Protein Day (Tanpakushitsu no Hi)

What Is Protein Day?

September 11 is "Protein Day." Of the amino acids that make up protein, 9 are "essential amino acids" that the body cannot produce on its own, while 11 are "non-essential amino acids" that the body can make itself. This anniversary was established by combining the numbers "9" and "11" to represent these two groups.

The Origins and Background of Protein Day

Protein is the nutrient that forms the building blocks of muscles, organs, skin, hormones, and other tissues throughout the body. It's made up of 20 different amino acids, 9 of which the body cannot synthesize on its own and must obtain through diet — these are known as "essential amino acids." This anniversary was registered with the Japan Anniversary Association in 2021.

• Origin: 9 essential amino acids + 11 non-essential amino acids = 20 amino acids total
• Year registered: 2021
• Purpose: To promote understanding of the importance of protein

Trivia About Protein

• The 9 essential amino acids: Valine, leucine, isoleucine, threonine, methionine, lysine, phenylalanine, tryptophan, and histidine.
• Foods rich in protein: Meat, fish, eggs, soy products, and dairy are all major sources.
• Risks of deficiency: Not getting enough protein can lead to muscle loss and a weakened immune system.

Tips for Enjoying Protein Day

Take this day as a chance to reflect on whether your meals include a good balance of meat, fish, soy products, and dairy. Planning meals with protein in mind is a great first step toward better health.