Mr King also warned he might remove tobacco from more stores in Scotland after he this week increased to 10 the number of cigarette-free stores following the imposition of the so-called Health Levy.
The supermarket giant, which recently achieved its highest market share for almost a decade at 16.7%, posted like-for-like sales growth of 1.7% for the six months to September 29.
Sainsbury's, which is relatively weak in Scotland where it is the market number four, has now recorded 31 consecutive quarters of like-for-like sales growth while rivals, including market-leader Tesco and Wm Morrison, have gone through periods of decline.
Mr King said: "Our performance is good in itself but also in the context of the market backdrop."
He said he expected changes in consumer behaviour, such as smaller and more frequent shopping trips, to continue as wage growth lags inflation.
"We see no uptick in disposable income in the year ahead," he said.
He also sought to play down reports that he is ready to exit Sainsbury's: "I do understand why, when someone's been in a job for eight years successfully, people think they'd have on their mind doing something else, but I'm very happy at Sainsbury's."
Mr King predicted retailers will compete by offering rival vouchers this Christmas. Sainsbury's claims its participation in Nectar card allows it to produce more targeted vouchers than rivals.
The chain's performance won plaudits from analysts.
Phil Dorrell of retail consultants, Retail Remedy, said: "Sainsbury's continues to go through the gears while others remain stuck in neutral."
However, concerns about widespread discounting at Christmas weighed on its shares which closed down 8.4p or 2.4% at 338.8p.
Sainsbury's operates around 70 stores in Scotland, around half of them convenience outlets.
But it no longer sells tobacco in 10 of them after complaining about the cost of a supplementary charge on business rates paid by large stores offering cigarettes and alcohol.
Mr King said: "We have taken the view we should not cross-subsidise the sale of cigarettes."
He said the chain will continue analysing all its stores and cut tobacco sales where it costs it money.
Sainsbury's Bank saw a 30% rise in new customers to its lending and insurance business, helping it increase its pre-tax profit contribution to the group to £12m, up from £7m last year.
The bank's management team was recently overhauled.
But finance director John Rodgers said it had no plans to follow Tesco Bank in offering current accounts and mortgages.