To boil down the nutrition facts on sushi—and whether or not it should be our go-to healthy date night dinner dish—we spoke with Rebekah Blakely, RDN, nutrition expert for The Vitamin Shoppe. Unsurprisingly, the answer isn’t quite black and white.

Is Sushi Healthy?

In short: Sushi can be good for you in moderation. Studies have shown that those who adhere to Japanese food guidelines have a 15% lower mortality rate. “This would include eating foods like sushi, fish, pickled vegetables, miso, and seaweed,” explains Blakely. Many studies also point to the benefits of regularly consuming fish and getting adequate omega-3 fatty acids (including decreased risk of heart disease, stroke, autoimmune issues, and depression). As the research demonstrates, sushi ingredients can offer many health benefits, from iodine in seaweed (it improves thyroid health) to the vitamin A content in fish (for glowing skin and a stronger immune system). “Just keep in mind that eating high-calorie sushi rolls a couple times per week with no other changes will not produce the same results [as the studies].”

What Makes Sushi Unhealthy

While fresh fish is a great protein source and can supply healthy fats the body needs, many of the things we eat in conjunction with sushi can really add up in terms of calories and sodium with little nutritional value. “A lot of people think of sushi as one of the healthiest options when eating out—and it can be,” says Blakely. “However, not all sushi is good for you. It depends a lot on the ingredients used and how it’s prepared.” For example, the most common sushi item is a sushi roll. Sushi rolls are usually seafood and vegetables wrapped in white rice. The rice is mixed with vinegar and sugar and packed tight. “Just one sushi roll can contain a half cup to 1 cup of rice and usually 300 to 500 calories (for most specialty rolls), and a lot of people order two or three rolls,” says Blakely. There’s a connection between a high intake of refined carbs—like white rice—and increases in blood sugar and insulin, which can in turn increase the risk of diabetes and heart disease. When you add mayonnaise-based sauces, fried sides, and/or sake, you’ve likely come close to your calorie needs for the day. If you dip your rolls in soy sauce, you might save on calories, but just one tablespoon has almost 900 milligrams of sodium (almost 40% of the daily recommendation), not to mention the extra sodium in the sushi itself. Oof.

Mercury Content

Another concern for those eating sushi regularly is mercury content. Some fish—including king mackerel, marlin, orange roughy, shark, swordfish, tilefish, ahi tuna, and bigeye tuna—are a lot higher in mercury than others. “High exposure to mercury can lead to health issues including fatigue, depression, weight loss, memory loss, and more serious neurodegenerative issues,” Blakely says. There are multiple studies that explore the detrimental effects of mercury toxicity. Tuna is the most common source of mercury exposure in the country, so keep that in mind as you place your sushi order.

How to Choose Healthy Sushi