The number of people eating out fell from 71 to 69 per cent year-on-year within a two week period.
Average spend dropped from £12.72 to £12.54 per meal, down on a June 2013 high of £13.30.
A third of respondents reported that they had not eaten out in the past two weeks due to expense, lack of time and healthy eating and hygiene concerns.
However Horizons said the overall trend in the eating out marketing remained positive.
“The slight dips that we are seeing in pockets of the eating out market suggests that some consumers, particularly the squeezed middle, are choosing to spend their money elsewhere,” commented Horizons’ foodservice analyst Nicola Knight.
“We are comparing this year’s figures with those of 2014, which was a particularly strong year for eating out - it’s important to remember that the overall trend is positive and the market is stronger than it was three years ago.”
The decline was particularly marked amongst the 35-44 age group, with 62 per cent eating out in June – down ten per cent on 2014.
“The 35-44 age group are those most likely to have the biggest financial ties – often having dependent children, house moves to pay for and foreign holidays to save for,” said Knight.
“If this age group is once again starting to spend on higher ticket items like these it might be that eating out becomes one of those expenses they are prepared to forego temporarily.”
18-34 year olds ate out most frequently, with 77 per cent of respondents in the age group saying they had dined out in the previous two weeks.
Over 55’s are also starting to eat out more often, with 67 per cent doing so in June, up two per cent year-on-year.
Horizons surveyed 2,024 adults between 19-21 June 2015.