Orange roughy and tilapia are both white fish, although very important differences exist. While orange roughy is a salt-water fish, tilapia is found in fresh water. The vast majority of tilapia is farmed -- most of the tilapia sold in the U.S. comes from China or Central America; orange roughy is primarily fished in deep waters. Both offer a range of nutritional value.
A 6-ounce portion of orange roughy contains fewer calories than the same size serving of tilapia. Orange roughy contains 178 calories versus the 223 calories in a portion of tilapia. This is relatively low, making either fish a good option for your eating plan when you are trying to lose weight. The Diet Channel recommends developing your meals to include 300 to 600 calories, depending on your gender and daily calorie requirements, so be sure to serve either a portion of orange roughy or tilapia with a vegetable and grain to consume enough calories.
Orange roughy contains fewer fats than tilapia -- 1.53 grams compared to 4.61 grams -- although both are low in saturated fat, the "bad" type of fat. Orange roughy has 0.058 grams of saturated fat per serving, while tilapia has 1.636 grams. Your body uses fat to keep your skin healthy, manufacture hormones and protect your organs, although eating too much fat increases your risk of obesity and related medical conditions.
Both fish contain good fats in the form of omega-3 fatty acids, although tilapia, as the fattier fish, is the clear winner. A 6-ounce serving of tilapia contains 480 milligrams of omega-3 fatty acids, compared to 46 milligrams in a serving of orange roughy. The American Heart Association recommends consuming two servings of fish each week -- they suggest ingesting fish with more fat to get the maximum amount of omega-3 -- to reap its heart healthy benefits. This essential fat lower your risk of developing irregular heartbeats, and it may also help control your blood pressure.
Orange roughy and tilapia serve as a rich source of protein, although tilapia provides slightly more; tilapia has 45.5 grams per serving and orange roughy has 38.9 grams per serving. The protein in these varieties of fish is considered complete, meaning that they contain all nine essential amino acids. Research in the May 2010 issue of the "American Journal of Gastroenterology" indicates that eating too much protein from animal sources, such as both tilapia and orange roughy, may increase your risk of developing irritable bowel syndrome if you are a woman, so be sure to limit your consumption of these fish and other meat proteins when appropriate.
Vitamins and Minerals
Including orange roughy and tilapia in your diet boosts your selenium intake -- a 6-ounce serving of tilapia and orange roughy provides more than 100 percent of the recommended intake. The selenium in your diet is critical to the production of antioxidants, compounds that protect your organs and tissues from free radical damage. Both fish also serve up a significant helping of vitamin B-12. Tilapia contains over 100 percent and orange roughy has 30 percent of the daily recommended value. This vitamin promotes the health of your red blood cells and nerve cells, and you need it to manufacture DNA. Your body has the capability to store vitamin B-12, so building up your stores is important
Both tilapia and orange roughy raise concerns for different reasons. The Monterey Bay Aquarium recommends seeking out tilapia farmed in the US or Central America -- tilapia farmed in Chinese waters due to pollution issues. Orange roughy contains high levels of mercury, earning an "Eco Worst Choice" rating from the Environmental Defense Fund. This fish is routinely caught via bottom trawling, according to the Monterey Bay Aquarium, which can damage habitats on the floor of the ocean.