Almost a quarter of Aberdeen’s food businesses were given an “improvement required” rating - the worst in Scotland - at their last inspection, while in Edinburgh, one in five were told improvements needed to be made.
In Dundee, 16 per cent of restaurants and takeaways were given the lower rating by inspectors, alongside 18 per cent of those located in the Highlands, according to the study from consumer watchdog Which?.
However, those in Stirling had a near-perfect 98 per cent of food businesses rated “pass”, while in Orkey, less than one per cent were told to improve measures.
Which? is calling for it to be mandatory for food businesses to display their food hygiene ratings - which it is currently not in Scotland and England but is in Wales and Northern Ireland - making it much harder for consumers to find out if a restaurant or takeaway has acceptable food hygiene standards.
In Scotland, unlike England, where there is a five star system, restaurants are handed either a “pass” or “improvement required” rating - meaning those which do not pass could have infringed just one small requirement - or demonstrated dangerous breaches in hygiene rules.
A number of well-known names in the Scottish restaurant trade have fallen foul of the inspections, including Michelin-starred eatery The Kitchin and sister restaurant Southside Scran, which were told to make improvements. At the time, a spokesman for the restaurants said that the inspectors’ visit had “highlighted some procedural issues”.
Which? said that evidence suggests that making it a requirement for food businesses to display their hygiene rating can improve standards across the board. Since 2013, when the display of hygiene ratings became mandatory in Wales, the proportion of restaurants with five ratings has increased by 23 per cent.
When visiting a restaurant, inspectors consider the business’ food handling and preparation, how it manages food safety and the cleanliness of facilities, among other things.
The watchdog said it is concerned consumers risk being left in the dark or misled about hygiene standards and is calling for the mandatory display of hygiene ratings in food business across the whole of the UK, so consumers can make informed choices when dining out.
It added that all food businesses, including takeaways and restaurants, should be required to display an up to date food hygiene rating both on the premises and anywhere they have an online presence for customers ordering food from home, while the regulator should also be prepared to take strong action against food establishments displaying incorrect ratings that risk misleading consumers.
Lisa Barber, editor of Which? Magazine, said: “Our research has found that while some areas are blessed with impressive food hygiene levels across the board, others have large numbers of food businesses, including restaurants and takeaways, with sloppy standards that risk making customers seriously ill.
“There is strong evidence to suggest that food businesses up their game when they know they will have to prominently display their hygiene rating. It must urgently become mandatory for food businesses, including restaurants and takeaways, to display their score on the premises and online, so customers can make informed choices.”
England’s five worst areas for food hygiene were all in London.