Is Canned Tuna a Low Carb Food? A Comprehensive Guide

December 4, 2025 •

3 min read

According to the USDA, a standard serving of canned tuna packed in water contains zero carbohydrates. For this reason, canned tuna is a widely celebrated staple for anyone following a low carb, ketogenic, or other carb-restricted eating plan. This guide explores why it's a perfect fit and what to consider when incorporating it into your diet.

Quick Summary

An in-depth look at canned tuna's minimal carbohydrate content, its high protein profile, and how it can be a valuable addition to low carb and keto meal plans. Learn about different types of canned tuna, potential added ingredients that affect carb counts, and how to prepare it to maximize its health benefits and flavor.

Key Points

Zero Carbs: Plain canned tuna (in water or oil) contains virtually no carbohydrates.
Read Labels: Check the nutritional information on flavored tuna packets, as they may contain added carbs.
High in Protein: Canned tuna is a high-protein food, which is excellent for satiety and muscle maintenance.
Nutrient-Dense: It provides essential nutrients like omega-3 fatty acids, selenium, and Vitamin B12.
Versatile Ingredient: Use canned tuna in lettuce wraps, salads, or as a base for low-carb patties.
Mercury Consideration: Be mindful of mercury levels, particularly in albacore tuna; consume in moderation.
Choose Your Packing Liquid: Water-packed tuna is lower in fat and calories, while oil-packed is higher and better for keto diets.

Understanding the Nutritional Profile of Canned Tuna

Canned tuna is primarily a source of high-quality protein and essential nutrients, with a notably low carbohydrate content. The specific nutritional breakdown can vary based on the type of tuna (light versus albacore) and the packing liquid (water versus oil), but the core carbohydrate profile remains consistently minimal. Most standard canned tuna in water or oil contains virtually zero grams of carbohydrates per serving, making it an ideal candidate for those monitoring their intake.

Beyond just being a low carb powerhouse, tuna also offers other significant health benefits. It's rich in selenium, B vitamins like B12, and heart-healthy omega-3 fatty acids, which play a role in reducing inflammation. This combination of low carbs, high protein, and healthy fats makes it a versatile ingredient for a variety of meals and dietary goals, from weight management to muscle building.

Variations in Canned Tuna: What to Watch For

While plain, canned tuna is an excellent low carb choice, consumers must be vigilant about certain flavored varieties or those with added ingredients. Some pre-seasoned or mixed tuna packets can contain added sugars, starches, or thickeners that increase the total carbohydrate count. While often still relatively low, these can add up if you are on a very strict ketogenic diet. Always check the nutrition label and ingredient list to ensure there are no hidden carbohydrates or unwanted additives.

Choosing the Right Canned Tuna for Your Low Carb Diet

Canned in Water: This is the most common and often recommended option for those focused on minimizing calories and fat. It has a cleaner flavor and keeps the carb count at zero.
Canned in Oil: Packed in oil (typically vegetable or olive oil), this version is higher in calories and fat. For those on a keto diet who need to increase their fat intake, this can be a more suitable choice.
Flavored Packets: These offer convenience but require careful inspection. Brands like StarKist offer flavored tuna creations, with some options containing as little as 1 gram of carbs, while others might be slightly higher due to added ingredients.

Making the Right Choice: Canned Tuna Comparison


Feature	Tuna in Water	Tuna in Oil	Flavored Tuna Packets
Carbohydrates	0g per serving	0g per serving	Varies (check label)
Fat Content	Very low	Higher	Varies (check label)
Calories	Lower	Higher	Varies
Best For	Weight loss, low-calorie diets	Keto diet, adding fat	Convenience, flavor variety
Consideration	Less flavor, may be drier	Higher calories, type of oil	Hidden carbs from flavorings

Mercury Levels and Safe Consumption

Another critical consideration is mercury exposure. Tuna, especially larger species like albacore (white tuna), can contain higher levels of mercury than smaller species. Health organizations typically recommend limiting albacore tuna consumption to one serving per week, while light tuna can generally be consumed two to three times weekly. These guidelines are particularly important for pregnant women and young children. For most adults, moderate consumption is perfectly safe and part of a healthy diet.

Simple Low Carb Meal Ideas with Canned Tuna

Beyond the classic tuna salad (which can be made low carb by using mayo or avocado instead of high-carb fillers), there are countless ways to enjoy canned tuna while keeping your meal keto-friendly. Here are a few ideas:

Lettuce Wraps: Mix tuna with avocado or mayo and serve in crisp lettuce cups instead of bread.
Stuffed Avocados: Halve an avocado, remove the pit, and fill the center with a flavorful tuna mixture.
Tuna Patties: Combine canned tuna with an egg and some crushed pork rinds or almond flour as a binder, then pan-fry until golden.
Tuna Melts (without the bread): Place a tuna mixture on top of a low-carb wrap or bell pepper slices and melt some cheese over it.
Salad Topping: Add a scoop of canned tuna to a large, leafy green salad with a vinaigrette dressing.

Conclusion: A Low Carb Pantry Staple

In summary, plain canned tuna, whether packed in water or oil, is undoubtedly a low carb food. Its zero-carbohydrate profile, combined with its high protein and nutrient density, makes it a valuable asset for anyone following a carb-conscious diet like keto. The key to success is to read labels carefully, especially when choosing flavored varieties, to avoid unexpected carbs. By incorporating canned tuna into simple, low carb recipes, you can enjoy a quick, affordable, and nutritious meal that supports your dietary goals. For further nutritional information, please refer to the USDA's FoodData Central website for detailed specifications.

Frequently Asked Questions

Plain canned tuna packed in water or oil typically has zero carbohydrates. However, some flavored varieties or those with added ingredients may contain small amounts of carbs, so always check the label.

For a ketogenic diet, which requires high fat intake, tuna packed in olive oil might be preferable. For those aiming to reduce calorie intake, tuna packed in water is a better choice.

While canned tuna is a healthy option, most health authorities recommend consuming it in moderation due to potential mercury levels. It's generally advised to vary your protein sources throughout the week.

Light tuna comes from smaller species and is lower in mercury. Albacore, or 'white' tuna, comes from larger fish and has a higher mercury content. Both are excellent low carb options, but albacore consumption should be more limited.

To make a low carb tuna salad, you can use mashed avocado, Greek yogurt, or a vinaigrette made with olive oil instead of traditional mayonnaise.

Many canned tuna packets are low carb, but you must check the nutritional information. Some flavors may contain added ingredients that raise the carb count, though many are still keto-friendly.

Always read the ingredient list on the label. Look out for additives like sugar, modified food starch, or other thickeners that can increase the carbohydrate content, especially in flavored varieties.