More people in Japan are turning to meals designed for athletes, spurred by a growing interest in sports ahead of the 2020 Tokyo Olympics.
Some are also moving away from placing excessive limits on carbohydrates and other nutrients.
These special meals are called asu-shoku, an abbreviation of a Japanese term that refers to meals for athletes; and supo-meshi, a term for sports food.
The menu at Kanoya Athlete Restaurant in Tokyo is supervised by the National Institute of Fitness and Sports.
Every day at noon, the restaurant bustles with office workers.
Said a 41-year-old self-employed man who visited the restaurant: "My body feels lighter after I eat here. I come several times a week."
A dietitian at Kanoya Athlete Restaurant in Chiyoda Ward, Tokyo, showing some of the nutritionally balanced meals available. The food, based on the science of sports nutrition, is good for one's physical and mental health.
The menu is based on the science of sports nutrition. The set meal comprises a bowl of soup, a bowl of rice and three side dishes.
Diners can pick side dishes from a list of 15 options, in line with health goals such as getting lots of protein or cutting back on fat.
Professor Mioko Nagashima from the National Institute of Fitness and Sports said: "It's important to know what kind of nutrition you're getting."
Food for athletes does not necessarily mean a fixed menu, ingredients or cooking method, he said.
It comprises "good, nutritionally balanced meals", he added.
Food for athletes effectively helps people get five main nutrients - carbohydrates, protein, minerals, fat and vitamins - in a balanced way.
People can customise their meals for athletic competition and training. For example, they can add more protein if they want to increase muscular strength, or extra carbohydrates to boost stamina.
Prof Nagashima said: "There are many women and older people who don't get protein, which builds muscles. I hope that learning about food for athletes leads them to reconsider their eating habits."
ON THE PLATE AT HOME
Food for athletes is also making its way onto tables at home.
More than 10,000 people have taken the course for Athlete Food Meister, a private qualification for those who wish to provide nutritional support for athletes.
The qualification attracted public attention when TV personality Mai Satoda, who is the wife of New York Yankees pitcher Masahiro Tanaka, received the certification.
Housewife Shiho Minamiya, 46, also holds the qualification.
When her daughter comes home exhausted from school after cheerleading practice, Ms Minamiya makes sure that the teenager gets carbohydrates from tubers and roots, as well as protein from soya milk soup.
Blogs and books about food for athletes are also becoming popular.
Mrs Rieko Yamase, wife of professional footballer Koji Yamase, has published more than 100 recipes online, based on her experience with her husband's diet. She also holds lectures.
She said: "When I give talks at schools, it is not just the mothers who have children involved in sports activities who are interested.
"Children not involved in such activities, and their mothers, are also interested. It reminds me that sports, food and health are all connected."
Dietitian Satoko Shiibashi said: "If you understand the mechanisms of the body and nutrition, and introduce food for athletes into your daily life, it's good not only for your body, but also for your mental health, such as improving concentration."