What Does It Mean When You Only Eat Fish and Vegetables?

December 2, 2025 •

3 min read

According to one 2022 study, individuals who follow a pescetarian diet have a lower risk of certain cancers compared to meat-eaters. This eating pattern, characterized by only eating fish and vegetables alongside other plant-based foods, is a popular dietary style that offers numerous health and environmental benefits.

Quick Summary

This guide explains the pescetarian diet, covering its health advantages like improved heart health and reduced risk of chronic disease. It also discusses the importance of nutrient planning, sustainable sourcing, and balancing meals for a healthy lifestyle.

Key Points

Pescetarian Diet: This eating style means consuming a primarily plant-based diet that includes fish and seafood but excludes all other types of meat and poultry.
Heart Health: The omega-3 fatty acids from fish, combined with fiber from plants, significantly reduce the risk of heart disease, lower blood pressure, and improve cholesterol levels.
Nutrient-Rich: Fish and shellfish provide essential nutrients like vitamin B12, iron, zinc, and protein, which can be challenging to obtain from a strict vegetarian diet.
Mercury Awareness: To minimize mercury exposure, it is important to select low-mercury fish like salmon, sardines, and shrimp while limiting high-mercury options such as shark and swordfish.
Lower Environmental Impact: Compared to meat-heavy diets, the pescetarian diet typically has a smaller environmental footprint due to reduced greenhouse gas emissions and less demand for land and water resources.
Balanced Approach: Success on a pescetarian diet relies on eating a wide variety of whole foods—including whole grains, legumes, and plenty of vegetables—rather than relying on processed, meat-free junk food.

Understanding the Pescetarian Diet

When a person's diet is primarily plant-based but includes fish and seafood, it's known as a pescetarian or pescatarian diet. This style excludes all other land animal meat and poultry, utilizing fish as the main animal protein source. Pescetarians eat a variety of fruits, vegetables, grains, legumes, nuts, and seeds. Some may also consume dairy and eggs, a variation referred to as lacto-ovo-pescetarianism. This dietary choice is often seen as a balanced way to gain the benefits of plant-forward eating and seafood nutrients.

Core Motivations for Pescetarianism

Health benefits, particularly for cardiovascular wellness, are a key reason people choose this diet. Environmental and ethical considerations are also influential, with many aiming to reduce their carbon footprint or viewing fish consumption as a more ethical option than eating land animals.

Health Benefits of a Fish and Vegetable Diet

A well-planned pescetarian diet can be very nutritious, combining plant micronutrients with protein and healthy fats from fish.

Improved Heart Health and Lowered Disease Risk

Rich in Omega-3 Fatty Acids: Fatty fish are high in omega-3s (EPA and DHA), which reduce inflammation, lower blood pressure, and decrease heart disease risk.
Higher Fiber Intake: Emphasizing plant foods increases fiber, supporting heart health and digestion.
Lower Saturated Fat: Avoiding red meat lowers saturated fat intake, improving cholesterol levels.
Reduced Chronic Disease Risk: Studies link this diet to lower rates of type 2 diabetes and metabolic syndrome compared to diets high in red meat.

Nutritional Adequacy

Including fish helps ensure adequate intake of protein, vitamin D, and essential minerals. Shellfish offer good sources of vitamin B12, iron, and zinc.

Potential Risks and Considerations

Planning is important to manage potential drawbacks of a pescetarian diet.

Mercury and Contaminant Exposure

Mercury Levels: Fish contain traces of methylmercury.
Choosing Safely: Limit high-mercury fish and choose low-mercury options like salmon, sardines, and shrimp. The FDA offers guidance on safe fish consumption.

Potential Nutrient Deficiencies

Iron: Obtain iron from plant sources and shellfish.
Vitamin B12: Ensure intake from fish, fortified foods, or supplements, especially if excluding dairy.

Environmental and Ethical Concerns

Sustainable Sourcing: Address overfishing by choosing sustainably certified seafood.

Pescetarian vs. Other Common Diets


Feature	Pescetarian Diet	Vegetarian Diet	Omnivorous Diet
Protein Source(s)	Fish, seafood, plants, optional dairy/eggs	Plants, optional dairy/eggs	Fish, poultry, red meat, plants, dairy/eggs
Nutrient Highlights	Omega-3s, high protein, fiber, B12	High fiber, antioxidants, vitamin C	High protein, iron, B12, saturated fat
Heart Health Risk	Generally low	Low	Potentially higher with red meat
Environmental Impact	Lower than omnivore	Lower than omnivore and pescetarian	Higher than pescetarian and vegetarian
Flexibility	High, diverse options	Moderate, fewer animal protein options	High, very diverse options

How to Transition to a Pescetarian Lifestyle

Transitioning involves replacing other meats with seafood a few days a week. Explore various fish and seafood options for nutrient diversity. Build meals around whole grains, legumes, and diverse vegetables. Choose healthy cooking methods. Resources like the Monterey Bay Aquarium Seafood Watch provide sustainable seafood information. Consider eggs, dairy, or fortified foods for added nutrients.

Conclusion

Only eating fish and vegetables aligns with a pescetarian diet, offering significant health advantages like improved heart health and reduced chronic disease risk due to omega-3s, fiber, and lean protein. Potential concerns like mercury exposure and nutrient planning can be managed by selecting low-mercury fish and varied plant foods. For many, the pescetarian diet is a sustainable, flexible, and healthy bridge between vegetarian and omnivorous diets.

Frequently Asked Questions

The main difference is that a pescetarian diet includes fish and seafood, while a vegetarian diet excludes all meat and fish.

Generally, yes. A well-balanced pescetarian diet is often lower in saturated fat and higher in heart-healthy omega-3s, leading to a reduced risk of chronic diseases compared to diets high in red and processed meats.

For optimal health and lower mercury exposure, fatty fish like salmon, sardines, and mackerel are excellent choices. Other good options include shrimp, cod, and tilapia.

It depends on the individual. Many pescetarians, sometimes called lacto-ovo-pescetarians, do include dairy and eggs, but it is not a requirement of the diet.

You can get iron from other sources, including shellfish like oysters and clams, as well as plant-based foods such as lentils, spinach, and fortified cereals.

A pescetarian diet has a lower carbon footprint than a diet that includes red meat, as the livestock industry contributes significantly to greenhouse gas emissions.

Yes, it can. The emphasis on lean protein and high-fiber plant foods can promote satiety, reduce overall calorie intake, and support healthy weight management.