Jakarta (Indonesia Window) – Serving as Malaysia’s prime minister at the age of 94 made Dr. Mahathir Mohamad is the oldest state leader in the world.

Many people want to know the "secret" behind the health condition of Mahathir who also served as prime minister in 1981 to 2003.

"So many people ask me this question. I will write it down one day to explain to people. Not scientifically because I don't do scientific examinations," Bernama quoted Mahathir as saying.

"What I do is observing what happens to me and what happens to other people, and I draw my own conclusions," he said at a dialogue session at the 2019 ASEAN Business and Investment Summit which was moderated by the Chair of the ASEAN Business Advisory Council Arin Jira in Malaysia, Saturday (3/11).

PM Mahathir explained that he remained healthy and fit by not overeating.

"The first thing is not to overeat. Eat to live, not live to eat. That is very simple. When the food is delicious, stop eating. That is my mother's advice for me.

"When the food is delicious, stop eating. This is very difficult but we must develop discipline," he added.

Dr. Mahathir also suggested not to consume too much fat, carbohydrates and sugar in food.

In addition to staying healthy, a person must stay active and exercise regularly so as not to lose muscle.

"Active means the whole system, not just the muscles. If you use your brain all the time, you talk, think, argue, fight, it activates the brain and it will function properly.

"If it doesn't work well for certain things, do it over and over again. Whatever we do repeatedly, we will remember.

"If after retirement, we rest and sleep, the brain and body will lose its capacity," he said.

Reporting by Indonesia Window