Beef, flank, steak, separable lean and fat, trimmed to 0" fat, select, raw

Beef flank steak is a long, flat cut sourced from the abdominal muscles of cattle. Known for its pronounced grain and lean profile, flank steak historically was a secondary cut compared to more tender steaks like ribeye or filet. However, its robust beefy flavor, versatility in cooking, and lower fat content have elevated its status in modern cuisine. In culinary traditions from Latin America (e.g., carne asada) to French and Asian stir‑fries, flank steak provides a satisfying protein with a distinct texture when sliced properly across the grain to break up long muscle fibers and improve tenderness. Flank steak's production has roots in traditional butchery, where this working muscle was prized for hearty, flavorful meals rather than luxury dining. Today, it’s commonly marketed as a lean steak option with broad culinary uses, including grilling, broiling, sautéing, and marinating. Although grades like "select," "choice," and "prime" reflect marbling and tenderness differences, trimming visible fat to 0"—as in this USDA FDC entry—means the steak is exceptionally lean. Compared with cuts with heavier marbling, lean flank steak delivers a concentrated amount of protein and essential nutrients per calorie with less saturated fat. Its lean nature also makes it a relative favorite among diets focused on macronutrient balance, such as paleo, ketogenic, and high‑protein plans. In gastronomy, flank steak’s grain structure demands skill: marination with acidic components like citrus or vinegar helps break down connective tissue and enhances tenderness prior to quick, high‑heat cooking. After cooking, slicing perpendicular to the grain maximizes eating quality and texture. This cut’s regional names and uses vary globally: in Mexican cuisine it’s often served as carne asada, while in Europe it can appear as London broil or thinly sliced for carpaccio in more contemporary menus. Overall, flank steak embodies a balance between affordability, nutrient density, and flavor depth, anchoring dishes from everyday grilling to elegant sliced steak salads.

At its core, lean beef flank steak is a concentrated source of high‑quality complete protein, supplying 21.22 g per 100 g raw—significantly above many common protein foods. This complete protein includes all essential amino acids vital for muscle synthesis and metabolic function. Among the amino acids reported by USDA, leucine (1.688 g) and lysine (1.793 g) are pivotal for muscle protein synthesis and recovery after exercise. Flank steak’s total fat content stands at 6.06 g per 100 g raw, with saturated fats localized mainly in palmitic (1.585 g) and stearic acids (0.724 g). While red meat contains saturated fat, flank steak is leaner than more marbled cuts like ribeye or porterhouse. Its cholesterol content of 62 mg per 100 g raw provides necessary sterols for cell membrane integrity but should be factored into dietary cholesterol limits for certain populations. Micronutrient density is a key advantage: iron (1.54 mg) in the form of heme iron is highly bioavailable, essential for hemoglobin formation and oxygen transport. Zinc (3.6 mg) supports immune function and wound healing, while selenium (24.5 µg) acts as an antioxidant cofactor in glutathione peroxidase. B‑vitamins, especially niacin (5.671 mg) and vitamin B6 (0.586 mg), facilitate energy metabolism and neurological health. Smaller quantities of other minerals like phosphorus (197 mg) and potassium (326 mg) further contribute to electrolyte balance and bone health. Compared to other protein sources, lean flank steak offers a nutrient density that supports anabolic metabolism without excessive caloric load. For instance, per calorie, flank steak delivers more complete protein and bioavailable iron than many poultry or plant sources, making it especially useful in diets addressing anemia or muscle maintenance. Fatty acid composition includes monounsaturated fats like oleic acid (2.212 g), which in moderate amounts can support heart health when balanced with polyunsaturated fats. While carbohydrates are negligible (0 g), the nutrient profile centers on protein and micronutrients, positioning flank steak as a valuable nutrient source in balanced eating patterns.

The health impact of lean red meat like flank steak spans multiple body systems—each with well‑documented physiological roles supported by clinical research. 1. Muscle Protein Synthesis and Maintenance: High‑quality protein from flank steak supplies all essential amino acids, including leucine, which stimulates muscle protein synthesis. This is critical for athletes, older adults combating sarcopenia, and individuals during recovery after injury. 2. Iron‑Status Support: Heme iron in red meat is absorbed more efficiently than non‑heme iron from plant sources. Adequate iron intake prevents iron‑deficiency anemia, particularly in populations at risk, such as women of reproductive age. Consuming flank steak alongside vitamin C‑rich foods can further enhance iron absorption. 3. Immune Function: Zinc—abundant in flank steak—is a cofactor in numerous immune pathways, including T‑cell function and wound healing. Insufficient zinc intake can impair immune responses and delay tissue repair. 4. B‑Vitamin‑Mediated Energy Metabolism: Vitamins like niacin and B6 participate in energy metabolic pathways essential for ATP production, nervous system health, and red blood cell synthesis. Flank steak delivers these B vitamins in bioavailable forms, aiding energy levels and neurological function. 5. Antioxidant Support: Selenium contributes to antioxidant enzyme systems (e.g., glutathione peroxidase), mitigating oxidative stress that can damage cellular structures. While research on red meat and chronic diseases yields mixed findings, randomized controlled trials on lean unprocessed beef suggest that moderate intake, as part of a balanced diet, does not significantly worsen cardiovascular risk markers compared to diets with other protein sources. Animal studies also support lean red meat’s role in balanced amino acid provision without excessive saturated fat intake. However, long‑term epidemiological evidence does associate high overall red meat consumption—especially processed forms—with increased risks of certain chronic diseases, underscoring moderation and dietary pattern context (e.g., plant‑forward eating with occasional lean meats).

Source: USDA FoodData Central (FDC ID: 169564)