What is the best fish for your diet?

December 16, 2025 •

3 min read

According to the American Heart Association, eating at least two servings of fish per week, especially fatty fish, is recommended for heart health. Knowing what is the best fish for your diet, however, requires balancing nutritional benefits with concerns like mercury levels and sustainability.

Quick Summary

This article explores the nutritional profiles of various fish, comparing fatty and lean options to help you choose the best fish for your specific dietary goals, including boosting omega-3 intake, managing weight, and minimizing mercury exposure.

Key Points

Fatty vs. Lean: Fatty fish like salmon and mackerel are high in omega-3s, while lean fish like cod and tilapia are low-calorie protein sources.
Prioritize Omega-3s: For heart and brain health, aim for at least two servings of fatty fish per week, as recommended by the American Heart Association.
Choose Low-Mercury Options: To minimize mercury exposure, select smaller fish like salmon, sardines, and tilapia, and limit high-mercury predatory fish.
Consider Sustainability: Look for third-party certifications like the MSC or ASC to ensure your fish is responsibly sourced.
Incorporate Variety: A balanced diet includes both fatty and lean fish, providing a wider range of essential nutrients.

Understanding the Nutritional Difference: Fatty vs. Lean Fish

When deciding what is the best fish for your diet, it's crucial to understand the fundamental difference between fatty and lean fish. Fatty, or 'oily,' fish are rich in beneficial omega-3 fatty acids (EPA and DHA), which are essential for brain function, reducing inflammation, and maintaining heart health. Lean, or 'white,' fish are lower in fat and calories but are still excellent sources of high-quality protein and essential vitamins.

Benefits of Fatty Fish

Omega-3s: Fatty fish like salmon and mackerel are the richest dietary source of EPA and DHA, vital for brain and heart health.
Vitamin D: These fish are among the few natural food sources of vitamin D, a nutrient critical for bone health and immunity that many people are deficient in.
Weight Management: Omega-3s can play a role in regulating appetite and metabolism, supporting weight management.
High-Quality Protein: All fish provide high-quality protein, but fatty fish offer this alongside superior omega-3 benefits.

Benefits of Lean Fish

Low Calorie: For those focused on calorie restriction for weight loss, lean fish like cod and tilapia provide significant protein without high fat content.
Nutrient Rich: They are packed with essential nutrients, including selenium, niacin, and Vitamin B12.
Versatile: Their mild flavor makes them incredibly versatile for many culinary applications.

A Comparison of Popular Fish for Your Diet


Feature	Salmon	Tuna	Tilapia	Cod
Type	Fatty	Lean (canned light) / Fatty (albacore/fresh)	Lean	Lean
Omega-3s	Very High	High (albacore) / Moderate (canned light)	Low	Low
Mercury	Low	Higher (albacore/fresh) / Low (canned light)	Very Low	Very Low
Protein	High	High	High	High
Vitamin D	High	Moderate	Moderate	Moderate
Sustainability	Varies by source (check MSC)	Varies by source	Varies by source	Varies by source

Managing Mercury and Other Contaminants

For many, a key concern when choosing fish is mercury exposure. Larger, longer-lived predatory fish tend to accumulate higher levels of mercury, a neurotoxin. Predatory species like swordfish, shark, and king mackerel are on the higher end of the mercury scale, and consumption is often limited, especially for vulnerable populations like pregnant women and young children. Conversely, smaller fish lower on the food chain, such as sardines, salmon, and tilapia, generally have lower mercury levels and are safer for more frequent consumption.

Safe Choices for Frequent Consumption: Salmon, sardines, tilapia, catfish, and pollock are among the best choices for minimal mercury risk.
Wild-caught vs. Farm-raised: The nutritional profile of wild-caught versus farm-raised fish is often debated. While wild fish may have fewer contaminants, reputable farming operations have significantly improved and often provide similar nutritional value, especially in terms of omega-3s. Your best option is to look for certifications from organizations like the Aquaculture Stewardship Council (ASC) to ensure sustainable and high-quality production.

Considering Sustainability and Environmental Impact

Sustainable sourcing is an increasingly important factor in choosing seafood. Overfishing and harmful practices damage marine ecosystems. Checking for certifications from independent bodies, such as the Marine Stewardship Council (MSC) or Aquaculture Stewardship Council (ASC), helps ensure you are making an environmentally responsible choice. These labels guarantee that the fish was caught or farmed in a way that minimizes environmental harm. Selecting a variety of species from different, responsibly managed sources also helps prevent overexploitation of a single type of fish.

Conclusion: Making the Best Choice for Your Health

The best fish for your diet isn't a single species, but rather a thoughtful rotation of options that align with your health goals and personal preferences. To maximize omega-3 intake, incorporate fatty fish like salmon and mackerel into your diet 1-2 times per week. For lean, low-calorie protein with minimal mercury, prioritize white fish such as cod, tilapia, and canned light tuna. Always aim for variety and consider sourcing from sustainable providers to support your health and the planet. By weighing the benefits of fatty fish against the low-mercury advantages of lean fish, you can confidently build a healthy, balanced diet. To learn more about sustainable seafood practices, visit the Monterey Bay Aquarium's Seafood Watch website at seafoodwatch.org.

Frequently Asked Questions

Fatty fish such as salmon, mackerel, herring, and sardines are the best for omega-3 fatty acids.

Canned light tuna is a good, low-mercury option. Albacore and fresh tuna have higher mercury levels, so consumption should be limited, especially for pregnant women and children.

Yes, but some fish are much lower in mercury than others. The FDA provides guidelines on which fish have low mercury levels and can be eaten more frequently, such as salmon, shrimp, and tilapia.

Both wild and farm-raised fish offer similar nutritional value. Some wild fish may contain slightly higher levels of omega-3s, but reputable farmed fish is a safe and often more affordable option.

Baking, grilling, poaching, and steaming are healthier cooking methods than frying, which can add excessive fat and calories.

Dietary guidelines recommend eating at least two servings of fish per week, with one being an oily fish.

When sourced from reputable farms (e.g., Ecuador, Peru), tilapia is a healthy, low-mercury, and protein-rich fish. The omega-6 content is balanced, despite old rumors.