A vegetarian who eats fish is called a pescatarian (sometimes spelled pescetarian). The term combines the Italian word “pesce,” meaning fish, with “vegetarian,” and it first appeared in English in 1991. Pescatarians skip all land-animal meat, including chicken, beef, pork, and game, but include fish and shellfish alongside the fruits, vegetables, grains, and legumes that form a typical vegetarian diet.
What Pescatarians Eat and Avoid
The core rule is simple: no meat from animals that live on land. That means no poultry (chicken, turkey), no red meat (beef, pork, lamb), and no wild game (venison, bison). Fish and seafood of all kinds are on the table, from salmon and tuna to shrimp, crab, and oysters.
Most pescatarians also eat dairy, eggs, and honey, which makes the diet closer to a lacto-ovo vegetarian pattern with the addition of seafood. A smaller number follow what researchers call a “pescavegan” approach, eating fish and plant foods but cutting out dairy and eggs entirely. There is no single rulebook, so in practice people tailor it to their own preferences.
Why People Choose This Diet
Pescatarianism tends to attract people who want the health benefits associated with plant-heavy eating but find a fully vegetarian or vegan diet too restrictive, particularly when it comes to protein and certain nutrients that are abundant in seafood. Others are motivated by environmental concerns or simply dislike the taste and texture of land-animal meat.
The environmental case is straightforward. A Polish study published in the journal Nutrients measured the daily carbon footprint of different diets and found that meat-eaters produced an average of 3.62 kg of CO₂ equivalent per day, while fish-eaters came in at 2.72 kg. Calorie for calorie, a standard meat-based diet generated about 40% more greenhouse gas emissions than a fish-inclusive one.
Heart Health and Omega-3 Benefits
The strongest health argument for pescatarianism centers on the heart. A meta-analysis of five large prospective studies, highlighted by the American College of Cardiology, found that coronary artery disease mortality was 34% lower in pescatarians compared to regular meat-eaters. Much of that advantage comes from omega-3 fatty acids, the anti-inflammatory fats concentrated in oily fish like salmon, mackerel, sardines, and herring.
Data from the Adventist Health Study-2 illustrates how much fish matters for omega-3 status. Pescatarians in that study consumed an average of 158 milligrams per day of EPA and DHA (the two omega-3s most important for heart and brain health), compared to just 10 mg for vegans and 18 mg for lacto-ovo vegetarians. Their Omega-3 Index, a measure of these fats in red blood cells, averaged 5.7%, while vegans and vegetarians both fell below 4%, well under the recommended target. In other words, simply adding fish closes a significant nutritional gap that plant-only diets struggle to fill through food alone.
Nutrients to Watch
Because pescatarians eat seafood, dairy, and eggs, they have an easier time meeting their needs for protein, vitamin B12, vitamin D, iodine, and zinc than strict vegetarians or vegans do. Fish is also one of the best dietary sources of selenium, a mineral involved in thyroid function and immune defense.
The one nutrient that requires some attention is iron. Red meat is the richest source of heme iron, the form your body absorbs most efficiently. Without it, pescatarians rely on the non-heme iron found in beans, lentils, spinach, and fortified cereals, which is absorbed at a lower rate. Pairing iron-rich plant foods with vitamin C (citrus, bell peppers, tomatoes) helps your body absorb more of it.
Mercury and Safe Fish Choices
Mercury is the main safety consideration for anyone eating fish regularly. It accumulates in larger, longer-lived predatory species and can affect the nervous system at high levels. The FDA recommends at least 8 ounces of seafood per week for adults, and 8 to 12 ounces for those who are pregnant or breastfeeding, chosen from lower-mercury options.
Seven types of fish carry mercury levels high enough that the FDA says to avoid them entirely: king mackerel, marlin, orange roughy, shark, swordfish, Gulf of Mexico tilefish, and bigeye tuna. The “best choices” category, which includes salmon, sardines, tilapia, shrimp, pollock, catfish, and canned light tuna, can be eaten two to three times per week with minimal concern. A good rule of thumb: smaller fish lower on the food chain tend to carry less mercury.
How It Differs From Other Diets
The terminology around plant-leaning diets can get confusing. Here is how the main categories break down:
- Pescatarian: No meat or poultry. Fish, seafood, dairy, and eggs are included.
- Lacto-ovo vegetarian: No meat, poultry, or seafood. Dairy and eggs are included.
- Lacto-vegetarian: No meat, poultry, seafood, or eggs. Dairy is included.
- Ovo-vegetarian: No meat, poultry, seafood, or dairy. Eggs are included.
- Pescavegan: No meat, poultry, dairy, or eggs. Fish and seafood are included.
- Vegan: No animal products of any kind.
Pescatarianism sits in a middle ground that many people find sustainable long-term. It preserves access to the nutrients most difficult to get from plants alone, particularly omega-3s and B12, while still eliminating the red and processed meats most consistently linked to chronic disease. For people who want to move away from meat without overhauling their entire relationship with food, it is one of the more practical starting points.