How Much Protein is in 150g of Lamb Leg?

November 8, 2025 •

4 min read

The protein concentration in meat increases significantly after cooking due to water loss. Uncover the specific amount of protein in 150g of lamb leg, with detailed nutritional information and how preparation impacts its final value.

Quick Summary

This nutritional breakdown provides precise figures for the protein content in a 150g serving of lamb leg, distinguishing between raw and cooked meat and highlighting key factors affecting its nutritional density.

Key Points

Protein Content: 150g of raw lamb leg contains approximately 30 grams of protein, based on average nutritional data.
Cooked Protein Increase: After cooking, the same 150g raw portion can yield between 37.5 and 42 grams of protein in the final product due to water loss and nutrient concentration.
Lean is Best: Trimming excess fat from the lamb leg increases the protein density, maximizing the protein-to-calorie ratio.
Micronutrient Powerhouse: Lamb leg offers more than just protein; it is also an excellent source of essential minerals like iron and zinc, and vitamins such as B12.
Cooking Method Matters: High-heat cooking concentrates protein but can degrade some vitamins, while gentle methods like sous vide are optimal for nutrient preservation.
Complete Protein: As a complete protein source, lamb provides all nine essential amino acids necessary for muscle maintenance and overall body function.

The Protein Content in 150g of Lamb Leg

Determining the exact protein content in 150g of lamb leg depends on whether the meat is raw or cooked, and the amount of separable fat present. As meat cooks, its water content evaporates, concentrating the protein and other nutrients. This is a crucial factor for anyone tracking their macronutrient intake. For example, studies have shown that protein percentages increase after grilling, which is a common cooking method for lamb.

Based on data from nutritional databases, raw boneless lamb leg typically contains around 20 grams of protein per 100 grams. Therefore, a raw 150g portion would yield approximately 30 grams of protein.

Raw vs. Cooked Protein

When lamb is cooked, moisture is lost, causing the remaining nutrients to become more concentrated. For lean, cooked lamb, the protein content can increase to between 25-26% of its weight. This means that a 150g portion of raw lamb will weigh less after cooking, but its protein concentration per gram will be higher. A 150g raw portion could result in a cooked portion of around 110-120g, but contain the same or slightly more total protein. Taking average figures, a 100g serving of lean cooked lamb leg can contain 25-28 grams of protein. Scaling this up, a cooked portion equivalent to 150g raw lamb could offer approximately 37.5 to 42 grams of high-quality protein.

Factors Influencing Protein Content

Several variables can affect the final protein count in your lamb leg:

Fat Trimming: The more you trim the fat from the leg, the leaner your final meat will be, increasing the proportion of protein relative to weight. Lean, trimmed cuts will always have a higher protein-to-fat ratio.
Cooking Method: High-heat cooking methods like roasting or grilling cause more water loss, resulting in a more concentrated protein content per gram of the final product. Slow-cooking methods may retain more moisture, yielding a less concentrated protein value.
Doneness: A rare or medium-rare lamb leg will retain more moisture than a well-done one. This means that a well-done piece will have a higher protein concentration per gram due to greater water evaporation.
Source and Diet: The nutrition of the animal, including its diet (e.g., pasture-raised vs. grain-fed), can slightly affect the overall nutrient density and fat composition, which in turn influences the protein concentration.

The Nutritional Profile Beyond Protein

Lamb leg is not just a source of high-quality protein; it's also packed with other essential nutrients that contribute to overall health. It is considered a complete protein, providing all nine essential amino acids needed for muscle repair and growth.

Essential Vitamins and Minerals

Lamb is particularly rich in several key micronutrients:

Iron: Contains highly bioavailable heme-iron, which is absorbed more efficiently by the body than the non-heme iron found in plant sources. This helps prevent anemia.
Zinc: Crucial for immune function, protein synthesis, and cellular growth.
Vitamin B12: Essential for blood formation and brain function. Lamb is an excellent source of this vitamin, which is often lacking in vegan diets.
Selenium: An important antioxidant that supports thyroid function.
Niacin (Vitamin B3): Plays a vital role in energy metabolism.

Healthy Fats

While lamb contains fat, grass-fed lamb is known for having a favorable balance of omega-3 to omega-6 fatty acids and containing conjugated linoleic acid (CLA), which can be beneficial for heart health and reducing inflammation.

Cooking Methods and Nutrient Retention

Different cooking techniques can alter the final nutritional outcome of your lamb leg. Below is a comparison of common methods:


Cooking Method	Effect on Protein	Effect on Fat	Vitamin & Mineral Retention
Roasting (Lean)	Concentrates protein due to water loss, increasing density per gram.	Drips away excess fat, reducing total fat content.	Retains most heat-stable minerals like iron and zinc. Some B vitamins may be lost.
Stewing/Braising	Maintains protein content but can leach some water-soluble vitamins into the liquid.	Fat renders into the liquid, which can be skimmed off.	Excellent for preserving vitamins and minerals if the broth is consumed.
Grilling (High Heat)	Protein is highly concentrated. Risk of forming heterocyclic amines if charred.	Fat drips away from the meat.	Some B vitamins may be degraded by high heat. Minerals are largely retained.
Sous Vide	Preserves protein structure and moisture very well, resulting in tender meat.	Minimal fat is rendered.	Exceptional for retaining vitamins and minerals due to low, controlled temperature cooking.

For optimal nutrient retention and flavor, cooking lean lamb leg to medium-rare or medium, and then letting it rest, is recommended.

Conclusion

In summary, 150g of raw lamb leg provides approximately 30 grams of protein, while the same raw portion, once cooked, will likely yield between 37.5 to 42 grams of concentrated, high-quality protein. The exact amount depends on variables like fat trimming and cooking time. Beyond its rich protein content, lamb leg is a dense source of vital nutrients such as iron, zinc, and B vitamins, making it a valuable addition to a balanced diet. Whether you are aiming for muscle growth, managing iron levels, or simply seeking a nutrient-rich meal, understanding these figures helps in making informed dietary choices.

A more comprehensive breakdown of lamb's nutritional benefits can be found in this article from Healthline: Lamb 101: Nutrition Facts and Health Effects.

Frequently Asked Questions

Lamb leg is a very good source of high-quality protein, comparable to other red meats like beef. Lean cooked lamb can contain 25–26% protein, offering a significant amount per serving.

No, the protein content is not the same. When cooked, the meat loses water, which concentrates the nutrients. Therefore, cooked lamb leg has a higher protein density per gram than its raw counterpart.

Trimming the fat increases the proportion of protein per gram. A leaner cut of lamb leg will have a higher protein-to-calorie ratio, making it a more protein-dense option.

Lamb leg is a rich source of essential vitamins and minerals, including iron, zinc, selenium, phosphorus, and several B vitamins, most notably B12 and niacin.

Yes, lamb is considered a complete protein source. This means it contains all nine essential amino acids that your body needs for tissue repair and growth.

Gentler cooking methods like sous vide or braising with a lid are best for retaining nutrients, especially water-soluble vitamins. High-heat methods like grilling can degrade some vitamins, but minerals are largely retained.

To maximize protein, choose a lean cut, trim any excess fat before cooking, and use a cooking method that concentrates the protein, such as roasting. Always let the meat rest after cooking to retain juices.