What is ‘lean protein’? You might be surprised by a few of the answers

On Nutrition

Recommendations to eat “lean protein” abound, and I’m pretty sure I’ve invoked those words in a number of my columns. But what does that mean, exactly? If you think it means something like, “lean ground beef and skinless chicken breasts,” you’re partially right.

Certainly, when we think “lean” we think “low-fat.” But in reality, “lean protein” is a clumsy description for “healthy sources of protein.” That’s partly because not all dietary fat is created equal. “Lean” protein sources are relatively low in saturated fat — some have no saturated fat at all — because saturated fat contributes to high cholesterol and, in excess, can also contribute to chronic inflammation. Let’s look at your protein options.

Pulses and nuts. The leanest sources of protein are pulses — aka beans and lentils — while nuts contain protein plus fiber and healthy fats. Protein content of cooked beans or lentils averages around 6 grams per half cup of cooked beans or lentils. Soybeans are also pulses, and tofu and tempeh are versatile sources of protein. A 4-ounce serving of tofu contains about 7 grams of protein. A ¼-cup serving contains about 4 grams of protein.

Fish. Fish might be one of the more counterintuitive sources of lean protein, because “fatty fish,” or fish rich in omega-3 fatty acids, qualifies. That’s because omega-3 fats are polyunsaturated and have been shown to reduce the risk of cardiovascular disease, including heart attack and stroke. This includes salmon as well as mackerel, trout, herring, sablefish/black cod, sardines, bluefin tuna, whitefish and striped bass. Fish generally contains 17-24 grams of protein per 3.5-ounce serving.

Poultry. Skinless chicken and turkey breast meat — aka white meat — sold whole or as cutlets or fillets, are the leanest poultry choices. The darker leg and thigh meat is naturally higher in fat, but removing the skin helps a bit. Chicken breast meat has 31 grams of protein per 3.5-ounce portion, while thigh meat has 24 grams.

Dairy and eggs. Low-fat and nonfat dairy are obviously “lean,” but eggs and full-fat dairy products count, too, despite containing saturated fat. Eggs are a nutrient-rich and relatively economical source of protein — with one egg containing about 6.25 grams. As for full-fat dairy, current research shows that saturated fat from dairy does not pose the same health concerns as saturated fat from meat. One cup of milk, a 3-ounce serving of Greek yogurt or 1 ounce of hard cheese contains 7-8 grams of protein.

Beef and pork. The predominant fat is saturated. You can trim off, or simply not eat, visible fat on some cuts, but other cuts have a significant amount of marbling — flecks or streaks of fat within the lean sections of meat — which you obviously can’t trim away. Naturally leaner cuts of beef include round steaks and roasts (top round, bottom round, eye of round, round tip), top loin, top sirloin and chuck roasts. When shopping for ground beef, look for selections labeled at least 90% lean — 93% or 95% is even better. The leanest pork cuts include the loin, tenderloin, center loin and ham. A 3.5-ounce serving of beef or pork contains around 26 grams of protein.

A quick note on grams and ounces. The serving sizes I mention above are all by volume measure or scale weight. When you’re using a kitchen scale, 1 ounce = 28.35 grams. But when you’re talking about the protein content of foods, 1 ounce of protein = 7 grams of protein. This is not a weight-based measure.