Most people have a rough idea of what a pescatarian diet involves: a plant-based diet with fish and seafood added in. For seafood lovers, the transition is usually easy; for committed meat-eaters, particularly those who dislike the taste or texture of fish, it can take more adjustment.
Wholegrains, pseudo-grains (like quinoa or buckwheat), nuts, nut butters and seeds are typically part of a pescatarian diet too, alongside fish and plants, though exactly how it's structured varies by individual. Limiting high-saturated-fat dairy is generally part of getting the full benefit of this way of eating. It shares some similarity with the Mediterranean diet, though the Mediterranean diet includes small amounts of lean meat, which pescatarian eating excludes entirely. If dairy and eggs are also reduced or removed, it's worth being mindful of calcium intake.
Balance matters if red meat is avoided altogether, since it's a significant source of dietary iron. Leafy greens like broccoli and spinach, along with fortified low-sugar cereals, can help make up the difference, alongside other vitamins and minerals as needed.
There are both ethical and practical considerations around a pescatarian diet, but it can be a genuinely healthy, sustainable way of eating for many people. As with any significant dietary change, it's worth discussing with a GP or dietitian first, particularly if you have existing health conditions.
What Are the Benefits of a Pescatarian Diet?
A pescatarian diet works best alongside a genuinely wide range of fruit and vegetables – the balance matters as much as the fish itself.
Heart health is one of the areas most associated with this way of eating. Fish provides omega-3 fatty acids, and despite the name, "fatty" fish refers to healthy unsaturated fats rather than anything to be concerned about.
Regularly eating fish has been associated with:
- Supporting healthy blood pressure
- Supporting healthy cholesterol levels
- A potentially lower risk of irregular heart rhythms
- Reduced risk factors for stroke and heart attack
These effects tend to be more pronounced when combined with a diet genuinely high in plant-based foods rather than fish alone.
There's also some association between this style of eating and better blood sugar management, which may be relevant for those managing or at risk of type 2 diabetes – often alongside related concerns like high blood pressure or weight management. A pescatarian diet, combined with plenty of plant-based food, may support these areas, though it isn't a treatment or cure for any diagnosed condition. Plant compounds more generally are associated with anti-inflammatory properties that may support broader metabolic health.
What Are the Best Fish to Eat on a Pescatarian Diet?
Oily fish is generally the priority, whether fresh, canned or frozen – all are nutritionally valuable, and fresh isn't always practical or accessible.
Fresh: salmon, trout, tuna, pollock, mackerel, sardines, herring
Canned: tuna, salmon, mackerel, sardines
Frozen: any of the above
Seafood: prawns, shrimp, scallops, clams
Non-oily fish varieties are also worth including for variety, alongside oily fish rather than instead of it. It's worth avoiding fish coated in breadcrumbs or batter where possible, since there are plenty of simple, healthier cooking methods available.
Pairing fish with a good variety of vegetables – particularly leafy greens – along with small portions of grains or legumes, herbs and citrus, makes for a genuinely balanced plate. Cooking "en papillote" (wrapped loosely in foil or greaseproof paper) is a simple way to keep fish moist and flavourful.
Is Mercury in Fish a Concern?
Mercury is a genuine consideration, but not a reason to avoid fish altogether. Longer-living fish tend to accumulate higher mercury levels over time, since larger fish that live longer typically eat smaller fish throughout their lives.
Salmon, cod, shrimp and sardines are generally lower in mercury, while species like swordfish, king mackerel and shark tend to contain higher levels. This varies by catch location and water composition too.
A varied, balanced pescatarian diet shouldn't create meaningful mercury exposure for most people, though it's worth being particularly mindful during pregnancy, when official guidance recommends limiting or avoiding higher-mercury fish specifically.
Sustainability Considerations
Depleted fish stocks in various parts of the world are an ongoing concern, and fish farming, while addressing some of that pressure, brings its own set of environmental questions – including impact on local ecosystems and the risk of introducing non-native species that could affect existing fish populations.
Overfishing remains a genuine issue globally, though some countries are actively working to address it through more sustainable fishing practices. It's a complex, evolving area without a single simple solution, but choosing sustainably sourced fish where possible is a reasonable way to make more responsible choices as a pescatarian.