During the time he presided over FFB, McNair (pictured) has seen a period of tremendous change in the UK food and drinks industry and leaves at a time when UK food and drink exports are predicted to reach their highest ever level at over £10bn.
McNair said: "It has been a real pleasure and privilege to lead FFB and to serve the British food and drink industry during this time.
"In particular, I would like to thank the great team of people FFB have in London and across the international office network for all their efforts during a period of exciting growth for the organisation.
" I am sure FFB will continue to go from strength to strength assisting the market development of its clients both within the UK and internationally."
FFB chairman, Lady Sylvia Jay, said: "David has worked hard for Food from Britain and consistently met the targets set for him and the organisation.
"His extensive knowledge of the British food and drink industry worldwide has served FFB and its numerous clients well.
"He merits a more relaxed future and, on behalf of FFB's Council, I should like to thank him and to wish him every continued success in the years ahead."