Some seafood substitutes offer a healthy boost. Take cauliflower, for example. Although it can be soaked in crab-boil seasoning and served with cocktail sauce to mimic shrimp, you really can't go wrong if you overindulge. Cauliflower contains potassium, folic acid, fiber and vitamin C, and it's low-calorie, too [source: Stanton].
Other seafood substitutes, however, should be eaten sparingly. Soybeans, and their flavorful derivatives, are fillers often added to fish products to bolster serving sizes or act as a binder. You may encounter soy in recipes that contain seafood. Soy can be used as a seafood substitute, too, and is often a main ingredient in faux fish or shrimp concoctions.
While the U.S. Food and Drug Administration reports soy can lower cholesterol and reduce the risk of heart disease, eating a diet rich in soy could also pose a few health risks. Researchers who have studied soy-based diets in animals posit the effects could spell out trouble for humans. For example, ingesting large amounts of soy could delay development in children, cause early puberty onset in preteens or lower fertility rates in women.
What is considered a "large amount" of soy? Eating more than 25 grams (.88 ounces) of soy per day [source: Konkel]. In seafood substitute terms, that would be the equivalent of using 6 ounces (170.1 grams) of tempeh to make faux crab cakes or using about three-quarters of a cup of soy flour to whip up a substitute seafood casserole -- and eating all of it in one day [source: Soy Foods].
Perhaps the most pressing risk is in the processing of seafood substitutes. To create seafood substitutes, the food must first undergo extensive processing. For example, a package of vegetarian shrimp, squid or tuna is made primarily of soy protein, yam flour, taro powder and wheat gluten -- all of which are far from their natural, whole state [source: Litt]. The same goes for imitation crabmeat, which is made of minced fish and which also contains levels of sugar and salt that are more elevated than one would find in freshly harvested fish.
As with any category of foods, there's a give-and-take that comes with adding seafood substitutes to your diet at any time of year. During the holidays, however, we're all OK with splurging a little.