Which? placed West Dunbartonshire behind two London local authorities and one in Kent as it claimed some are struggling to ensure businesses comply with food safety rules.
It ranked them on three criteria: the proportion of high or medium-risk premises that were "broadly compliant" with food hygiene requirements, the percentage of premises that had received a risk rating, and the proportion of inspections and other follow-ups required that were actually carried out.
The study found that of the 749 establishments in West Dunbartonshire, 98.7% had been rated for risk and less than half [45.6%] were broadly compliant. It carried out inspections and follow ups in 99.4% of cases.
The survey also rated Orkney as the best area in Scotland for food safety enforcement.
Across the UK, Which? found a third of high and medium-risk food businesses were not abiding by hygiene rules, while work to check standards such as the accuracy of food labels was described as "patchy". The organisation said the report placed fresh doubts on the food industry following last year's horsemeat scandal.
Bexley in south-east London is the poorest-performing local authority, with five other London councils in the bottom 10, according to the research, which took into account premises such as hospitals, care homes, restaurants, takeaways, retailers and food suppliers.
Cherwell District Council in north Oxfordshire came top out of 395 local authorities in the UK.