Blog

Best Seafood for PCOS? 6 Shellfish Compared

2026-09-23

Short answer: Oysters fits PCOS best of the 6 types of seafood compared here: rated a good fit for 3 of the 4 PCOS subtypes. Per 100 g, Mussels (24 g) and Shrimp (24 g) carry the most protein, Oysters the least (11 g). Serving size, preparation and your subtype still change the picture, so each one is broken down below.

Take this with you

Peach scans any meal or barcode and tells you how it sits with PCOS — plus recipes, meal plans, workouts and full cycle & symptom tracking.

Download on theApp Store

At a glance

Frequently asked questions

What is the best seafood for PCOS?

Oysters fits PCOS best of the 6 types of seafood compared here: rated a good fit for 3 of the 4 PCOS subtypes.

Which seafood has the most protein?

Per 100 g, Mussels (24 g) and Shrimp (24 g) carry the most protein, Oysters the least (11 g).

How each seafood fits the four PCOS subtypes

Oysters

Oysters are a protein-dense, essentially carb-free shellfish — GI and GL are both n/a because they've never been glycemic-tested, and the small amount of carbohydrate they do carry is stored glycogen, not starch or sugar. They're also unusually rich in zinc and B12, which is the main reason they come up in PCOS nutrition conversations at all.

Read the full oysters guide

Shrimp

Shrimp is an ultra-lean protein with no meaningful carbohydrate content, so it carries essentially no glycemic load and pairs well with a low-GI, blood-sugar-stable eating pattern. It's a solid fit across PCOS subtypes overall, though how it's prepared — grilled or steamed versus breaded and fried in butter — matters more than the shrimp itself.

Read the full shrimp guide

Mussels

Mussels are a nutrient-rich protein source, offering iodine, zinc, selenium, and B12. Their moderate carbohydrate content is due to glycogen, not sugar. Fit varies by PCOS subtype; consider pairing and preparation.

Read the full mussels guide

Lobster

Lobster is essentially carbohydrate-free and protein-dense — 19 grams of protein and zero carbs or fiber per 100 grams cooked — so it carries no glycemic load to weigh, for any subtype. The real PCOS-relevant questions here are cholesterol, iodine, and above all what it's served with, since butter, bread, and sweet dipping sauces do the actual metabolic work.

Read the full lobster guide

Crab

Plain crab meat is essentially carbohydrate-free and protein-dense, so it carries no meaningful glycemic load for any PCOS subtype. The nutritional story lives entirely in preparation — breaded, fried, or mayo-heavy dishes and starch-bound imitation crab sticks behave nothing like whole crab meat and shift the picture.

Read the full crab guide

Squid

Grilled or steamed squid is a lean protein with essentially no carbohydrate, so it's glycemically quiet for insulin-resistant and post-pill PCOS. For inflammatory and lean PCOS, it's a solid depends: squid isn't an omega-3 powerhouse like fatty fish, and battered, deep-fried calamari behaves like a completely different food.

Read the full squid guide

Reading these numbers

Glycemic index (GI) ranks how quickly a food's carbohydrate raises blood glucose compared with pure glucose. Glycemic load (GL) multiplies that by the carbohydrate in a real serving, so it is usually the more useful number for an actual plate. Foods with little carbohydrate have no GI assigned at all. Servings differ between foods, and cooking method, portion size and what you eat alongside all change the real-world effect.

This page compares Peach's individual food guides side by side. It isn't medical advice, and a clinician or registered dietitian can help you fit these foods to your own plan.

Portion size changes glycemic load. Estimate the glycemic load of your own serving, or check any other food in the full GI and GL table.