David Attenborough's diet change he credits for long life as 100th birthday plans revealed

Sir David Attenborough, the iconic voice of the Planet Earth franchise, is a national treasure with a strong history of advocacy for reducing meat consumption, embracing renewable energy, and mitigating climate change.

The natural historian is set to celebrate his milestone 100th birthday next week (8 May).

The feat is rarely achieved, with the Office for National Statistics previously suggesting that there are only 23.6 centenarians per 100,000 population in the UK.

Despite not being a staunch vegetarian or vegan, Attenborough, 99, admitted in the past that he largely eats a plant-based diet.

However, he has previously confessed that he sometimes dabbles in consuming dairy products such as cheese, as well as fish.

“But by and large, I've become much more vegetarian over the past few years than I thought I would ever be,” the father-of-two said in a 2017 interview with The Sun.

Sir David Attenborough is not a vegetarian, but often pulls back from eating red meat (BBC/Sam Baker)

Because of his penchant for the veggie diet, the Blue Planet narrator very rarely indulges in red meat, such as beef, lamb, venison, and pork.

While considered a good source of protein, red meat can increase your risk of bowel cancer, and is often high in salt, meaning regular consumption could cause your blood pressure to skyrocket, as per the NHS.

It’s advised that you eat no more than 70g of red meat per day, if at all.

Alongside cutting back on the animal-derived product, Attenborough is known to eat small portions of food.

“I’ve never really been one for eating enormous meals, and I’m not particularly a gourmet either, so I can’t pretend that I’m feeling deprived in any way or that it’s cost me all that much,” he told the Radio Times.

The animal expert tends to eat small portions (BBC)

According to experts at CNN, consuming very large food portions regularly, beyond your individual calorie needs, can lead to obesity.

People who live in Blue Zones - pockets of the world where denizens often reach 100 years and above - practice something similar.

Residents of Okinawa are known to eat until their stomach is around 80 percent full.

This ancient Japanese concept, known as ‘Hara Hachi Bu’, helps people to avoid over-indulgence and the health issues that come with it.

Plans for Sir David Attenborough’s 100th birthday

On May 8, BBC One and BBC iPlayer will air a special concert that was held in the conservationist’s honour at the Royal Albert Hall.

The star-studded centenary celebration will feature performances from Sigur Rós, the BBC Concert Orchestra, and Bastille, according to Euronews.

A 100th birthday special is set to air on BBC One and BBC iPlayer (Rob Newell - CameraSport via Getty Images)

Deadly 60’s Steve Backshall and Chris Packham - who trialled feeding his dogs vegan food earlier this year - are also set to reflect on the star’s impact on the world.

Outside of the concert, which will be hosted by Kirsty Young, a butterfly farm in Stratford-upon-Avon will be releasing 100 blue morpho butterflies in the broadcaster’s honour.

Two more shows, Making Life on Earth: Attenborough’s Greatest Adventure and Secret Garden, are also set to mark Attenborough’s milestone moment.