TOKYO — Protein is one of the important nutrients for building muscle and we often hear that it’s better to eat a lot of it, but when is the best time to eat it? Japanese experts recommend eating a lot of protein at breakfast to build muscle effectively.
Shibata Shigenobu, a professor at Aiko Gakuen Junior College who specializes in chrononutrition, said, “Initially, we thought it would be best to consume an equal amount at each meal.”
Shibata said US studies had previously found that consuming protein evenly across three meals – breakfast, lunch and dinner – while keeping total daily protein intake constant resulted in higher rates of muscle protein synthesis than consuming a very large amount at dinner.
Shibata and his team next looked at what happens when you consume more protein in the morning. In an experiment in which mice were fed twice a day, they compared three cases: more protein in the morning, the same amount of nutrients in the morning and evening, and more protein in the evening. As a result, they found that mice that consumed more protein in the morning had a higher rate of muscle mass gain than mice that consumed more protein in the evening or mice that consumed the same amount of protein in the morning and evening.
This means that if your daily protein intake remains constant, consuming more protein in the morning will be more effective at building muscle mass.
When researchers looked at the correlation between protein intake at each meal and muscle mass in older adults, they found that those who consumed sufficient protein in the morning had more muscle mass than those who consumed protein at lunch or dinner.
“Add one more item to breakfast”
Why is it effective to take in protein in the morning? When muscles are subjected to a certain amount of stress, muscle fibers become thicker and muscle mass increases, but most people are active during the day. “Muscles are built by taking in the protein that is the building block of muscle in the morning,” Shibata explains.
Shibata said that in order to prevent muscle loss due to aging, it is recommended that a person consume a total of 1.2 grams of protein per kilogram of body weight each day (for example, 60 grams for a person weighing 50 kilograms), with 30 to 40 percent of that being consumed at breakfast. “It’s a good idea to add another item to your breakfast, such as yogurt, natto, or boiled eggs,” he advised.
Meanwhile, cells have a mechanism called “autophagy” that breaks down old proteins and creates amino acids to make new proteins. According to Shibata, autophagy is active at night when muscles are not being used, especially during sleep. Elderly people who eat too much may lose muscle mass due to autophagy, and consuming dairy products before going to bed is effective in preventing muscle loss.
(Miyuki Fujisawa, Lifestyle, Science and Environment Reporter)
