Flank steak is the cut that understands you don’t always need marbling to deliver on taste. Whether you’re grilling for fajitas, slicing thin for stir-fry, or marinating for carne asada, flank steak punches above its weight. But how does it perform nutritionally? Let’s take a look.
Flank steak nutrition facts
Flank steaks are typically served in 8 oz, 12 oz, and 16 oz portions. Below are the nutrition facts for each size [*].
8 oz flank steak nutrition
- Calories: 385
- Protein: 46g
- Fat: 21g
- Carbs: 0g
12 oz flank steak nutrition
- Calories: 578
- Protein: 69g
- Fat: 32g
- Carbs: 0g
16 oz flank steak nutrition
- Calories: 770
- Protein: 92g
- Fat: 43g
- Carbs: 0g
And here’s a complete nutritional breakdown of an 8 oz flank steak:
- Calories: 385
- Protein: 46g
- Fat: 21g
- Saturated Fat: 8.1g
- Trans Fat: 0.9g
- Polyunsaturated Fat: 0.7g
- Monounsaturated Fat: 8.1g
- Carbs: 0g
- Cholesterol: 132mg
- Iron: 4.2mg (23% DV)
- Zinc: 12.6mg (115% DV)
- Phosphorus: 378mg (30% DV)
- Potassium: 752mg (16% DV)
- Sodium: 116mg (5% DV)
- Calcium: 9mg (1% DV)
- Magnesium: 43mg (10% DV)
These values represent cooked flank steak and will vary slightly based on cooking method, fat trimming, and marbling, but they provide a solid baseline.
8 health benefits of flank steak
Flank steak is one of the leaner beef cuts, which changes its nutritional profile compared to fattier steaks. Here’s what it has:
1. High protein, lower calories
An 8 oz flank steak provides 46 grams of complete protein with significantly fewer calories than fattier cuts. At 385 calories, it delivers the same protein as a ribeye but with roughly 190 fewer calories.
2. Exceptional zinc content
With 115% of your daily zinc requirement in an 8 oz serving, flank steak is one of the most zinc-dense foods available. Zinc supports immune function, wound healing, protein synthesis, and DNA formation [*]. This level of zinc is difficult to match without supplementation.
3. Bioavailable iron
Flank steak delivers heme iron, the form absorbed most efficiently by your body [*]. An 8 oz portion provides 23% of your daily iron needs, supporting hemoglobin production and oxygen transport. This translates directly to better endurance and reduced fatigue.
4. Lower saturated fat than premium cuts
An 8 oz flank steak contains 8.1 grams of saturated fat — less than half what you’d find in the same portion of fattier cuts like ribeye or filet. For those monitoring saturated fat intake for cardiovascular reasons, flank steak offers a practical middle ground between very lean cuts and heavily marbled ones.
5. B vitamin profile
Flank steak provides substantial B vitamins, particularly B12 and niacin. B12 supports red blood cell formation and nervous system health, while niacin aids in energy metabolism [*].
6. Natural Creatine
Like all beef, flank steak contains creatine naturally, approximately 0.5g per 4 oz serving. Creatine supports high-intensity exercise performance and muscle recovery [*]. Athletes and active individuals may avoid or reduce supplementation by adding more flank steak to their diet.
7. Enhanced omega-3 profile in grass-fed
When sourced from grass-fed cattle, flank steak contains higher levels of omega-3 fatty acids and conjugated linoleic acid (CLA) compared to grain-fed beef [*]. These compounds are associated with reduced inflammation and improved metabolic health.
8. Zero carbohydrates
Flank steak contains no carbohydrates, making it compatible with ketogenic, paleo, carnivore, and low-carb dietary approaches. It’s pure protein and fat.
3 potential downsides of flank steak
No cut is perfect. Here’s what to consider:
1. Contains saturated fat
While lower than fattier cuts, an 8 oz flank steak still provides 8.1g of saturated fat, which is about 41% of the daily recommended limit. Diets high in saturated fat have been associated with increased LDL cholesterol levels and cardiovascular disease risk [*]. Flank steak fits into a balanced diet, but portion sizes matter.
2. Moderate cholesterol content
An 8 oz flank steak contains 132mg of cholesterol, which is about 44% of the recommended daily limit [*]. For most people with healthy cholesterol levels, this poses no concern. For those managing existing cholesterol issues, consult your doctor.
3. Requires proper cooking technique
Flank steak is lean and comes from a well-exercised muscle. Overcook it or cut it incorrectly, and you’ll have chewy, tough meat. This isn’t a forgiving cut, but that doesn’t mean it is difficult. Cook to medium-rare or medium at most, and always slice against the grain at a sharp angle.
Where to buy healthy flank steak
Quality sourcing matters even more with lean cuts like flank steak. The healthiest options come from cattle that are 100% grass-fed and grass-finished — raised entirely on pasture without grain finishing, antibiotics, or growth hormones. This produces meat with better omega-3 ratios, higher CLA content, and cleaner overall nutrition.
At U.S. Wellness Meats, our flank steaks come from cattle raised on regenerative pastures where animal welfare and land health drive every decision. It’s beef raised the way it should be — without shortcuts.
See how good our 100% grass-fed and grass-finished flank steaks really are.
How to add flank steak to your diet
Flank steak is one of the most versatile cuts available. Here’s how to use it well:
- Classic carne asada – Marinate in lime juice, garlic, cumin, and cilantro. Grill over high heat to medium-rare, rest, and slice thin against the grain. Serve with tortillas, onions, and salsa.
- Stir-fry – Slice thin against the grain while partially frozen for clean cuts. Marinate briefly in soy sauce, ginger, and garlic. Cook fast over high heat with vegetables.
- Fajitas – Season with chili powder, cumin, and lime. Grill or sear in a screaming hot cast iron. Slice and serve with peppers, onions, and warm tortillas.
- Asian-style flank steak salad – Grill the steak to medium-rare, slice thin, and serve over mixed greens with cucumber, mint, cilantro, and a fish sauce-lime dressing.
- Stuffed and rolled – Butterfly the flank steak, stuff with spinach, roasted red peppers, and cheese, then roll and tie. Roast until medium, slice into pinwheels.
What muscle is the flank steak?
The flank steak comes from the abdominal muscles of the cow, specifically the area beneath the loin and between the rib and hip. This is part of the beef flank primal, one of the eight major sections of the carcass.
Unlike muscles from the rib or loin that do relatively little work, the flank muscles are used for breathing and core stability. This means they develop strong grain structure and less intramuscular fat. The muscle fibers run in long, visible lines across the length of the steak, which is why slicing against the grain — perpendicular to these fibers — is essential for tenderness.
The lack of marbling isn’t a flaw. It’s a direct result of the muscle’s function and location. What you lose in fat, you gain in protein density and a cleaner mineral profile. The trade-off is intentional, not accidental.
Flank steak FAQ
Here are common questions about flank steak:
Is flank steak a healthy cut?
Yes. It’s one of the leanest beef cuts available while still delivering substantial protein, iron, and zinc. An 8 oz portion provides 46g of protein with about half the saturated fat of well-marbled cuts. For anyone prioritizing protein while managing calorie or fat intake, flank steak is an excellent choice. For optimal nutrition, choose grass-fed, grass-finished flank steak.
Why is flank steak so lean?
The flank comes from the cow’s abdominal area, muscles that are constantly used for breathing and movement. Working muscles develop less intramuscular fat because they prioritize functional strength over energy storage. This is the same reason beef chuck (shoulder) and round (leg) cuts are also lean — they work hard, so they stay lean.
Is flank steak good for weight loss?
It can be. The high protein content (46g per 8oz) promotes satiety and helps preserve muscle mass during caloric restriction. With 385 calories per 8 oz serving, it’s calorically efficient compared to fattier cuts. Weight loss ultimately depends on total energy balance, but flank steak fits well into reduced-calorie diets without sacrificing protein intake.
Is flank steak healthy for cholesterol?
Flank steak contains 132mg of cholesterol per 8 oz serving, which is about 44% of the recommended daily limit [*]. It also has less saturated fat (8.1g) than fattier cuts. Grass-fed flank steak also tends toward a more favorable fat composition [*]. If you have existing cholesterol concerns, consult with a healthcare provider about appropriate portion sizes.
Why is flank steak tough?
Flank steak comes from a working muscle with strong grain structure and connective tissue. If you cook it past medium or fail to slice against the grain, it becomes noticeably tough. This isn’t poor quality — it’s the nature of the cut. Proper technique (high heat, quick cooking, correct slicing) makes all the difference.
How should you cut flank steak?
Always slice against the grain — perpendicular to the direction of the muscle fibers. Hold your knife at a 45-degree angle to create broader slices with more surface area. Cutting with the grain instead of against it leaves you chewing through long fibers, which is precisely what makes flank steak tough when handled incorrectly.
How many calories are in an 8 oz grilled flank steak?
Approximately 385 calories, with about 46g of protein and 21g of fat.
How many calories are in a 12 oz grilled flank steak?
Roughly 578 calories, with about 69g of protein and 32g of fat.
Is flank steak better than ribeye?
“Better” depends on what you’re optimizing for. Flank steak has more protein per calorie, less saturated fat, and great zinc content. Ribeye has more marbling, a richer flavor, and more forgiving cooking characteristics. If you prioritize leanness and protein efficiency, choose flank. If you prioritize tenderness and flavor richness, choose ribeye. Both are excellent cuts with different strengths.
Can you eat flank steak rare?
You can, though medium-rare is generally preferable. Flank steak has a dense grain structure, and cooking it to medium-rare (130-135°F internal temperature) allows some of the connective tissue to begin breaking down while keeping the meat juicy. Rare flank steak can be chewier than necessary. Medium-rare is the sweet spot.
The bottom line on flank steak
Flank steak is a lean, protein-dense cut that delivers substantial nutrition without the calorie load of fattier steaks. It provides 46g of protein per 8oz serving, exceptional zinc content, bioavailable iron, and B vitamins — all with half the saturated fat of premium marbled cuts.
It requires proper technique (quick cooking over high heat, precise doneness, and correct slicing), but rewards that effort with versatile, flavorful results.
For the best nutrition and flavor, choose grass-fed, grass-finished flank steak from farms practicing regenerative agriculture. At U.S. Wellness, our flank steaks come from cattle raised on open pastures with no antibiotics, hormones, or grain finishing.
Nathan Phelps
Nathan Phelps owns and writes for Crafted Copy, a boutique copywriting shop that finds the perfect words for interesting products. He is also an ethical foodie, outdoors-aficionado, and hails from Nashville, TN. He splits his time between helping sustainable businesses find new customers and managing his ever-increasing list of hobbies, which include playing guitar, baking bread, and creating board games.
