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Oyster

Seafood

Oyster

Oysters are nutrient-dense bivalve mollusks exceptionally high in zinc and vitamin B12, often consumed raw or cooked as a low-calorie protein source.

Oysters are saltwater bivalve mollusks consumed as a delicacy around the world. They are prized for their unique briny flavor and smooth texture, often eaten raw on the half shell, steamed, grilled, or fried.

zinc-rich bivalve seafood

Typical serving · 100g

Common varieties · eastern, pacific, kumamoto, olympia, belon

85health

Overall context score across nutrition, safety, and diet fit

At a glance

Quick facts

Simple indicators based on nutrition, processing, and diet fit.

Low calorieHigh proteinLow carbLow glycemicWeight lossDiabetes-friendlyGut health

The story

What makes it unique

Oysters are a fast-digesting, high-protein food with negligible carbohydrates. They provide exceptional micronutrient density, particularly zinc and vitamin B12, which support enzymatic functions and energy metabolism. Their low energy density and high protein content promote satiety. As a minimally processed whole food, they retain their native nutrient profile, though their filter-feeding nature requires careful sourcing to avoid environmental contaminants.

Varieties: eastern · pacific · kumamoto · olympia · belon

#oysters#seafood#zincfoods#lowcalorieprotein#bivalve#rawbar#vitaminb12#ketoseafood#shellfish#lowcarbprotein

Per 100g

Nutrition breakdown

Macro balance and key metrics at a glance.

Energy

81kcal

Density 0.81 kcal/g

Protein

9.5g

Carbs

4.9g

Fat

2.3g

Fiber

0g

Sugar

0 g

Sodium

90 mg

Potassium

168 mg

Glycemic index

0

Glycemic load

0

Water content

83%

Standout compounds

Nutrient highlights

  • Zinc

    high

    Supports immune function, testosterone production, and wound healing

  • Vitamin B12

    high

    Essential for nerve function, DNA synthesis, and red blood cell formation

  • Selenium

    high

    Acts as an antioxidant and supports thyroid function

  • Iron

    moderate

    Crucial for oxygen transport in the blood

  • Omega-3 Fatty Acids

    moderate

    Supports heart health and reduces inflammation

Wellness map

Health scores & processing

Weight loss
85
Satiety
75
Blood sugar
95
Gut health
75
Heart health
80
Fitness
85
Processing
95

NOVA processing scale

1
Min
2
3
4
Ultra

minimally processed · Whole food

Fresh or frozen oysters are whole, unmodified animal foods. Canned or smoked versions may contain added salt or oils but remain largely unprocessed.

Diet compatibility

  • Weight loss
  • Muscle gain
  • Diabetes
  • Gut health
  • Low carb
  • High protein
  • Heart health

Relative standing

Food rankings

Qualitative ranks compared to similar whole foods.

  • Satietygood
  • Blood sugarexcellent
  • Nutrient densityexcellent
  • Fitness fuelexcellent
  • Processing qualityexcellent

Eat with confidence

Food safety profile

Raw oysters pose a significant risk of Vibrio and Norovirus infection, especially for immunocompromised individuals. They can also accumulate heavy metals like cadmium and lead from coastal waters. Cooking destroys most bacterial threats but does not eliminate heavy metals or biotoxins.

70safety

Evidence confidence 90%

  • Pesticideslow
  • Antibioticslow
  • Heavy metalsmoderate
  • Contaminationhigh

Watch for

  • Vibrio vulnificus
  • Norovirus
  • heavy metals
  • biotoxins

Safer choices

Commercially farmed oysters from monitored waters; fully cooked oysters eliminate most bacterial and viral risks.

Prep tips

Ensure oysters are sourced from approved waters. Scrub shells thoroughly before shucking. Avoid raw consumption if you have liver disease, diabetes, or a weakened immune system.

Filter-feeding behavior concentrates ocean pathogens and toxins; strict harvesting regulations and water quality monitoring are enforced in commercial operations.

Deep dive

Health analysis

How this food may fit different goals and preparation choices.

  1. Weight loss

    Low energy density and high protein content promote satiety without excess calories, making them an excellent choice for weight management.

  2. Blood sugar

    Negligible carbohydrate content results in virtually no glycemic impact, making them highly suitable for blood sugar control.

  3. Fitness & energy

    High zinc and B12 support energy metabolism and muscle recovery, though their lack of carbohydrates means they must be paired with carbs for glycogen replenishment.

  4. Gut health

    Zinc supports intestinal lining integrity and immune function, but the complete absence of dietary fiber means they do not directly feed beneficial gut bacteria.

  5. Processing quality

    Typically consumed as a whole, unprocessed food, preserving the natural matrix of vitamins and minerals.

  6. Food safety

    Filter-feeding nature means they accumulate bacteria and toxins from their water; raw consumption carries a well-documented Vibrio risk.

  7. Common mistakes

    Eating raw oysters from unmonitored waters or assuming they are safe for immunocompromised individuals; deep-frying them negates their low-calorie benefit.

  8. Best preparation

    Raw on the half shell for maximum nutrient retention, or steamed and grilled to eliminate bacterial risks while maintaining low calorie content.

Practical guide

Best use cases

When and how this food fits real eating patterns.

  • zinc supplementation

    Provides the highest natural food source of zinc for immune support and hormonal health.

  • low-carb seafood dinner

    Fits perfectly into ketogenic and low-carb diets due to negligible carbohydrate content.

  • raw bar appetizer

    A low-calorie, high-flavor starter that promotes satiety without ruining appetite for the main course.

  • post-workout mineral recovery

    Delivers high-quality protein and essential minerals like zinc and B12 to support muscle repair and energy metabolism.

Balance sheet

Pros & cons

Upsides

  • Exceptional zinc and vitamin B12 content
  • Very low in calories and carbohydrates
  • Rich in selenium and omega-3 fatty acids
  • High-quality complete protein source
  • Minimally processed whole food

Trade-offs

  • High risk of bacterial contamination when consumed raw
  • Filter-feeding nature accumulates heavy metals and biotoxins
  • Relatively high in dietary cholesterol
  • Expensive compared to other protein sources
  • Not suitable for people with shellfish allergies

Fit check

Who is it for?

Great match

  • zinc deficiency supplementation
  • low-carb and keto diets
  • weight loss diets
  • immune system support

Consider alternatives

  • immunocompromised individuals (if raw)
  • people with shellfish allergies
  • strict low-cholesterol diets

Side by side

How it compares

Open the full head-to-head analysis for nutrition, safety, and practical tradeoffs.

  • Oyster

    This food

    Oyster

    VS90% alike
    Mussels

    Compare with

    Mussels

    Oysters are lower in calories and higher in zinc, while mussels offer slightly more protein and omega-3 fats.

    Oysters are lower in calories and higher in zinc, while mussels offer slightly more protein and omega-3 fats.

    Oyster vs Mussels
  • Oyster

    This food

    Oyster

    VS85% alike
    Clams

    Compare with

    Clams

    Oysters provide far more zinc, but clams are a superior source of iron and vitamin B12.

    Oysters provide far more zinc, but clams are a superior source of iron and vitamin B12.

    Oyster vs Clams
  • Oyster

    This food

    Oyster

    VS80% alike
    Scallops

    Compare with

    Scallops

    Scallops offer more protein and fewer calories, making them better for weight loss, while oysters win on zinc and micronutrients.

    Scallops offer more protein and fewer calories, making them better for weight loss, while oysters win on zinc and micronutrients.

    Oyster vs Scallops
  • Oyster

    This food

    Oyster

    VS75% alike
    Shrimp

    Compare with

    Shrimp

    Shrimp provides more protein per calorie, but oysters deliver significantly more zinc and vitamin B12.

    Shrimp provides more protein per calorie, but oysters deliver significantly more zinc and vitamin B12.

    Oyster vs Shrimp
  • Oyster

    This food

    Oyster

    VS70% alike
    Crab

    Compare with

    Crab

    Crab meat is higher in protein and lower in calories, whereas oysters are a denser source of zinc and omega-3s.

    Crab meat is higher in protein and lower in calories, whereas oysters are a denser source of zinc and omega-3s.

    Oyster vs Crab
  • Oyster

    This food

    Oyster

    VS65% alike
    Lobster

    Compare with

    Lobster

    Lobster is a leaner, higher-protein choice, while oysters provide more diverse micronutrients like zinc and selenium.

    Lobster is a leaner, higher-protein choice, while oysters provide more diverse micronutrients like zinc and selenium.

    Oyster vs Lobster
  • Oyster

    This food

    Oyster

    VS50% alike
    Salmon

    Compare with

    Salmon

    Salmon provides abundant omega-3s and protein for fitness, but oysters are far lower in calories and richer in zinc.

    Salmon provides abundant omega-3s and protein for fitness, but oysters are far lower in calories and richer in zinc.

    Oyster vs Salmon
  • Oyster

    This food

    Oyster

    VS55% alike
    Sardines

    Compare with

    Sardines

    Sardines offer more protein and calcium, while oysters are lower in calories and uniquely high in zinc.

    Sardines offer more protein and calcium, while oysters are lower in calories and uniquely high in zinc.

    Oyster vs Sardines
  • Oyster

    This food

    Oyster

    VS70% alike
    Squid

    Compare with

    Squid

    Squid is lower in calories and higher in protein, but oysters provide vastly more zinc and vitamin B12.

    Squid is lower in calories and higher in protein, but oysters provide vastly more zinc and vitamin B12.

    Oyster vs Squid
  • Oyster

    This food

    Oyster

    VS45% alike
    Tuna

    Compare with

    Tuna

    Tuna is a superior source of lean protein for muscle gain, while oysters are a micronutrient powerhouse focused on zinc.

    Tuna is a superior source of lean protein for muscle gain, while oysters are a micronutrient powerhouse focused on zinc.

    Oyster vs Tuna

Common questions

FAQ

Answers aligned with how people search for this food.

  • Are oysters good for weight loss?

    Yes, oysters are excellent for weight loss. They are very low in calories and carbohydrates while providing high-quality protein that promotes fullness.

  • Can diabetics eat oysters?

    Yes, oysters are highly suitable for diabetics. They contain almost zero carbohydrates, meaning they will not spike blood sugar levels.

  • How much zinc is in an oyster?

    Oysters are the richest food source of zinc. A 100-gram serving of eastern oysters provides over 600% of the daily recommended value.

  • Are raw oysters safe to eat?

    Raw oysters can carry Vibrio bacteria and Norovirus. They are safe for healthy individuals if sourced from regulated waters, but immunocompromised people should avoid them entirely.

  • Do oysters have a lot of calories?

    No, oysters are very low in calories. A 100-gram serving contains only about 81 calories, making them a low-energy-dense food.

  • Are oysters high in cholesterol?

    Oysters do contain dietary cholesterol, but they are very low in saturated fat. For most people, the dietary cholesterol in shellfish has minimal impact on blood cholesterol levels.

  • Can you eat oysters on a keto diet?

    Yes, oysters are keto-friendly. They are low in carbohydrates and high in protein and healthy fats, fitting well into a low-carb macronutrient profile.

  • What do oysters do for men's health?

    Oysters are exceptionally high in zinc, a mineral essential for testosterone production and male reproductive health. Zinc also supports immune function and wound healing.

Transparency

Data confidence

Estimated confidence for nutrition data, interpretation, safety notes, and comparisons.

95

Nutrition data

90

Health analysis

90

Food safety

85

Comparisons