Flank steak is one of the leaner cuts of beef you can buy. It comes from the abdominal muscles of the cow, an area that gets plenty of exercise and doesn’t accumulate much intramuscular fat. By USDA standards, a cut qualifies as “lean” if it contains less than 10 grams of total fat, 4.5 grams or less of saturated fat, and fewer than 95 milligrams of cholesterol per 3.5-ounce serving. Flank steak comfortably meets those thresholds.
How Flank Steak Compares to Other Cuts
Among beef cuts, flank steak sits near the top for leanness, alongside eye of round, top sirloin, and top round. It has noticeably less fat than popular cuts like ribeye, T-bone, or strip steak. A 75-gram cooked serving of flank steak contains about 3.6 grams of saturated fat, according to Health Canada’s nutrient database. That’s considerably more than a roasted skinless chicken breast (0.4 grams of saturated fat for the same serving size), but for red meat, it’s on the lighter end.
The reason flank steak stays lean is its location on the animal. The flank is a hardworking muscle group below the loin, and muscles that see constant use tend to be dense with protein and low in marbling. This is also why flank steak has a reputation for being tougher than fattier cuts if it’s not prepared properly.
Protein and Micronutrient Content
What makes flank steak appealing beyond its low fat content is the nutrient density packed into a relatively small serving. A cooked 3-ounce (85-gram) portion delivers a strong protein punch, typically around 23 to 25 grams, making it a favorite for people focused on muscle building or weight management.
The micronutrient profile is worth noting too. That same 3-ounce serving of choice-grade flank steak provides about 1.5 milligrams of iron, 4.1 milligrams of zinc, 25 micrograms of selenium, and 1.5 micrograms of vitamin B12. The iron in beef is the heme form, which your body absorbs far more efficiently than the non-heme iron found in plant foods. The zinc content alone covers roughly 37% of the daily value for most adults, and the B12 meets more than half. These nutrients are harder to get in sufficient quantities from poultry or plant-based proteins, which is one reason lean beef still holds a place in many dietary guidelines.
Where It Fits in a Healthy Diet
The American Heart Association’s 2026 dietary guidance statement specifically recommends that if you choose to eat red meat, you should pick lean cuts, skip processed forms like sausage and deli meat, and keep portion sizes moderate. Flank steak checks the first box easily. The AHA’s broader recommendation favors dietary patterns higher in plant protein and lower in animal protein for cardiovascular health, but it doesn’t call for eliminating red meat entirely. The emphasis is on frequency and portion size.
In practical terms, a 3- to 4-ounce serving of flank steak a couple of times a week fits well within most heart-healthy eating patterns. Pairing it with vegetables and whole grains rather than making it the centerpiece of a large plate aligns with the portion-size guidance.
Cooking Tips to Keep It Lean
Because flank steak is naturally low in fat, it benefits from cooking methods that don’t add much back. Grilling, broiling, and stir-frying with a small amount of oil are your best options. The cut does best with high, fast heat. Cook it to medium or medium-rare (around 130 to 145°F internal temperature) to avoid drying it out, since there isn’t much intramuscular fat to keep it moist during longer cooking.
Slicing against the grain is the single most important thing you can do for tenderness. Flank steak has long, visible muscle fibers running in one direction. Cutting thin slices perpendicular to those fibers shortens them, turning what could be a chewy piece of meat into something surprisingly tender. A sharp knife and a slight diagonal angle make a noticeable difference.
Marinating for 2 to 4 hours before cooking also helps. Acidic ingredients like citrus juice, vinegar, or yogurt break down some of the tough connective tissue on the surface while adding flavor. Since flank steak is thin and flat, marinades penetrate it more effectively than they would a thicker roast.