Top sirloin steak can certainly be lean and low in calories, but if you’re one who prefers a lot of marbling -- or ribbons of fat -- in your steak, you’ll get way more fat and calories than you may realize. Whether you trim your steak or not though, you’ll add protein and several vitamins and minerals to your diet by eating it.
If you have a broiled top sirloin steak with all the fat trimmed away, a 3-ounce cut provides approximately 155 calories. A steak with some fat marbling gives you closer to 180 calories from the same portion. A broiled top sirloin that has roughly one-eighth of an inch of fat around the sides can have nearly 210 calories.
Generally the more marbling you see in your steak, the less protein you’ll get, since fat takes up a bigger chunk of the weight. For example, that 3-ounce top sirloin with one-eighth an inch of fat has about 23 grams of protein. A similar sized steak with slightly less marbling has around 25 grams, while the fully trimmed 3-ounce cooked top sirloin contains about 26 grams of protein. The Dietary Guidelines for Americans recommend a range of 50 to 175 grams of protein for a 2,000-calorie diet -- 10 to 35 percent of calories -- so a 3-ounce sirloin steak can offer as much as half of your daily protein needs.
You’ll get 5 to 12 grams of total fat from a 3-ounce broiled top sirloin steak, depending on the amount of marbling and edge fat. While some fat in your diet is essential to absorb certain vitamins and produce hormones and enzymes, not all fats are good for you. Over one-third of the total fat in any top sirloin steak is saturated, a type of fat linked to heart disease. Less than 10 percent of calories should come from saturated fat, according to the 2010 Dietary Guidelines for Americans. For a 2,000-calorie diet, this is a maximum of 22 grams of saturated fat. A fully trimmed 3-ounce top sirloin has less than 2 grams of saturated fat. But top sirloin with visible fat can have between 3 and 5 grams of saturated fat, or as much as 23 percent of your daily saturated fat allowance.
Minerals in Top Sirloin
Lean, fully-trimmed steaks have a slightly higher concentration minerals, but they all have a similar amount. One 3-ounce top sirloin provides almost 5 milligrams of zinc, a mineral that boosts your immune system, heals wounds and helps produce enzymes. That meets 44 percent of the daily zinc requirement for men and 61 percent for women. Red meat, in general, is rich in iron to improve oxygen transportation throughout your body. A 3-ounce prepared top sirloin has 9 percent of your iron recommendation for woman, or over 20 percent of the requirement for a man. That same steak has over 25 percent of your daily phosphorus needs to build up bone tissue.
B Vitamin Content
Top sirloin is one of the richest sources of B vitamins. You’ll get around 60 percent of the vitamin B-12 you need from a 3-ounce top sirloin. B-12 keeps your red blood cells healthy, protects brain cells and plays a role in sending messages around. You’ll even get small amounts of five other B vitamins -- thiamin, riboflavin, niacin, folate and B-6 -- to boost your metabolism and help your body breakdown food.