Quick Answer
Protein style (lettuce wrap) is the go-to keto order at In-N-Out. The spread contains relish and sugar, so request mustard instead for a cleaner ingredient profile. Fries are cooked in sunflower oil. Animal style adds spread and grilled onions - both contain added sugars.
In-N-Out Keto Ingredients That Matter
The company keeps its ingredient list short by fast food standards. No freezers, no preservative laundry lists on the beef. That is genuinely unusual in the category. Still, short ingredient lists are not automatically low-carb, and a few items in the default build shift the PQ Score significantly depending on how you order.
A PQ Score is CleanKeto's ingredient quality metric. It analyzes what is actually in a food — the additives, refined components, and added sugars — not just the macros on a calorie label. A higher score reflects a cleaner ingredient profile. Here is what drives that score up or down at In-N-Out.
Beef patty. Fresh, never frozen, no fillers or binders reported. A beef patty in ingredient quality terms is protein, fat, and trace minerals. Ingredient analysis scores this component well. The single patty is 2 ounces, the Double Double uses two. Neither contains carbohydrates in meaningful amounts.
Bun. Standard hamburger bun made with enriched wheat flour, sugar, and soybean oil. This is the first and most important swap: protein style replaces the bun with a lettuce wrap and eliminates the refined flour, bun sugar, and soybean oil in a single request. No upcharge.
Spread. Most people underestimate this one. In-N-Out's spread is a Thousand Island-style sauce containing mayonnaise, ketchup, and sweet pickle relish. Sweet relish contains added sugar. Ketchup contains high fructose corn syrup in most commercial formulations. Two tablespoons of this spread add an estimated 3-5 grams of carbohydrate to the order, and it is applied by default to every burger unless you say otherwise. This is the single biggest ingredient quality concern in a standard build.
Mustard. A clean substitution. Yellow mustard is water, vinegar, mustard seed, turmeric, and salt. No added sugar, no soybean oil, negligible carbohydrate. Ingredient analysis scores mustard consistently well. It also works on the burger — ask for it and most staff do not blink.
American cheese. Processed cheese with milk solids, sodium citrate, and salt. Not a whole-food ingredient, but the carbohydrate contribution is under 1 gram per slice. The sodium content is notable if sodium is a consideration for your health profile. Including or skipping the cheese does not dramatically shift the PQ Score either direction.
Lettuce and tomato. Whole vegetables with no processing concerns. Tomato carries roughly 2-3 grams of natural sugars per slice, which ingredient analysis treats differently than added sugar. Both score well.
Grilled onions (animal style). This is where animal style goes sideways for in n out low carb orders. In-N-Out grills their onions in spread, not plain oil, during the animal style preparation. That means the grilled onions themselves pick up added sugar from the sauce. Raw onions on a standard build are a different story — mild carbohydrate contribution, no added sugar, no processing concerns.
Sunflower oil (fries). In-N-Out has cooked fries in 100% sunflower oil since 1992. The oil itself is free of trans fats and blends well in ingredient quality analysis. The fries are not a fit for a strict in n out keto order regardless, because the potato base delivers roughly 54 grams of total carbohydrate in a standard serving. The oil is incidental to that load.
Ketchup packets. Contain high fructose corn syrup and added sugar. Skip them.
How to Order Keto at In-N-Out
Five steps. Follow them in order and the resulting burger scores in the 55-70 PQ range based on ingredient analysis.
1. Order protein style. Say it by name. Every In-N-Out employee knows what protein style means. The bun comes off, a large romaine-style leaf goes on the outside, and the burger gets wrapped in paper. This eliminates enriched wheat flour, bun sugar, and soybean oil.
2. Drop the spread explicitly. Do not assume it will be omitted because you ordered protein style. It is a separate instruction. Say "no spread." If you want to be thorough, say "no spread, no sauce."
3. Add mustard. Ask for mustard as a direct substitution. This keeps the burger from being dry and replaces the sugar-laden spread with a zero-sugar condiment. The staff handle this request every shift.
4. Specify raw onions if you want onions. Grilled onions on a standard build are fine. Grilled onions animal style are cooked in spread and carry added sugar. If you want onion flavor without the added sugar, ask for raw onions specifically.
5. Skip fries and soda. Water, black coffee from their limited offerings, or unsweetened iced tea keeps the order clean. If someone else at the table orders fries and you take a few, the sunflower oil is not the concern — the starch is.
Your complete order: "Double Double, protein style, no spread, add mustard, raw onions, extra lettuce." That is a clean in n out burger ingredients configuration by any ingredient quality standard.
In-N-Out on CleanKeto has a full breakdown of every item on their menu, including modifier combinations and how each one shifts the ingredient quality profile.
Key Takeaways
> Before your next grocery run: CleanKeto's PQ Score shows you exactly what is in the ingredient list, not just the macros. iOS | Android
- Protein style removes the bun entirely, costs nothing extra, and is understood immediately by every In-N-Out employee — it is the single most impactful swap available on the menu.
- Dropping the spread is a separate instruction from ordering protein style; the sauce is applied by default and will appear unless you explicitly say otherwise.
- Mustard replaces the spread without adding sugar, soybean oil, or carbohydrate, and it works well with the fresh beef patty.
- Animal style grilled onions are cooked in spread during preparation, not plain oil, which means they carry added sugars even though plain grilled onions at home would not.
- Clean keto refers to prioritizing whole, minimally processed ingredients over simply hitting macros — and by that standard, the protein style Double Double with mustard qualifies, while the standard build with spread does not.
What the Data Shows
USDA FoodData Central data on sunflower oil (linoleic type) shows a fatty acid composition of approximately 65% linoleic acid, 20% oleic acid, and under 15% saturated fat. In ingredient quality analysis, the frying medium is evaluated separately from the food being fried. At In-N-Out, the oil clears the ingredient quality bar clearly. The potato starch in the fry is the separate variable that makes fries a mismatch for in n out low carb ordering regardless of oil type.
For the beef patty, USDA FoodData Central data on 80/20 ground beef shows approximately 17-20 grams of fat per 100 grams cooked and a protein contribution of roughly 19-22 grams per quarter-pound patty. Zero carbohydrate in the beef itself. When combined with lettuce, tomato, raw onion, mustard, and a slice of American cheese — the full protein style order with no spread — ingredient analysis of the complete build typically produces PQ Scores in the 55-70 range. Add the spread and animal style grilled onions, and the score drops to the 30-45 range as added sugar moves earlier in the combined ingredient list.
The Dine Out feature on CleanKeto runs this same ingredient analysis across 273 pre-scored chains, so you are not recalculating at each restaurant from scratch.