Do protein shakes really stay in the body for three years? Here’s busting a myth

The protein gap today

Historically, our diets were rich in unrefined and local protein sources. With refined and fast foods, our diets are rich in carbohydrates and fats, leading to protein deficiency. A 2020 study by the Observer Research Foundation identified a concerning decline in per capita protein consumption of four per cent in urban and 11 per cent in rural India. According to the Protein Consumption in Diet of Adult Indians (PRODIGY) survey, around 91 per cent of vegetarians and 85 per cent of non-vegetarian Indians fail to consume sufficient protein daily in their diets.

Protein Quality and Bioavailability

Animal-based proteins are more concentrated in essential amino acids and have higher digestibility than plant proteins, meaning our body can extract more amino acids from them. Eggs rank highest among whole foods with a bioavailability of 100, serving as a standard for measuring other sources. On the bioavailability scale, quinoa scores 73, the highest among plant sources, followed by soy at 70 and beans, pulses, grains and millets falling below 70.

What about whey protein and its shake?

Whey protein, a byproduct of milk, scores 104 on the bioavailability index, slightly higher than eggs. Milk protein is about 80 per cent casein and 20 per cent whey, but whey is superior in concentration and digestibility. Whey is the dominant protein in human milk, which explains why it is gentle enough for infants.

When milk is refined for whey extraction, fats, lactose, casein, and water are removed, resulting in highly concentrated whey protein. This is easier to digest, meaning those who struggle with milk can still benefit from whey protein without issues. In fact, a typical whey protein shake is digested within two hours, contradicting claims that it takes years to digest whey protein.

Whey protein and digestion

If whey protein were to linger in the digestive tract for years, we would expect widespread digestive issues among regular users, especially athletes and bodybuilders who consume it daily. The reality is that whey protein does not cause constipation or digestive distress in healthy individuals. In addition to its high digestibility, whey protein has been linked to immune benefits

Given today’s nutrient-lacking diets, especially in a more urbanised environment, supplementing with high-quality protein like whey can help bridge the protein gap. It is a practical and efficient way to meet daily protein needs.

(Thakkar is a functional medicine expert)