Super-sizing Supermarkets?

Everyone (including the UK government) appear to accept that the country has an 'obesity epidemic' with dire health and costs consequences (https://www.theguardian.com/society/2018/jun/24/helm-boseley-health-diet-eating-obesity-policy-eating-sugar-salt-fat). The latest focus appears to be the activities of supermarkets (especially displays in the check-out aisles). Supermarkets (and other shops and on-line suppliers?) certainly can play a role in countering the intake of too many calories, too much unhealthy food and giving the buying public more information on healthy choices. Having said that, they are in the business of selling stuff, so expecting them to 'police' health is, I feel, expecting too much (especially if we rely on 'voluntary' actions). It seems to be that the government needs to be more pro-active and should be legislating to help parents provide the appropriate nutrition (and exercise?).