How Do Pescatarian and Vegetarian Diets Differ?

Overview

Pescatarian and vegetarian diets are both plant-forward lifestyles that limit or exclude meat. The main difference? Pescatarians eat seafood, while vegetarians avoid all animal flesh.

Both diets are popular for their health benefits and environmental impact, but they vary in how they meet nutritional needs and fit different lifestyles.

Similarities Between the Two Diets

Both exclude red meat and poultry.
Both focus heavily on plant-based foods such as fruits, vegetables, legumes, nuts, seeds, and whole grains.
Both may include dairy and eggs depending on the individual.

They also often avoid animal by-products like gelatin and lard. These diets are naturally rich in fiber, vitamins, antioxidants, and minerals.

Key Difference: Seafood

Pescatarians include seafood (fish and shellfish) in their diet.
Vegetarians completely avoid meat, including seafood.

Seafood adds vital nutrients like omega-3 fatty acids (EPA & DHA), vitamin B12, iron, and vitamin D, which can be harder to absorb from plants alone.

Vegetarians may get more fiber due to relying solely on plant proteins like beans, lentils, and tofu, which support gut and heart health.

Health Benefits of Both Diets

Studies show that both vegetarians and pescatarians are likely to have:

Lower risk of cancer, especially colorectal and prostate cancer
Reduced risk of heart disease, stroke, and high blood pressure
Better blood sugar control and lower risk of type 2 diabetes
Lower levels of cholesterol and visceral fat

Pescatarians benefit further from the heart and brain-protective omega-3s in fish. These fatty acids improve insulin sensitivity, reduce inflammation, and support cognitive function.

Nutritional Risks & Considerations

For vegetarians:

Risk of vitamin B12, iron, and zinc deficiency
Calcium and protein may be low if dairy is avoided
Iron absorption is less efficient from plant sources

Tip: Pair iron-rich plant foods with vitamin C (like oranges or bell peppers) to boost absorption.

For pescatarians:

Mercury exposure from high-mercury fish (e.g., swordfish, tuna)
Cost of fresh seafood can be higher than meat

Tip: Choose low-mercury fish like salmon, trout, sardines, and herring.

Pregnant or breastfeeding individuals should follow FDA guidelines for safe seafood intake—generally 2–3 servings of low-mercury fish weekly.

Cost Comparison

Vegetarian diets can be very budget-friendly, especially with proteins like beans, lentils, and tofu.
Pescatarian diets may cost more if using fresh seafood, but frozen or canned fish can lower expenses.

Money-saving tips:

Buy grains and legumes in bulk
Use canned goods (fish, beans)
Choose seasonal produce
Cook in batches and freeze leftovers

Environmental Impact

Adopting a vegetarian or pescatarian diet can significantly reduce your environmental footprint:

Vegetarian diets produce ~35% fewer greenhouse gas emissions than meat-based diets.
Vegan diets cut them by up to 50%.
Pescatarian diets may contribute to overfishing and ocean damage if not practiced sustainably.

Tip: Use guides like Monterey Bay Aquarium’s Seafood Watch to find sustainable seafood options.

Which Diet Is Right for You?

Choose pescatarian if:

You want more nutrient flexibility
You enjoy seafood
You’re concerned about B12, iron, or omega-3 intake

Choose vegetarian if:

You want to minimize environmental harm
You don’t eat fish
You prefer a fully meat-free lifestyle

Flexitarian diets (mostly plant-based with occasional meat or fish) can also be a practical, balanced approach.

Tips for Getting Started

Start small: Go meat-free a few meals each week
Try new recipes: Swap meat for plant-based proteins or fish
Ensure protein at every meal: Use beans, lentils, tofu, eggs, dairy, or fish
Work with a dietitian to address nutrient gaps (like B12 or omega-3)

Transitioning is easier when you plan ahead and explore new, satisfying dishes.

A Quick Summary

Pescatarians eat fish; vegetarians don’t.
Both diets are rich in plant foods and can improve heart health, reduce cancer risk, and support diabetes prevention.
Vegetarian diets are more eco-friendly.
Pescatarian diets provide more bioavailable nutrients, especially for those who eat seafood.