Is Canned Tuna OK for a Keto Diet? The Definitive Guide

November 6, 2025 •

4 min read

According to the Food and Drug Administration (FDA), canned light tuna is a low-mercury option and a lean protein source that can be part of a healthy diet. For those on a ketogenic diet, canned tuna offers a convenient and affordable way to meet protein goals while keeping carbohydrates extremely low.

Quick Summary

This comprehensive guide explores the nutritional benefits of canned tuna for a ketogenic diet, explains the key differences between water-packed and oil-packed varieties, and provides practical advice on preparing safe and delicious low-carb meals.

Key Points

Yes, canned tuna is keto-friendly: Standard canned tuna is very low in carbs and high in protein, making it an ideal food for the ketogenic diet.
Oil-packed vs. Water-packed: Choose oil-packed tuna for higher fat intake to meet your keto macros, or water-packed for a leaner protein option.
Beware of flavored versions: Always check the label of flavored tuna pouches for hidden sugars, starches, or unhealthy oils that could increase the carb count.
Be mindful of mercury: Stick to canned light tuna more often than albacore and follow the FDA's recommended intake to limit mercury exposure.
Versatile meal base: Canned tuna can be used for a variety of quick keto meals, including tuna salad, patties, stuffed avocados, and lettuce wraps.
Enhance with healthy fats: Add avocado oil mayo, avocado, or cheese to water-packed tuna to boost healthy fat content for your keto plan.
Balance with low-carb veggies: Pair your tuna dishes with celery, onion, bell peppers, or lettuce to add fiber and micronutrients.

Canned Tuna Nutrition and How It Fits Keto

Canned tuna is a high-protein, low-carb staple that fits perfectly into a ketogenic diet. Its macronutrient profile—rich in protein and typically very low in carbohydrates—makes it an excellent choice for maintaining ketosis. The primary difference lies in how it is packed, either in water or in oil, which significantly affects its fat and calorie content. Light tuna, such as skipjack or yellowfin, is generally lower in mercury than albacore tuna, making it a safer choice for more frequent consumption.

Beyond its favorable macros, canned tuna is a nutrient-dense food. It provides a natural source of omega-3 fatty acids, which are essential for reducing inflammation and supporting heart and brain health. It is also a good source of selenium, a mineral vital for immune system function, and Vitamin D, which supports bone health. For busy keto dieters, canned tuna offers a quick, affordable, and shelf-stable source of quality protein that can be used in a variety of dishes.

Water-Packed vs. Oil-Packed Tuna for Keto

When selecting canned tuna, the choice between water-packed and oil-packed is crucial, especially for those managing their fat intake on keto. While both are low-carb, their fat content and nutritional profiles differ substantially. Oil-packed tuna, especially those using healthy fats like olive oil, can help increase your fat macros for the day, which is a key part of the ketogenic diet. However, some brands use lower-quality, inflammatory oils like soybean oil, which is best to avoid. Water-packed tuna is a leaner option, providing a significant protein boost without the added fat.

Comparison: Canned Tuna in Water vs. Oil


Feature	Tuna in Water	Tuna in Oil	Best for Keto When...
Fat Content	Lower	Higher	Higher fat intake is needed.
Calories	Lower	Higher	More calories are desired.
Macros	Leaner protein source	Higher fat for macros	Filling fat requirements.
Keto Adaptability	Excellent	Excellent	Either can be used, depending on macro needs.
Added Ingredients	Often just water and salt	Various oils (olive, sunflower, soybean)	Using olive oil-packed, or draining oil.
Nutritional Benefit	High protein, lower calories	High fat, higher calories, more omega-3s	Seeking higher caloric density and fat.

Potential Concerns: Mercury and Additives

One of the most common concerns with canned tuna is its mercury content. As a larger predatory fish, tuna accumulates more mercury than smaller fish. The FDA recommends limiting intake to 2-3 servings of canned light tuna per week, and no more than one serving of albacore tuna per week, to manage mercury exposure. Choosing smaller, wild-caught species like skipjack, often used for canned light tuna, can help minimize risk. Some brands even test each can for mercury content, offering an extra layer of reassurance.

It's also vital to read ingredient labels for unexpected additives. While most canned tuna is just fish, water/oil, and salt, some flavored varieties contain added sugars, modified starches, or unhealthy oils that could interfere with ketosis. Sticking to plain, unflavored canned tuna is the safest bet for maintaining a low-carb intake. Using your own healthy keto ingredients, like mayonnaise made with avocado oil, to create tuna salad is a better strategy.

Delicious Keto Canned Tuna Recipes

Canned tuna is incredibly versatile and can be transformed into many quick and satisfying keto meals. Here are some popular ideas:

Keto Tuna Salad: Mix canned tuna with mayonnaise (check for low-carb ingredients), finely chopped celery, and a squeeze of lemon juice. Serve it on lettuce wraps, cucumber slices, or stuffed into avocado halves.
Tuna Melts (Keto-Style): For a warm meal, combine tuna salad with shredded cheddar cheese. Serve it on low-carb keto bread or bake in avocado halves until the cheese is melted and bubbly.
Tuna Patties: Mix drained canned tuna with a binder like almond flour or crushed pork rinds, an egg, and some spices. Pan-fry them in avocado oil or butter for a crispy, satisfying meal.
Stuffed Bell Peppers: Hollow out bell peppers and fill them with a tuna salad mixture. Bake until the peppers are soft and the filling is warm.
Spicy Tuna Cucumber Bites: Spoon a spicy tuna salad (with sugar-free hot sauce) onto thick cucumber slices for a refreshing, low-carb appetizer.

Conclusion

In conclusion, canned tuna is an excellent, budget-friendly, and convenient food for those on a ketogenic diet, provided you make smart choices. Its high protein and low-carb nature make it a perfect fit for maintaining ketosis. The key is to be mindful of the packing liquid—choosing oil-packed for higher fat intake or water-packed for a leaner protein source—and to be aware of the mercury content, especially with albacore. By prioritizing low-mercury options, reading labels carefully, and getting creative with your recipes, canned tuna can be a regular and delicious part of your keto meal plan.

Important Considerations

Here are some key takeaways and tips for incorporating canned tuna into your ketogenic diet successfully:

Prioritize Light Tuna: Choose canned light tuna (typically skipjack or yellowfin) for more frequent consumption due to its lower mercury content compared to albacore.
Consider Healthy Fats: If you're looking to boost your fat macros, opt for tuna packed in extra virgin olive oil. Alternatively, add healthy fats yourself to water-packed tuna with keto-friendly mayo or avocado oil.
Read Labels Closely: Be vigilant about checking labels on flavored tuna pouches, as they can sometimes contain hidden carbs, sugars, or inflammatory oils.
Monitor Intake: Pay attention to the FDA's guidelines on fish consumption to manage your mercury intake, especially if you eat fish frequently.
Get Creative with Recipes: Use canned tuna as a base for easy keto meals like tuna salad, patties, or stuffed vegetables to add variety to your diet.
Balance with Veggies: Pair your tuna dishes with non-starchy vegetables like celery, cucumber, and leafy greens for added nutrients and fiber.

By following these guidelines, you can enjoy all the benefits of canned tuna while staying firmly within your keto dietary goals.

Frequently Asked Questions

Plain, canned light tuna in water or olive oil is best for a keto diet. Water-packed offers a leaner protein, while oil-packed provides more fat, which can help meet your macro goals. Be sure to avoid flavored pouches with added sugars.

Yes, you can eat albacore tuna on a keto diet, but it should be consumed less frequently than canned light tuna due to its higher mercury content. The FDA recommends limiting albacore to one serving per week.

Larger tuna species like albacore contain more mercury than smaller ones like skipjack. To minimize risk, choose canned light tuna more often and follow the FDA's guidelines for weekly consumption.

To make a keto tuna salad, mix drained canned tuna with a keto-friendly mayonnaise (made with avocado oil), finely diced celery, onion, and a squeeze of lemon juice. Serve it in lettuce cups, cucumber slices, or bell pepper halves.

It depends on your fat macro goals. If you need more fat, you can use the oil from tuna packed in healthy oil like olive oil. If you want a leaner protein source, drain the oil completely.

Most flavored tuna pouches should be avoided on keto as they often contain added sugars, starches, or unhealthy oils. Always check the nutrition label for the carb count and ingredients. Sticking to plain tuna and adding your own spices is a safer choice.

You can serve canned tuna with a variety of keto-friendly alternatives to bread, such as lettuce wraps, cucumber slices, celery sticks, or on top of a salad. You can also stuff it into avocado halves or bell peppers.

The FDA recommends that adults consume 2-3 servings (up to 12 ounces) of canned light tuna or up to one serving (up to 6 ounces) of albacore tuna per week to limit mercury exposure.