Marks & Spencer has restructured its senior food team, promoting Andy Adcock to the newly created role of trading director for food.

Adcock was formerly commercial director alongside Jim Waller, who has now decided to leave M&S.

Waller joined the retailer in 2001 and made headlines in 2008 when he said that M&S was considering launching a food offer online using a model similar to Waitrose and Ocado, and described M&S as “fat” and “complacent”.

An M&S spokeswoman said: “Jim leaves with our thanks for his significant contribution to our food business over the last 10 years and has our best wishes for the future.”

Adcock will report to John Dixon, who has been rebuilding M&S’s strength in the food category.

When the retailer last updated in April, it reported a 3.4% increase in food like-for-likes and a 10 basis point improvement in market share to 3.8%. M&S has increased its emphasis on new products – 1,900 new lines have been launched over the past year, representing more than 25% of the entire food range.

Singer analyst Matthew McEachran said Dixon’s “aggressive” approach to turning around M&S’s food business had been key. Initiatives such as ‘Dine in for two for £10’, while not very profitable, have been important footfall drivers and brought in new customers.

The changes in management are the latest at M&S, which last week named Mars executive Damian Guha trading director for home and poached John Lewis head of strategy and international development Robert Weston to become brand director for food.

M&S posts full-year results on May 24 and on Wednesday its share price reached 400p for the first time since last autumn. The figure is talismanic because it was what Sir Philip Green was willing to pay to take control of M&S in 2004.

McEachran said M&S generally seemed to be making progress under the leadership of chief executive Marc Bolland. “So far, so good but it’s a long burn,” he said.