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Keto Fish: The Top 6 Fatty Fish to Eat on a Ketogenic Diet

By Liam McAuliffe M.T.S. Updated on

Table of Contents

The best fish for keto are fatty and loaded with nutrients. Keto fish provide the basis of the pescatarian keto, and Mediterranean keto diets, while offering welcome variety to standard keto and carnivores diets

Though almost all fish contain some amount of toxic compounds from pollution, the fatty fish examples here are many of the lowest toxicity types. 

Let’s explore some of the best fish for keto. 

Choosing the Best Fish for Keto

A ketogenic diet calls for consuming high-fat, low-carb, and moderate protein. When it comes keto fish, carbs aren’t a concern, but most fish are lean and high in protein. So finding the most fatty fish is key. 

A good rule of thumb is to look for keto fish that come closest to these basic keto macronutrient ranges: 

  • 70-80% of calories from fat
  • 15-30% calories from protein
  • 0-10% calories from carbohydrate

It’s worth noting, however, that you can boost the fat content of a keto fish meal by simply adding a couple tablespoons of butter, ghee, tallow, and coconut oil. 

Luckily for keto dieters, the best fish for keto are also some of the most accessible varieties of fish anywhere. In fact, 5 of the top six options can be found in canned form. 

Nutrition info per 100g

Type of Fish Calories Fat Protein Carbs % Calories from fat % Calories from protein
#1 Atlantic Mackerel 290 20.3 27 0 63 37
#2 Farmed Arctic Char 208 12 19 0 58 42
#3 Anchovies 256 15.9 28 0 56 44
#4 Farmed Salmon 234 14 25 0 56 44
#5 Wild King Salmon 195 13 22 0 54 46
#6 Sardines 139 8 19 0 50 50

Top 6 Best Keto Fish 

1. Atlantic Mackerel

Atlantic Mackerel keto fish

In addition to healthy fats and protein, Atlantic mackerel is loaded with supernutrients like vitamin D, omega-3 fatty acids, vitamin-B and selenium. 

At 91% of your RDA in vitamin D per serving, mackerel is one of the bestfood sources of the nutrient on earth. 

Vitamin D plays a vital role in supporting your immune defenses against external invaders like viruses. And it is also regulates autimmune functions by reducing inflammatory responses that factor in heart disease and diabetes. 2

Studies also show that vitamin D is effective in reducing the severity of viral infections including COVID-19. 3

As one of the world’s most fatty fish, mackerel a single 3 oz. serving offers a whopping 2990 mg of omega-3. 

This is important because our ancestral diet had a 1:1 omega-3 to omega-6 fatty acid ratio. Yet a Standard American Diet is loaded in Omega-6 vegetable and nut oils, raising the ratio to an alarming 1:16. 

Studies show that increasing Omega-3 intake can reduce the risk of heart disease.4

Another benefit of mackerel is that it’s one of the most affordable keto fish. You can stock up on 3 lbs of canned mackerel for around $20

fatty keto mackerel

 

Nutrients in Atlantic Mackerel

Atlantic Mackerel  Amount per 3 oz.  % RDA
Fat 12g
Saturated Fat 2.6g
Cholesterol 60mg
Protein 16.2g
Vitamins
Vitamin D 546.6IU 91%
Vitamin B12  7.4µg 309%
B3 7.7mg 48%
B2 .3 26%
B6 .3mg 26%
B5 .8gm 14%
Vitamin A 453.0IU 15%
Significant Minerals
Selenium  37µg 68%
Magnesium 65mg 15%
Potassium 267mg 6.8%

2. Farmed Arctic Char

As a fatty keto friendly fish, Arctic Char is often viewed as a less expensive alternative to salmon, and a more sustainable choice when compared to farm-raised varieties. 

According to the Monterey Bay Aquarium Seafood Watch, Arctic Char gets a “Best Choice” eco-rating. While their ratings for farmed Salmon range from “Good Alternative” to “No, Thanks”. 

Arctic Char (Farmed) Amount per 3 oz.  % RDA
Fat 11g
Saturated Fat 1.9g
Cholesterol 49mg
Protein 16g
Vitamins
Vitamin B12  7.4µg 83%
B1 (Niacin) 26%
B3 8.4mg 53%
B6 .5mg 30%
B5 1gm 26%

3. Anchovies

Briny, oily, and scrumptious, these little fish can add savory dynamism to many meals. They’re also loaded in B3 and selenium while providing significant amounts of iron and hard-to-get copper. 

B3 is important for metabolizing food into useable energy, while selenium boosts heart health and thyroid function. 8 9

Like other fatty fish, anchovies are excellent sources of omega-3s. In fact, they have more omega-3 eicosapentaenoic acid (EPA) than an equivalent amount of salmon. 

This anti-inflammatory fatty acid combined with the antioxidant power of selenium has been shown to play a role in preventing tumor growth and fighting different types of cancer. 5 6 7

Nutrients in Anchovies

Anchovies (Wild) Amount per 3 oz.  % RDA
Fat 15.9g
Saturated Fat 128g
Cholesterol 61mg
Protein 28g
Vitamins
Vitamin D 103.5IU 16.5%
Vitamin K 18µg 15%
Vitamin B12  1.4µg 56%
B3 30mg 186%
B6 .3mg 24%
B2 .6mg 42%
B5 1.4mg 27%
Choline 128mg 23%
Significant Minerals
Selenium 102µg 186%
Zinc 3.6mg 26%
Potassium 816mg 21%
Calcium 348mg 38%
Iron 6.9mg 39%
Copper .4mg 57%

 

4. Farmed Salmon

Farmed salmon has a lot going for it when it comes B vitamins and omega-3 fats. It also contains more fat than wild salmon. 

We’ve found that Whole Foods offers high-quality ethically farmed norwegian salmon at a good price. 

It’s worth noting that much of this fat comes from inflammatory omega-6 fatty acids. 13 14 But not to worry, the omega 3:6 ratios in farmed salmon are still in relatively healthy proportions. One small study found that consuming farmed atlantic salmon just twice a week increased blood levels of omega-3 by 50%. 15 

Toxins and Antibiotics?

There is some concern about toxins in farmed salmon, including the potential carcinogenic substances PCBs and dioxins. However, studies show that the health benefits overshadow the risks of exposure to low levels of toxins.  16 17 

Farmed salmon are also frequently fed antibiotics to protect against the spread of disease in dense populations. However, the use of antibiotics can vary widely depending on where your salmon is farmed. 

Repeated exposure to antibiotics in food can lead to antibiotic resistance and sensitivity. 

For example, studies have found that chilean farmed salmon can contain up to 530 grams of antibiotics per 1 ton of fish. While Norwegian farmed salmon is subjected to only 1 gram of antibiotics per ton. 18 19

Farmed Salmon Amount per 3 oz.  % RDA
Fat 11g
Saturated Fat 2.6g
Cholesterol 50mg
Protein 17g
Vitamins
Vitamin B12  2.75µg 115%
B3 7.37mg 46%
B6 .54mg 42%
B5 1.3gm 26%
Significant Minerals
Selenium 20.4µg 37%

5. Wild King Salmon 

fatty keto fish king salmon

King or Chinook salmon is the largest of the species of Pacific salmon. Reaching up to 100 pounds, they provide the most fat and B vitamins of any wild salmon species with over 300% of B12  per serving. 

King salmon is also widely considered the most delicious salmon. The texture is smooth the flavor is mild

If you buy King salmon in bulk you can get it for a price competitive with far inferior fish. 

King Salmon Highlights

King Salmon (Wild) Amount per 3 oz.  % RDA
Fat 12g
Saturated Fat 2g
Cholesterol 61mg
Protein 20g
Vitamins
Vitamin B12  7.4µg 308%
B3 8.4mg 53%
B6 .3mg 21%
B5 1gm 21%
Vitamin A 453.0IU 15%
B1 .2mg 13%
B2 .2mg 13%
Vitamin E 1.5mg 10%
Significant Minerals
Selenium 31.0µg 56%
Phosphorus  208.0mg 21%
Potassium  370.0mg 10%
Magnesium 24.0mg 6%

6. Sardines

fatty keto fish sardine

Like the other fatty fish on this list, sardines are high in B vitamins, especially B12, while also providing a decent amount of vitamin D. 

Sardines along with anchovies (see above) are also a good source of copper in your keto or carnivore diet food list

You might be surprised to learn that copper plays an important role in numerous bodily functions, including: 20 21

  • producing red blood cells
  • Regulating heart rate and blood pressure
  • Assisting your body in absorbing iron
  • Preventing prostate inflammation
  • Production and maintenance of bones, connective tissue, and vital organs including your brain and heart
  • Activating your immune system
Sardines (packed in water) Amount per 3 oz.  % RDA
Fat 8.9g
Saturated Fat 2.3g
Cholesterol 52mg
Protein 18g
Vitamins
Vitamin D 50iu 20%
Vitamin B12  7.65µg 319%
B3 3.5mg 22%
B6 .105mg 8%
Choline 64.6mg
Significant Minerals
Selenium 34.5µg 63%
Phosphorus  311.28mg 44%
Potassium  290.0mg 6%
Copper .231mg 26%

Lean Fish that Will Need More Fat on Keto

This list of 5 popular fish are some of the leanest. They’re great sources of protein but will need generous additions of healthy keto fats to play a significant role in your keto diet. 

Halibut 155 3.5 30.7 0 20 79
Seabass 135 3 27 0 20 80
Cod 113 1 26 0 8 92
Tuna (Yellowfin) 150 1.5 34 0 9 91
Tuna (canned) 123 .8 27.5 1.5 6 89

Keto Fish: The Takeaway

The best fish for keto are fatty fish, and these 6 fatty keto fish options provide more fat soluble vitamins than leaner varieties. They also tend to be high in beneficial omega-3 fatty acids, important vitamin B complexes, and selenium. 

Mackerel, sardines, and anchovies also provide impressive amounts of dietary vitamin D, a crucial nutrient that many people are deficient in. 

For people on the pescatarian keto diet, these keto friendly fish will be your primary foods. While for carnivore dieters, and nose-to-tail eaters, these fatty fish provide welcome, delicious, and nutrient-packed variety.

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