While the dust settles, the best advice for the curious to take from Lifespan is to experiment with habits that are easy, free, and harmless—like taking a brisk, cold walk and eating a lighter diet. With cold exposure, Sinclair explains, moderation is the key. He believes that you can reap benefits by simply taking a walk in the winter without a jacket. He doesn’t prescribe an exact fasting regimen that works best, but he doesn’t recommend anything extreme—simply missing a meal here and there, like skipping breakfast and having a late lunch.

In his book, “Lifespan,” celebrated scientist David Sinclair lays out exactly why we age—and why he thinks we don’t have to. Read the article.