Over the years there has been much debate about whether fish is a friend or foe. The jury is in and the results may shock you. 

Fish in moderation has major health benefits, from boosting your heart health to improving cognitive functions in seniors. There are even links to eating fish and helping with diabetes, joint health, and dementia.

But how much fish should you be eating to reap those benefits? Let’s take a closer look at what a serving size is of fish and how many you should be eating on a weekly basis. 

What Is A Serving Size? 

The American Heart Association considers 3.5 ounces of cooked fish, or about 3/4 cup, to be a single serving. A can of tuna contains about 5 ounces and lists 2 ounces, or 1/4 cup, as an appropriate single serving size on the nutrition label.

The American Dietetic Association food exchange, as described by the National Heart, Lung, and Blood Institute, calculates using 1-ounce servings of fish. Many restaurants and home cooks serve more than one serving’s worth in a single meal. To estimate a single serving without weighing or measuring it, 3 ounces of fish is generally about the size of a woman’s palm.

So if you’re out to dinner with friends no need to bring your scale or measuring cups, simply use your palm to get a general sense of a serving of a fish filet. 

serving sizes of fish

The Right Amount of Fish 

Fish and other seafood are rich in omega-3 fats, but they also contain a high amount of other nutrients such as Vitamin D and Selenium. High amounts of protein and saturated fat are also found in a large variety of seafood so it is important to include them in a weekly meal rotation. How often should you include seafood in your day-to-day life?

Nearly all nutritionists suggest striking a balance, no matter what the type of food being eaten is. From junk food to healthy high-protein meats, it’s all about balance. 

The Harvard T.H. Chan School of Public Health suggests eating up to 12 ounces (two average meals) a week of a variety of fish and shellfish that are lower in mercury. Shrimp, canned light tuna, salmon, pollock, and catfish are low-mercury fish. Albacore (“white”) tuna has more mercury than canned light tuna. So limit your intake of albacore tuna to once a week. 

The American Heart Association recommends eating about two servings of fish per week, 6 or 7 ounces of fish, to reap the benefits of high levels of omega-3 fats. Most people should try to keep fish consumption under 12 ounces per week, or about three to four servings, to avoid mercury contamination.

Above you will find a chart that is a quick reference for the amount of fish in a serving and which species have more mercury than others.