Mars bar

Both Mars and Snickers bars will retain their 51p rsps

Mars has shrunk the size of its Mars and Snickers chocolate bars by more than 10% to meet its Responsibility Deal commitments - but it’s kept the price of the bars unchanged, with an rsp of 51p, The Grocer can reveal.

The weight of a Mars bar has dropped from 58g to 51g, while Snickers has been trimmed from 58g to 48g. Mars said it had shrunk the products to meet its public health targets. The chocolate giant committed early in 2012 to cut the calorie content of its single-serve products to a maximum of 250 by the end of 2013, as part of its calorie reduction Responsibility Deal pledge.

As a result of the size changes, the number of calories in a Mars bar has dropped from 260 to 229 and in a Snickers bar from 280 to 245.

Mission for Mars: health timeline

2007: The Grocer reveals Mars has started using the animal enzyme rennet in many bestselling lines, including Mars bars. After a public backlash, it quickly returns to the original vegetarian-friendly recipes

2008: Removes all artificial colours, flavours and preservatives and cuts the size of Snickers and Mars by 7.2% to 58g

2010: Cuts saturated fat content of Mars bars by 15%

2011: Removes artificial transfats from all Mars products

2012: Signs Responsibility Deal calorie reduction pledge

2013: Reduces size of Snickers and Mars and meets Responsibility Deal target to cut calories of single-serve products below 250

Mars said it had little choice but to reduce the size of the products because there was a limit to what could now be achieved through reformulation. In 2010, it cut the saturated fat content of a Mars bar by 15% and removed all transfats.

“As part of our global commitment to promote responsible consumption, and as a signatory of the Responsibility Deal’s calorie reduction pledge, we [said we would] ensure that all of our single-serve chocolate products would contain no more than 250 calories per portion,” said a Mars spokesman.

“To meet our commitment, having taken product reformulation as far as we can for now without compromising the great taste, we have reduced the portion size of Mars and Snickers to bring down the calorie content.”

In an interview with The Grocer earlier this year, former public health minister Anna Soubry described Mars’ calorie reduction pledge as “absolutely brilliant”.

“They don’t have to do it but are doing it for all the right reasons,” Soubry said.

It is not the first time Mars has reduced the size of Mars and Snickers. In 2008, it cut the size of both products from 62.5g to 58g, while leaving the price the same.

Mars has reduced the size of the bars in the wake of big hikes in the cost of chocolate-making over the past decade.

Cost inflation was particularly severe this year. In analysis completed for The Grocer in October, commodity pricing specialists Mintec said the cost of producing an average milk chocolate bar had soared by 25% year-on-year, adding 6p to the cost of making a 100g bar of plain milk chocolate.

The main culprit for soaring costs was the rocketing price of cocoa butter, which has been hit by adverse weather in the Ivory Coast - one of the most important growing countries.