David and Victoria Beckham
David and Victoria Beckham attend the British Fashion Awards 2015 Getty

Victoria Beckham shuns cocktails in favour of chewing coffee beans on nights out – and son Brooklyn doesn't approve.

The health fanatic, 43, has sparked a new diet trend by reportedly refusing alcohol in social situations and instead getting a caffeine fix to keep cravings at bay.

But the fashion designer's eldest son Brooklyn, 18 – who has recently moved to New York – isn't keen.

A source told The Sun: "Brooklyn really isn't a fan. In fact, he's pretty disgusted by it. Victoria will quite happily chew coffee beans if tempted to have a drink while socialising.

"She wants to remain fresh in mornings and only truly lets her hair down on significant occasions," they added.

Mrs Beckham – who is famed for her super svelte figure despite having four children – is known to exercise every single morning before work at around 6am and has a few bizarre eating habits.

One of them came to light recently when the former Spice Girl told her Instagram followers on stories that she starts her day with a dose of apple cider vinegar. She shared a snap of a Braggs' apple cider vinegar to her 17.4m followers with the advice: "Be brave! 2 tbsp first thing on an empty tummy! X"

The designer also recently revealed what snack her children eat after school – mixed seeds grilled in vegetable aminos – which freaked some of her fans out.

Beckham has often talked about her approach to staying trim in the past.

"I go for a three-mile run every morning and I work out for an hour with a personal trainer, which gives me just enough time to get to the kitchen to puree Romeo's avocados," she told Vogue Nederland in June.

She also discussed losing baby weight after the birth of Harper in 2011. She said: "I worked out a lot. I ran a lot. I did it six days a week. I become quite obsessive when I get into something."

Prior to this, she told Elle Magazine: "Normally, I wake up, do half my work-out – an hour – wake the kids up, give them breakfast, take them to school, come back, do another hour, quickly shower and then come into work.

"I eat lots of fish, lots of vegetables and a lot of fruit. I work out every day, six or seven days [a week]."

Brooklyn Beckham Victoria Beckham
Brooklyn Beckham fell in love with New York City during his numerous visits there to support his mum Victoria Beckham during the New York Fashion Week Dimitrios Kambouris/Getty Images