Jennifer Aniston owes her vitality and youthfulness to a far more disciplined approach. Picture: AP

London - Many celebrities maintain their looks with expensive skin treatments and even surgery.

But Jennifer Aniston and Reese Witherspoon owe their vitality and youthfulness to a far more disciplined approach – including not eating breakfast.

Looking almost like they did at the start of their careers more than 20 years ago, the Hollywood stars have now revealed their secrets.

Aniston, 50, sticks to regular 16-hour fasts, green juices and gruelling workouts five days a week, while mother-of-three Miss Witherspoon, 43, manages an even more heroic six weekly gym sessions and a healthy-eating regime.

Happily,  Aniston allows herself a "cheat day" once a week when she can eat what she likes.

Asked about how they start their days, they told Radio Times they’d never heard of a fry-up and never even eat breakfast.

"I do intermittent fasting, so no food in the morning," former "Friends" star Aniston said. "I noticed a big difference in going without solid food for 16 hours."

Witherspoon added: "I just have a green juice and a coffee in the morning.

"Jen knows so much about health and fitness that I always defer to her. She’s great at wellbeing advice."

To help her "thrive", Aniston doesn’t wake until 9am, while Witherspoon – who found fame in the 1999 film Legally Blonde – has it harder, rising at 5.30am with her son Tennessee, seven.

She then has a workout at 7.30am, adding: "I probably do that six days a week."

Aniston said she aims for five workouts every week, and even when she’s not fasting starts the day with a celery juice, followed by meditation and a workout.

However, her so-called 16:8 diet may not be for everyone, according to dietician Susie Burrell, who said it was "easier said than done". The 16:8 diet advocates fasting for 16 hours and eating freely for the remaining eight hours, typically between 10am and 6pm.

In addition to weight loss, intermittent fasting is believed to improve blood sugar control, boost brain function and increase life expectancy. But Burrell said: "Rather than dinner at 8pm and not eating until 12pm the next day, you will get the best results if you eat dinner by 5pm to 6pm and not eat until 9am or 10am so you still reap the metabolic benefits of consuming calories in the first half of the day."

Aniston and Witherspoon are starring in the new TV drama The Morning Show, which will be screened on Apple TV+ next month. The series, for which they are also co-producers, is about rivalry and sexual harassment on a TV news programme.

They are keen to highlight how things have changed for actresses since the MeToo movement took off. But despite starting on Friends when she was just 25, Aniston said she had not been a victim herself, adding: "I have had a pretty easy time."

Witherspoon said: "We are entering a time where female voices are important in Hollywood, because women see things in a different way.

"Jen and I probably wouldn’t have been able to make this show ten years ago. But people are taking us more seriously as creators and producers."

Daily Mail