Background Mandatory calorie labelling on menus of large out-of-home food outlets was implemented in England in April 2022. Early quantitative findings indicate implementation was not associated with a change in calories purchased or consumed. We conducted post-implementation interviews to understand the experience and process of implementation and enforcement of the calorie labelling regulations and provide additional context for interpretation of quantitative findings.

Methods Using purposive sampling, we recruited 11 employees of large food businesses (regulation implementers) and 9 of local authority (LA) environmental health or trading standards departments (regulation enforcers). Semi-structured interviews directed by topic guides were conducted by video conference and lasted up to 60 minutes. Interviews were audio recorded, transcribed verbatim and analysed using the Framework Method.

Results Interviews revealed interdependent economic, regulatory, business, and consumer contexts that together may explain the success, or lack thereof, of the policy. Implementers reported that calorie labelling was implemented at a time of global financial pressure, making extra resource demands on businesses during an already difficult time.

Both groups of participants described a decentralised approach to delivery and enforcement, whereby delivery was primarily carried out by businesses partnering with LAs. Resource constraints meant LAs were not equally able to assist with business inquiries.

Participants reported little enforcement activity and few complaints about calorie labels. Calorie labelling was perceived by enforcers as low priority (‘somewhere near the bottom’) compared to acute food threats such as allergens; LAs were not provided with additional support; and pre-implementation discussions with businesses created ‘presumed compliance.’ Businesses complied because they did not want to ‘lose customers’ trust.’

Participants were generally supportive of the idea of calorie labelling but described reasons why they thought it would have little impact on consumer behaviour. These included a presumed lack of consumer interest, an unhealthy food environment that labelling would not change, ingrained eating habits, lack of additional messaging about how consumers should use calorie labels and a financial context that may encourage consumers to focus on ‘full bellies’ and ‘value-for-money’ over health.

Conclusion Despite financial challenges, large businesses implemented calorie labelling in partnership with LAs. Resource constraints meant LAs engaged in little enforcement activity, relying instead on pre-implementation partnerships with businesses. LAs require additional resources to carry out effective enforcement activity. Several reasons for the limited impact on consumer purchasing and consumption were raised. We did not conduct interviews with central government policymakers or consumers who would both likely provide useful additional insights.