Protein Bioavailability: Protein Source and Body Absorption

When it comes to protein, it’s not just how much but also when (anabolic window) and what sources lead to optimal digestibility, absorption, and protein bioavailability. 

So, when we eat steak, how much protein do we actually use, and are we utilizing all amino acids?

This comprehensive guide summarizes and explains new research and answers common questions. 

What is the bioavailability of protein?

Protein bioavailability determines how efficiently your body can absorb and utilize the protein you consume. It’s not solely about the quantity of protein you eat but also its quality. In simpler terms, it’s about making sure your body gets the most out of every gram of protein you ingest

Protein rating scale/ The PDCAAS rates

To rate proteins The National Library of Medicine suggests measuring:

• protein efficiency ratio 
• biological value 
• net protein utilization 
• protein digestibility 
• corrected amino acid score 

Animal Protein Bioavailability

Proteins have higher scores for protein bioavailability.
Proteins from animal sources like eggs, milk, meat, fish, and poultry are considered high-quality because they are ‘complete’ proteins. 

However, these sources also come with saturated fats and cholesterol. But at the same time meat based proteins help with lean mass and muscle recovery. 

Whey Protein Bioavailability 

Whey is one of the two main protein groups in cow’s milk, accounting for 20% of the milk, with casein making up the rest. Whey protein is rich in essential and branched-chain amino acids and has many beneficial properties.

The three types of whey protein and their bioavailability:

• whey powder 
• whey concentrate 
• whey isolate

Plant Protein Bioavailability 

When combined, vegetable proteins are a great source of protein and include all essential amino acids. 

The benefits are reduced saturated fats and cholesterol intake and added fiber. 

Common sources include: 

• legumes
• nuts
• soy 
• Textured vegetable protein (TVP) is a form of vegetable protein made from isolated soy flour, often used as a meat substitute in vegetarian products.. 

Soy is a complete protein with a high concentration of essential amino acids. 

three types/ uses of soybean: 

• flour 
• concentrates
• isolates 

What is the most bioavailable form of protein?

Animal/meat proteins are crucial for our nutrition throughout life. However, relying too much on animal-based diets can have health risks. 

You can achieve the same benefits with a mixture of plant-based proteins, but it might be harder to maintain muscle mass. Soy protein, in particular, is healthy.

For athletes, casein is best for longer-lasting protein synthesis, while whey protein works quickly for immediate results. It’s a good idea to combine the two or have smaller, more frequent servings of whey protein. 

For now, we see the best result in balanced and appropriate protein intake. 

We need more research to fully understand how different protein sources can benefit athletes in their diet.

So far, we have most data on:

Whey Protein

Whey protein, derived from milk, is often considered the gold standard for protein bioavailability. It is rich in essential amino acids and boasts a high PDCAAS score. Whey protein is rapidly absorbed by the body, making it an excellent choice for post-workout recovery.

Eggs

They contain all essential amino acids in optimal proportions. The protein in eggs is highly digestible, making them a versatile addition to your diet.

Lean Meats

Lean meats like chicken, turkey, and fish are excellent choices for protein bioavailability. They provide a significant amount of high-quality protein while being low in fat. The amino acid profiles in lean meats are conducive to efficient absorption.

How to Enhance Protein Bioavailability

Pair Proteins with Fiber

Fiber-rich foods like vegetables and whole grains can enhance protein bioavailability. They slow down digestion, allowing your body more time to absorb amino acids.

Include Healthy Fats

Incorporating healthy fats, like those found in avocados, nuts, and olive oil, can improve the bioavailability of protein. Fats help slow down protein absorption, ensuring a steady release of amino acids.

Cooking Method

The way you prepare your food can influence protein bioavailability. Cooking methods such as grilling, roasting, or steaming are better options than frying, as they help preserve the protein’s quality.