Clams are bivalve mollusks; various species – hard-shell (Mercenaria mercenaria – quahog by size: cherrystone, topneck, littleneck), soft-shell (Mya arenaria – steamer clams), razor clams, geoduck (giant Pacific), Manila clams, sea clams. Per 3 oz cooked (~85 g) – 125 calories, 3 g carbohydrate (from glycogen), 22 g protein, 1 g fat (less than 1 g saturated), 95 mg cholesterol, 95 mg sodium (varies). Very low glycemic impact – small amount of glycogen carb minimally affects blood sugar. Excellent for diabetes meal planning. Benefits – very high quality protein; very low fat; EXCEPTIONAL nutrient density – B12 (1000+% DV per 3 oz – highest among foods); iron (120% DV); selenium (45% DV); copper (75% DV); manganese; omega-3 fatty acids; vitamin C; rich mineral profile. Concerns – some carb (3 g; minimal but not zero like other shellfish); sodium varies by preparation (canned much higher); cholesterol moderate; shellfish allergy potential; sustainability variable. Many types with similar nutrition – hard-shell clams sized by name (Cherrystone largest, Topneck medium, Littleneck smallest, Quahog/chowder largest for chowder); soft-shell (steamer clams) – typical New England clambake; razor clams (Pacific Northwest); geoduck (giant Pacific); Manila clams (small, sweet); sea clams (commercial canned). Sustainability – generally sustainable; mostly aquacultured or well-managed wild. Canned clams convenient (check sodium – much higher than fresh). Many diabetes-friendly preparations – steamed clams with herbs, garlic, white wine (skip butter); linguine alle vongole (small pasta portion + olive oil + garlic + lots of clams); stuffed clams (small portion of stuffing); clam chowder New England (small bowl); Manhattan clam chowder (tomato-based, lower fat – better for diabetes); clams on the half shell (raw with lemon); clam pasta (small portion); clams in tomato sauce; Asian-style steamed clams with ginger; clam ceviche. Limit fried clams (clam strips, clam rolls), heavy cream preparations. Vitamin B12 – clams have among highest B12 of any food (1000+% DV per 3 oz); helps prevent deficiency common in diabetes (especially metformin users – 10-30%). Iron – clams provide 120% DV per 3 oz (heme iron, well-absorbed). For metformin users – consider adding clams regularly OR B12 supplement.
Clam Nutrition Per 3 oz Cooked
| Nutrient | Amount |
|---|---|
| Calories | 125 |
| Carbohydrate | 3 g |
| Protein | 22 g (very high) |
| Fat (total) | 1 g |
| Vitamin B12 | 1000+% DV (highest food source) |
| Iron | 120% DV |
| Selenium | 45% DV |
| Copper | 75% DV |
| Cholesterol | 95 mg |
| Sodium (fresh) | 95 mg (canned much higher) |
Clam Varieties
| Type | Notes |
|---|---|
| Littleneck | Smallest hard-shell; eaten raw or steamed |
| Topneck | Medium hard-shell |
| Cherrystone | Larger hard-shell; cooked |
| Quahog/Chowder | Largest hard-shell; tough; chowder use |
| Soft-shell/Steamer | Smaller; New England clambake |
| Manila | Small, sweet; popular for steaming |
| Razor | Long razor-shaped; Pacific NW |
| Geoduck | Giant Pacific; expensive |
| Sea/Surf | Commercial canned/chopped |
Diabetes-Friendly Applications
- Steamed clams (steamers) with garlic, herbs, white wine.
- Linguine alle vongole (small pasta portion + clams).
- Manhattan clam chowder (tomato-based; lower fat than New England).
- Clams on the half shell with lemon.
- Italian-style clams in tomato sauce.
- Asian-style steamed clams with ginger and scallion.
- Clam ceviche.
- Stuffed clams (small bread/cheese portion).
- Clams with white beans and tomato.
- Clam pasta with cauliflower (lower carb).
- Cioppino (Italian seafood stew) with clams.
- Spaghetti with clams (small pasta portion + olive oil + garlic).
- Clam dip (small portion with vegetable crudités, not crackers).
Foods to Limit
- Fried clams (clam strips – breading + oil).
- Clam roll (bun + tartar sauce + fried).
- Very large New England clam chowder bowl.
- Cream-heavy clam dishes.
- Clam dip with crackers (versus vegetables).
- Heavy butter clams.
- Stuffed clams with large bread/cheese portion.
B12 and Iron Spotlight
- Highest B12 of any food (1000+% DV per 3 oz).
- Metformin associated with 10-30% B12 deficiency.
- B12 deficiency worsens diabetic neuropathy.
- B12 deficiency causes cognitive issues.
- 1 serving weekly provides substantial B12.
- Heme iron well-absorbed (120% DV per 3 oz).
- Helps prevent iron deficiency anemia.
- Selenium, copper, manganese, zinc all rich.
- Pair with vegetables for complete meal.
- Frozen and canned options for access (watch sodium).
The Bottom Line
Clams are bivalve mollusks; various species – hard-shell (Mercenaria mercenaria – quahog by size: cherrystone, topneck, littleneck), soft-shell (Mya arenaria – steamer clams), razor clams, geoduck (giant Pacific), Manila clams, sea clams. Per 3 oz cooked – 125 calories, 3 g carbohydrate (from glycogen), 22 g protein, 1 g fat, 95 mg cholesterol, 95 mg sodium. Very low glycemic impact. Excellent for diabetes meal planning. Benefits – very high quality protein; very low fat; EXCEPTIONAL nutrient density – B12 (1000+% DV per 3 oz – highest among foods); iron (120% DV); selenium (45% DV); copper (75% DV); manganese; omega-3 fatty acids; vitamin C; rich mineral profile. Concerns – some carb (3 g); sodium varies by preparation; cholesterol moderate; shellfish allergy potential; sustainability variable. Many varieties – littleneck, topneck, cherrystone, quahog, soft-shell/steamer, Manila, razor, geoduck, sea clams. Nutrition similar across types. Many diabetes-friendly preparations – steamed clams with herbs, garlic, white wine; linguine alle vongole (small pasta portion); Manhattan clam chowder (tomato-based, better for diabetes than New England cream); clams on half shell with lemon; Italian-style with tomato; Asian-style with ginger; clam ceviche; stuffed clams (small stuffing); cioppino. Limit fried clams (strips, rolls), heavy cream preparations, large chowder portions. Vitamin B12 – clams have highest B12 of any food; helps prevent deficiency common in diabetes (especially metformin users 10-30%); B12 deficiency worsens diabetic neuropathy. Iron – 120% DV per 3 oz; heme iron well-absorbed; helps prevent anemia. For metformin users – consider adding clams 1-2x weekly OR B12 supplementation. For adults with type 2 diabetes – clams are excellent zero/low-carb very high-protein very low-fat seafood with EXCEPTIONAL nutrient density (highest B12 food, very high iron); particularly valuable for metformin users at risk of B12 deficiency; many diabetes-friendly preparations available; fresh, frozen, canned options. See our broader diabetes diet guide for context.
