Chicken and beef are the two protein staples of most omnivorous diets. Using USDA FoodData Central values for cooked skinless chicken breast and 90% lean ground beef, here is how they actually compare.
The answer first
Per 100 g cooked, skinless chicken breast is the leaner choice: fewer calories, more protein and roughly a third of the fat of 90% lean ground beef. Beef earns its place on minerals — it carries far more iron (heme iron, well absorbed), plus more zinc and vitamin B12. Chicken is the better pick for lean protein; beef is the better pick for those minerals.
Side-by-side nutrition (per 100 g, cooked)
| Nutrient | Chicken breast | Beef (90% lean) | Difference |
|---|---|---|---|
| Calories | 165 kcal | 176 kcal | −11 kcal |
| Protein | 31.0 g | 26.1 g | +4.9 g |
| Fat | 3.6 g | 10.0 g | −6.4 g |
| Carbohydrate | 0 g | 0 g | same |
| Iron | trace | 2.5 mg | much higher in beef |
| Potassium | 256 mg | 318 mg | higher in beef |
The “difference” column is chicken minus beef. See the same data with computed deltas on our chicken vs beef comparison page.
Protein and leanness
Chicken breast is one of the leanest protein foods available: 31 g of protein in 165 kcal works out to about 18.8 g of protein per 100 kcal, versus 14.8 g for 90% lean beef. The difference comes almost entirely from fat. Chicken breast carries just 3.6 g of fat per 100 g, while even relatively lean ground beef has 10 g. If your priority is maximum protein for minimum calories, chicken breast is the stronger option — it sits near the top of our protein per 100 calories ranking.
That said, the fat in beef is not all “bad.” It includes monounsaturated fat alongside saturated, and a fattier cut also carries more flavour and fat-soluble nutrients.
Iron, zinc and B12: beef’s advantage
This is where beef pulls ahead. Red meat is one of the best dietary sources of heme iron — the form the body absorbs most efficiently — with around 2.5 mg per 100 g in 90% lean ground beef, compared with only a trace in chicken breast. Beef is also richer in zinc and vitamin B12. For anyone managing low iron, or eating little other red meat, beef offers nutrients that chicken largely does not. (Plant eaters can reach for lentils and spinach, though that is non-heme iron, which is less readily absorbed.)
Calories and fat: it depends on the cut
The comparison above uses two relatively lean cuts. Change the cut and the picture shifts:
- Chicken thigh or skin-on chicken is fattier and higher in calories than breast, narrowing the gap with beef.
- Fattier ground beef (e.g. 70–80% lean) can exceed 250 kcal per 100 g cooked, widening the gap.
- Cooking method matters too — roasting or grilling renders out some fat, while frying adds it.
Always check whether a figure is for breast or thigh, lean or regular mince, and how it was cooked. Our how to read nutrition data guide explains why these distinctions change the numbers so much.
Which should you choose?
- Cutting calories or maximising protein: chicken breast.
- Boosting iron, zinc or B12: lean beef.
- Flavour and satiety: beef’s fat carries flavour; many find it more satisfying.
- Variety: alternating both, plus fish and plant proteins, gives the broadest nutrient coverage. Compare chicken with shrimp or tofu for more options.
There is no need to pick one forever. A diet that rotates lean poultry, lean red meat, fish and legumes covers both the protein-density and the mineral angles.
A note on accuracy
Values are USDA FoodData Central reference figures for cooked meat, per 100 g of edible portion. Cut, trimming, fat percentage and cooking method change the real numbers significantly. This article is general information, not medical or dietary advice; consult a qualified professional for personalised guidance. See our methodology for sourcing and computation.