For the most part, managing one's health is a matter of eating well, sleeping well, and having regular bowel movements.
この場合、次のような言い方ができますよ。
ーFor the most part, managing one's health is a matter of eating well, sleeping well, and having regular bowel movements.
「健康管理はきちんと食べ、寝、出すことが基本です」
ここでの「出す」は to have regular bowel movements「規則的な便通がある」を使って言うと良いと思います。
ご参考まで!