Is Seaweed Fattening?

Few foods are as lauded by nutritionists as seaweed. A food and medicine source that the U.S. National Ocean Service notes was used for millennia by ancient Roman and Egyptian civilizations, seaweed is now frequently touted and recommended by wellness influencers, doctors, and dieticians across social media and in healthcare settings.

Its unique nutritional benefits and medicinal properties have helped seaweed soar in popularity in recent decades, causing the global commercial seaweed market to reach more than 17 billion last year, per one analysis.

What is seaweed?

Similar to most land-based plant life that humans consume, seaweed can vary greatly in shape and size but consists of plants grown across the world’s oceans. “It’s made from sea vegetables that can be eaten and used for culinary purposes,” explains LeeAnn Weintraub, a registered dietician and nutrition consultant based in Los Angeles.

Most commercial seaweed is grown and cultivated in seaweed farms, with many varieties being ready to harvest in as little as 6 to 8 weeks. Seaweed is often large and leafy, and comes in hundreds of colorful varieties including dulse, hijiki, wakame, red algae, and kombu.

Is seaweed a healthy snack?

No matter how you enjoy it, seaweed is full of health benefits. Just 26 grams of Nori seaweed, for instance, packs 1.5 grams of protein, 92 milligrams of potassium, 18 milligrams of calcium, 15 milligrams of phosphorus, and 10 milligrams of vitamin C, per the U.S. Department of Agriculture. It also contains iron, magnesium, zinc, copper, riboflavin, vitamin B6, folate, vitamin A, vitamin E, and a single serving of seaweed offers a fifth of the recommended intake of vitamin K one needs each day.

Seaweed is also a great source of fiber to promote gut health, antioxidants to prevent or delay cell damage, and may also be helpful in reducing inflammation and one’s risk of colon cancer.

Another benefit provided by seaweed is that it can be helpful in healthy weight management. Many varieties are very low in fat, and seaweed’s high-fiber content – a 5-gram serving of brown algae has nearly 15% of one’s daily recommended amount – not only helps prevent digestive issues but can also leave one feeling fuller for longer. This can help with appetite control and satiety.

“Seaweed is also low in sugar and calories,” says Caroline Susie, a registered dietician and national spokesperson for the Academy of Nutrition and Dietetics. Indeed, 10 sheets of Nori seaweed contain just 9 calories and about a tenth of a gram of sugar.

“All this makes seaweed a good choice for those watching their weight,” says Goodson. “Additionally, seaweed’s nutrient density means you get a lot of nutritional bang for your buck – making it a valuable addition to a balanced diet.”