For Jamie Oliver, finally getting some shut-eye has been the magic pill.
The celebrity chef told the Sun that after going through a rough time in the past couple of years, his mental health was far from "pukka".
"I think I'm generally known for being very optimistic, bubbly and definitely glass half full. But one day I felt sad. And for a bit too long," he told the newspaper.
The Naked Chef says it was a lack of sleep which was taking its toll, but said he found himself constantly distracted. Oliver, 43, and his wife Jools have five children, ranging from age 16 to two.
"I'd get home, see my wife Jools, cook a dinner. Then she would fall asleep because she's a mum, but I'm wired. The phone is pinging. I was going to bed at 1am consistently and getting up at 4am or 5am. It caught up with me."
While studying nutrition, Oliver began researching the power of shut-eye, and says he found that "everything comes back to sleep".
"I realised the most powerful exercise in the gym is sleep. And the most powerful part of nutrition is sleep."
Oliver says he now has a strict bedtime routine; sleeping in a cold room and blocking out any light with an eye mask, and phone out of the room.
He also makes sure he's tucked up in bed by 10pm each night.
"I'm like a baby. I have to set an alarm to go to bed. I'm 43 years old and I've got to put myself to bed."
"But I changed my habits and the difference is amazing."