Which Fish is Low in Sugar and Best for Your Health?

November 8, 2025 •

3 min read

According to the USDA, almost all types of fish and seafood contain virtually no carbohydrates, and therefore, no sugar. This makes them an excellent protein source for managing blood sugar and following low-carb diets. While fish naturally contains no sugar, knowing which varieties are best for overall health is key for a balanced diet.

Quick Summary

Fish is a nearly carbohydrate-free protein source, making it naturally low in sugar. This article outlines the best fatty and lean fish options, such as salmon, sardines, cod, and tilapia, detailing their nutritional benefits like omega-3s and high protein content. It also offers advice on preparation methods and fish to limit, ensuring optimal health.

Key Points

All Fish are Low in Sugar: Fish is primarily a protein source with virtually no carbohydrates or sugar, making it an excellent food for blood sugar management.
Fatty Fish Provide Omega-3s: Oily fish like salmon and sardines are rich in omega-3 fatty acids, which reduce inflammation and support heart and brain health.
Lean Fish Offer Low-Calorie Protein: White fish such as cod and tilapia are lower in calories and fat, providing lean protein and essential nutrients.
Preparation Matters: Healthy cooking methods like baking, grilling, or steaming are best, while frying or breading adds unnecessary carbs.
Choose Low-Mercury Options: Limit large, predatory fish like swordfish and king mackerel due to higher mercury levels; smaller fish are generally safer.
Incorporate Variety: Aim for at least two servings of fish per week, alternating between fatty and lean types to maximize nutritional benefits.

What Makes Fish Naturally Low in Sugar?

Fish is composed of protein and fats, with little to no carbohydrate content. Carbohydrates are the primary source of sugar in most foods, and since fish lacks them, it doesn't cause a spike in blood glucose levels after consumption. This low glycemic impact is a significant advantage for individuals managing diabetes or adhering to a low-sugar or ketogenic diet. Protein, a major component of fish, also plays a crucial role by promoting a feeling of fullness, which helps prevent overeating and managing weight, a key factor in controlling blood sugar.

Lean Fish vs. Fatty Fish: A Nutritional Overview

Fish can be broadly categorized into two types based on their fat content: lean and fatty. Both are naturally low in sugar but offer different nutritional profiles. Lean fish, like cod and tilapia, are lower in calories and fat, while fatty fish, such as salmon and mackerel, are packed with heart-healthy omega-3 fatty acids. While both are excellent choices, the best fish for you depends on your dietary goals.

The Best Low-Sugar Fish Choices

Fatty Fish (Higher in Omega-3s):

Salmon: A powerhouse of omega-3 fatty acids (DHA and EPA), known for their anti-inflammatory properties and benefits for heart and brain health. It is also rich in vitamin D and B vitamins.
Sardines: These small, nutrient-dense fish are high in omega-3s, calcium, and vitamin D. Canned sardines are a budget-friendly and convenient option, but look for low-sodium varieties.
Mackerel: Similar to salmon and sardines, mackerel is a great source of protein, omega-3s, and vitamin B12.
Herring: An excellent, often overlooked, source of vitamin D and heart-healthy fats.

Lean Fish (Lower in Calories and Fat):

Cod: This white fish is a great source of lean protein, vitamin B12, and selenium. It has a mild flavor and versatile texture.
Tilapia: A very lean, high-protein fish with a mild taste that makes it a good entry point for those new to seafood. It is also a source of selenium.
Tuna: Whether fresh or canned, tuna offers significant protein with low carbs. Look for light canned tuna, which typically has lower mercury levels than albacore.
Halibut: A firmer, white fish that is a good source of protein, magnesium, and phosphorus.

How to Prepare Low-Sugar Fish Dishes

The preparation method is crucial for keeping your fish dish low in sugar and carbs. Avoid breading or frying, which add unnecessary carbohydrates.

Baking: Place fillets on a baking sheet with vegetables like broccoli or bell peppers for a simple, healthy meal.
Grilling: Season your fish with herbs, spices, and a squeeze of lemon juice, then grill until cooked through.
Steaming: This method preserves the fish's delicate flavor and nutrients.
Pan-searing: Cook fish in a skillet with a bit of olive oil and garlic for a quick, flavorful option.

Comparison of Popular Low-Sugar Fish


Feature	Salmon	Cod	Tilapia	Mackerel
Fat Content	Higher (Fatty)	Very Low (Lean)	Low (Lean)	Higher (Fatty)
Omega-3s	Very High	Low-Moderate	Low	High
Flavor	Rich, distinct	Mild, flaky	Very mild, white fish	Rich, oily
Cost	Higher	Moderate	Low	Low-Moderate
Key Nutrients	Omega-3s, Vitamin D, B12	B12, Selenium	Selenium, Lean Protein	Omega-3s, B12, Protein
Mercury Risk	Low-Moderate	Low	Low	Moderate (King Mackerel is high, Atlantic is lower)

Fish to Limit and Considerations

While most fish is low in sugar, some varieties are higher in mercury, a toxin that can impact blood sugar control and neurological health. Limit your intake of larger predatory fish like shark, swordfish, king mackerel, and tilefish. When choosing canned tuna, opt for light tuna over albacore due to its lower mercury content. For canned fish, check labels to avoid those packed in oil or with high sodium.

Conclusion: Making the Best Low-Sugar Fish Choices

Fish is an excellent, naturally low-sugar protein that offers immense health benefits, particularly for managing blood sugar and promoting heart and brain health. Incorporating a variety of both fatty fish like salmon and sardines for their high omega-3 content and lean fish like cod and tilapia for their lower fat and calorie profile is ideal. By choosing healthy, low-sugar preparation methods and being mindful of mercury levels, you can make fish a delicious and nutritious staple in your diet.

For more information on the health benefits of omega-3s, visit the Mayo Clinic.(https://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/omega-3/art-20045614)

Frequently Asked Questions

Yes, nearly all fish and shellfish are naturally low in carbohydrates and therefore contain virtually no sugar. This applies to both fatty fish like salmon and lean fish like cod.

Fatty fish like salmon, mackerel, sardines, and herring are among the best sources of omega-3 fatty acids.

Both are healthy, but they offer different benefits. Fatty fish provides more omega-3s, while lean fish is lower in calories and fat. Incorporating both into your diet offers a wider range of nutrients.

Salmon, tilapia, mackerel, cod, and sardines are all excellent choices for managing diabetes due to their high protein, healthy fats, and low glycemic impact.

Yes, certain large, predatory fish, like shark and swordfish, have high mercury levels. It is best to stick to smaller fish like salmon, sardines, and canned light tuna, which are lower in mercury.

Yes, canned tuna and salmon are low in sugar, provided you choose varieties packed in water and with no added sugar or high-sodium marinades.

While fish is very healthy, most experts recommend eating at least two servings per week, particularly fatty fish, to receive heart-health benefits. Varying your protein sources is always a good practice.