Types of identified restrictions: city-wide bans on new fast food outlets; creation of 'super zones' around schools to restrict presence of fast-food or unhealthy food outlets.

What we know: Few evaluations have occurred for these types of policies but evidence of effectiveness to support the implementation of super zones has been reported in the Canadian context. Canadian children at schools located more than 500m from convenience stores and fast-food outlets were found to have fewer dental caries (MacKenbach et al., 2022).

Examples of implementation: In 2008, Los Angeles (USA) piloted a ban on new fast-food establishments for one year. London (UK) has also piloted the implementation of 400m super zones around schools in an attempt to restrict unhealthy food consumption (Danielli et al., 2021).

Types of identified policies: bans on trans fat; food fortification (e.g., folic acid, iodine); salt reductions; restrictions on caffeine content (for energy drinks); mandatory food reformulation; substitution of trans fat with polyunsaturated fatty acids; limits on trans fats in restaurants.

What we know: Both bans on trans fat and mandatory reformulation to eliminate trans fat have been highly effective (Hyseni et al., 2017) and mandatory reformulation is associated with greater reductions in consumption than voluntary reformulation approaches (Hyseni et al., 2017; Burgaz et al., 2023). Food fortification (e.g., with folic acid, iodine) has been effective for tackling undernutrition and food insecurity (Burgaz et al., 2023) and reduce the prevalence of orofacial clefts (MacKenbach et al., 2022). Mandatory salt reduction via legislation and substituting trans fat with polyunsaturated fatty acids were both cost-effective (Singh et al., 2018). Mandatory limits on trans fats within restaurants was associated with significant levels of switching to trans fat-free oils in restaurants and increases to the amount of trans fat-free meals purchased (Downs et al., 2017).

Examples of implementation: Within Denmark, implementation of a mandatory reformulation policy to eliminate trans fat has been highly effective in Denmark (Hyseni et al., 2017). In New York City (USA), the implementation of a mandatory limit on trans fats for foods within restaurants caused almost universal (98%) adoption of trans fat-free oils (compared to 50% of restaurants pre-implementation) and an increase in purchased trans fat-free meals by 86% (Downs et al., 2017).

Types of identified policies: price reductions and/or subsidies for fruit, vegetables and water; VAT reduction/removal for fruits and vegetables; vouchers; food benefit programmes.

What we know: Price reductions and subsidies of healthier foods, especially when combined with taxation or price increases of unhealthier options, were generally effective for encouraging sales of healthier foods (Hillier-Brown et al., 2017a; Burgaz et al., 2023; Browne et al., 2020; Naik et al., 2019). Reported actions within these reviews ranged from price reductions, alongside signposting , and vouchers for, fruit and vegetables (F&V) to VAT reduction or removal for fruit and vegetables and benefits programmes via food banks. Effects of these fiscal measures on obesity and NCD-related outcomes are more limited and mixed, with greater evidence around changes in healthier purchasing behaviours and sales as well as positive effects on undernutrition and food insecurity (Burgaz et al., 2023). Financial incentives for purchasing fruit and vegetables have been shown to increase household fruit and vegetable purchases or adult fruit and vegetable intake when targeted at welfare recipients (Moran et al., 2020) and Indigenous, rural and remote communities (Browne et al., 2020), yet these positive results may at times be timebound to the intervention period, dependent on the magnitude and promotion of the discounts and not necessarily indicative of substitution or improved dietary quality among participating populations.
"Complementary interventions focused on changing policies or environments to reduce unhealthy food purchases appear more effective in improving total diet quality at the population level than nutrition or cooking education, which tend to have low participation [51,52,59,61,63]" (Moran et al., 2020, p. 9).

What we know: Well-established evidence indicates that exposure to high fat, salt and/or sugar (HFSS) food and beverage advertising can negatively impact health through increasing appeal, purchasing and/or consumption of HFSS products (Danielli et al., 2021; Love et al., 2022; MacKenbach et al., 2022; Pereira et al., 2021; Burgaz et al., 2023; Hyseni et al., 2017; Chung et al., 2021). Current evidence suggests that banning advertising for energy drinks, which can have high levels of caffeine and sugar, can reduce energy drink consumption (Rostami et al., 2024).

What we know: Limited evidence has explored the individual efficacy of policies requiring mandatory food waste prevention measures within catering settings, but one cited review by Burgaz et al., (2023) found overall positive effects on improving environmental sustainability for food waste prevention measures that included the optimisation of planning systems to reduce overproduction and donation of leftovers to local food banks (Burgaz et al., 2023).