Is Fish Good for Weight Loss? Best Types to Eat

Why Fish Works So Well for Weight Loss

If you're looking to lose weight without feeling constantly hungry, fish deserves a regular spot on your plate. The math is simple: a 3-ounce serving of cod contains about 90 calories and 20 grams of protein. Compare that to the same amount of ground beef at 230 calories, and you can see why fish gives you more nutritional bang for fewer calories.

But the benefits go beyond just being low-calorie. Research has found that people who eat fish as their primary protein source tend to consume fewer calories overall. One study showed that participants who had fish for lunch ate 11% fewer calories at dinner compared to those who had beef. That natural appetite-suppressing effect comes from fish protein being highly satiating—it triggers fullness signals to your brain more effectively than many other protein sources.

Then there's the omega-3 factor. Fatty fish like salmon, mackerel, and sardines contain EPA and DHA—omega-3 fatty acids that reduce inflammation in the body. Chronic inflammation is linked to weight gain and metabolic dysfunction, so these healthy fats actually work in your favor rather than against your goals. Studies have shown that people who consume omega-3s regularly may see reductions in abdominal fat when combined with diet and exercise.

Fish is one of dozens of weight-loss-friendly proteins covered in our 100 Best Foods for Weight Loss guide, which breaks down exactly what to eat and why it works.

The Best Fish for Weight Loss (By Calorie Count)

Not all fish are created equal when it comes to calories, though all offer solid protein. Here's how popular varieties stack up per 3-ounce cooked serving:

Leanest options (under 100 calories): Cod comes in at around 90 calories with 20 grams of protein—one of the best ratios you'll find anywhere. Tilapia, flounder, and sole are similarly lean, all hovering between 80–100 calories per serving. These white fish are mild in flavor, cook quickly, and pair well with almost any seasoning.

Moderate options (100–150 calories): Shrimp, halibut, and haddock fall into this range. They're still very lean and offer excellent protein density. A serving of shrimp delivers about 20 grams of protein for 110 calories—plus it cooks in minutes.

Fatty fish (150–200 calories): Salmon, trout, and mackerel have more calories because they contain healthy fats. A 3-ounce portion of salmon runs about 175 calories with 19 grams of protein, but those extra calories come with omega-3s that support heart health and may actually aid fat loss. Don't skip these just because they're higher in calories—the nutritional payoff is worth it.

The key is preparation. A beautifully lean cod fillet becomes a calorie bomb when it's battered and deep-fried. Stick to baking, grilling, broiling, or air-frying to keep the calorie count where you want it.

How to Make Fish Part of Your Weight Loss Routine

The biggest barrier to eating more fish isn't nutrition—it's the perception that it's complicated to cook or expensive to buy. Neither has to be true.

Frozen fish is often flash-frozen right after being caught, which means it's frequently fresher than the "fresh" fish sitting in the display case at your grocery store. It's also cheaper. A bag of frozen cod or tilapia fillets costs a fraction of fresh and cooks from frozen in under 20 minutes. Keep a bag in your freezer and you've always got a protein option ready.

Canned fish—especially tuna and salmon—is another underrated option. It's shelf-stable, requires zero cooking, and works perfectly in salads, grain bowls, or mixed with Greek yogurt instead of mayo for a protein-packed tuna salad. One can of tuna in water contains about 25 grams of protein for roughly 100 calories.

For weeknight cooking, simplicity wins. Season a fillet with salt, pepper, and lemon, then bake at 400°F for 12–15 minutes. Pair it with roasted vegetables or a simple salad, and you have a complete meal in under 30 minutes. If you want to batch-cook fish for the week, our Complete Meal Prep Guide covers strategies for preparing proteins in advance without them drying out.

A Note on Mercury

You've probably heard concerns about mercury in fish. Here's the practical reality: the fish most people eat regularly—salmon, cod, tilapia, shrimp, pollock, and canned light tuna—are all lower-mercury options that are safe to eat several times per week. The fish to limit are the large predatory species like king mackerel, shark, swordfish, and tilefish. For most adults following a balanced diet, mercury shouldn't stop you from enjoying fish regularly.

The FDA recommends two to three servings of fish per week for adults, and research suggests that the health benefits of eating fish far outweigh the risks for most people.

Skip the Cooking Altogether

If cooking fish sounds like more effort than you want to invest, you're not alone. That's exactly why pre-made, portion-controlled meals exist. Our Weight Loss Meal Plan includes calorie-controlled, protein-forward meals designed to keep you in a deficit without having to think about it. Or use Build-a-Meal Plan to customize your own selections based on what you actually want to eat.

FAQs

What is the best fish for weight loss?

Cod, tilapia, and shrimp are the leanest options at around 80–110 calories per serving. Salmon is slightly higher in calories but delivers omega-3s that support metabolism and reduce inflammation. All are excellent choices for weight loss.

How often should I eat fish to lose weight?

The American Heart Association recommends at least two fish meals per week. Research suggests that eating fish five times per week may lead to greater weight loss than eating it less frequently, though any regular consumption is beneficial.

Is canned tuna good for weight loss?

Yes. Canned tuna packed in water is high in protein, budget-friendly, and requires no cooking. It's an easy way to add lean protein to salads, wraps, or grain bowls without excess calories.

Does salmon help you lose belly fat?

Studies suggest that omega-3 fatty acids from fish like salmon may help reduce abdominal fat when combined with a calorie-controlled diet and regular exercise. The protein also helps preserve muscle mass during weight loss.

Is fried fish okay for weight loss?

Frying adds significant calories from oil and breading. A baked or grilled fish fillet has roughly 100–150 calories, while the same piece fried can exceed 300 calories. For weight loss, stick to baking, grilling, or air-frying.

References

1. Seafood Health Facts. "Seafood Nutrition Overview." seafoodhealthfacts.org

2. American Heart Association. "Fish and Omega-3 Fatty Acids." heart.org

3. U.S. Food & Drug Administration. "Advice About Eating Fish." fda.gov

4. Thorsdottir I, et al. "Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content." International Journal of Obesity. 2007.

5. USDA FoodData Central. Nutrition data for fish and seafood. fdc.nal.usda.gov