 kcal/cup Nulo Challenger Organic Ancient Grains Duck, Turkey & Guinea Fowl Recipe Dry Dog Food Fewest calories in the line, 423 kcal per cup Nulo Challenger Organic Ancient Grains Duck, Turkey & Guinea Fowl Recipe Dry Dog Food Protein 35% Fat 18% Starch 27% 423 kcal/cup
CHOOSING

Who Each Line Suits

A GOOD FIT FOR

Nulo FreeStyle

  • Owners of senior dogs, from the Senior Trout & Sweet Potato recipe
  • Owners seeking a grain-free kibble, since Nulo FreeStyle is 100 percent grain-free
  • Owners of small or large breed puppies, covered by dedicated Small Breed and Large Breed Puppy recipes
A GOOD FIT FOR

Nulo Challenger

  • Owners wanting higher protein, since Nulo Challenger recipes average 34.4 percent protein as fed
  • Owners of large breed puppies, served by the Large Breed Puppy Organic Ancient Grains recipe
  • Owners not seeking a grain-free food, since Nulo Challenger is 0 percent grain-free
THE WHOLE RANGE

Every Nulo Line

Line Kibble recipes Protein Fat Starch Kcal / cup Grain-free Price / lb, est.
MedalSeries 25 30.2% 15.5% 34% 425 84% $3.37
FreeStyle 15 30.6% 15.8% 33% 406 100% $3.57
Frontrunner 6 27.0% 16.0% 37% 431 0% $2.82
Challenger 5 34.4% 17.2% 28% 425 0% $4.42
Culinary Harvest 5 30.0% 15.0% 35% 423 0% Not available
Nulo 5 30.0% 15.8% 33% 407 0% $4.35

Averages over each line's kibble we review, as fed. Lines with only a few recipes swing more on one bag. Price per pound is the same estimate as above.

KEEP COMPARING

More Nulo Line Comparisons

Nulo MedalSeries vs Nulo FreeStyle Nulo MedalSeries vs Nulo Frontrunner Nulo MedalSeries vs Nulo Challenger Nulo FreeStyle vs Nulo Frontrunner Nulo Frontrunner vs Nulo Challenger

The Nulo Lines

All Nulo food Nulo MedalSeries Nulo FreeStyle Nulo Frontrunner Nulo Challenger Nulo Culinary Harvest Nulo Nulo

Nulo Against Other Brands

Nulo vs Orijen Nulo vs Acana

How we compare: every figure comes from the guaranteed analysis and ingredient list of recipes we review, not from the brand's own claims. Starch is our estimate, since no manufacturer prints it. The written comparison is drafted from these figures, and every number in it is checked against them. Figures refreshed October 25, 2026.

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