Growth in sales of non-food items such as clothes and household items helped supermarket operator J Sainsbury post a healthy rise in like-for-like sales in the 11 weeks to March 20.Like-for-like sales - a measure that excludes the impact of new openings - rose by 4.8% compared with the same period a year ago, or by 1.7% excluding fuel.New openings as Sainsbury's continues expanding, particularly in parts of the country where it is less well represented, helped total sales rise by 7.1%, or by 4.4% excluding the impact of fuel. Sales of non-food items grew at three times the rate of food, the company said.'We are now serving over 19m customers on average per week, up one million on last year,' said chief executive Justin King, who also predicted tough times this year.'While we expect the consumer environment to remain challenging in 2010, our universal customer appeal together with our accelerated growth of space for new supermarkets, extensions and convenience stores means we are well placed to make continued good progress in the new financial year.'