Equilibrium theory of erosional slopes approached by frequency distribution analysis; Part 1

<h3>Background</h3> There is limited evidence that nutritional labelling on food/drinks is changing eating behaviours. Physical activity calorie equivalent (PACE) food labelling aims to provide the public with information about the amount of physical activity required to expend the number of kilocalories in food/drinks (eg, calories in this pizza requires 45 min of running to burn), to encourage healthier food choices and reduce disease. <h3>Objective</h3> We aimed to systematically search for randomised controlled trials and experimental studies of the effects of PACE food labelling on the selection, purchase or consumption of food/drinks. <h3>Methods</h3> PACE food labelling was compared with any other type of food labelling or no labelling (comparator). Reports were identified by searching electronic databases, websites and social media platforms. Inverse variance meta-analysis was used to summarise evidence. Weighted mean differences (WMD) and 95% CIs were used to describe between-group differences using a random effects model. <h3>Results</h3> 15 studies were eligible for inclusion. When PACE labelling was displayed on food/drinks and menus, significantly fewer calories were selected, relative to comparator labelling (WMD=−64.9 kcal, 95% CI −103.2 to −26.6, p=0.009, n=4606). Presenting participants with PACE food labelling results in the consumption of significantly fewer calories (WMD=−80.4 kcal, 95% CI−136.7 to −24.2, p=0.005, n=486) relative to comparator food labelling. <h3>Conclusion</h3> Based on current evidence PACE food labelling may reduce the number of kilocalories selected from menus and decrease the number of kilocalories/grams of food consumed by the public, compared with other types of food labelling/no labelling. <h3>Trial registration number</h3> CRD42018088567.