Table 2 Contextual drivers across the COM-B components and TDF domains

CAPABILITY

Psychological

Knowledge

• Awareness of the benefits of healthy eating and the harms of sugar ( +)

• School staff’s awareness of nationwide efforts against sugar ( +)

• Perceived limited memory span of children to retain long-term health knowledge (-)

• School staff’s lack of awareness of guidelines on food and beverages (-)

You can explain to the kids why [ultra-processed foods are harmful], we talk about constipation, flavorants, and colorants… at that time they are like WOW. But after a day is like they have forgotten

(Deputy principal, fee-paying school)

Behavioural regulation

• Lack of adherence to food and beverage guidelines by children, school tuckshops, and vendors outside of schools (-)

Vendors have the contract with the school governing body. It is for them to stick to what the school wants to be sold […] but they will always sometimes go out of way

(Principal, no-fee school)

Physical^a

OPPORTUNITY

Physical

Environmental context and resources

• Lack of school infrastructure to promote healthier eating (i.e., taps, covered eating space, fridges, gardens) (-)

• Lack of affordable fresh nutritious foods in schools (-)

• Cheap and unhealthy foods and beverages at school tuckshop (-)

• Influence of product characteristics (i.e., shelf life, pricing) on tuckshop stock (-)

• Mismatch of school location, children needing support and National School Nutrition Programme allocation policy (-)

Instead of the acidic drinks we could have fruit juice and it would be good to have some water been sold at the school. Like today, we don’t have water in the taps

(Deputy principal, fee-paying school)

I used to have apples and stuff like that, but they didn’t sell. A child doesn’t want to pay R3.00 [$0.163] for an apple they rather pay R3.00 for an ice-tea

(Tuckshop manager, fee-paying school)

I don’t stock yoghurts and fruit juices because of the sell date. These take a long a time to sell and if the sell by date is gone, I have to take it off the shelve. Then the school has to bear the loss

(Tuckshop manager, fee-paying school)

Organisational culture/

climate

• Acknowledged support from donors ( ±)

• School’s reward culture using unhealthy foods (-)

• Presence of school food and beverage rules and regulations ( +)

• Food and beverage monitoring efforts (lunch tins by staff, official health inspections) ( +)

• Presence and influence of a school governing body ( +)

Because it is a donation, we don’t have the right to demand anything. They [donors] send fruits, juice, cold drinks, so it depends on what the donation is that those kids get

(School tuckshop manager, fee-paying school)

We sit down with them [vendors] and tell them what we expect them to sell here at school

(School nutrition coordinator, no-fee school)

We have it in our school code of conduct they may not bring any cold drinks / gassy cold drinks to school

(Deputy principal, fee-paying school)

Social

Social influences

• Children’s and caregivers’ brand recognition of unhealthy drinks and foods (-)

• Social norms for unhealthy eating and inactivity influence on children (peers and households) (-)

There are some kids who really go for the brand name, and they want the real coke

(School tuckshop manager, fee-paying school)

It doesn’t help if you have a policy of “only healthy food” and your children is brought up at home with coke, chocolate, and cake. Then you are banging against a closed door

(School tuckshop manager, fee-paying school)

MOTIVATION

Automatic

Emotions

• Tuckshops’ fear of loss of profit if stocking healthy vs unhealthy foods (-)

• Fear of children getting sick from vendor foods ( ±)

• School staff’s fear of negatively influencing livelihoods of vendors (-)

• School staff’s and tuckshops’ feeling of pointlessness, discouragement due to lack of collective action among food outlets (-)

• Children’s and caregivers’ individual preference for unhealthy over healthy foods (-)

This is a profit-making business and she [tuckshop manager] is going to sell what the children want in order for her to survive, because she pays the school rent. So, she is going to sell the wrong [unhealthy] things

(Principal, fee-paying school)

It is difficult because I can’t be the only one implementing that [healthy options] and everybody around me is not

(School tuckshop manager, fee-paying school)

Reflective

Roles and identity

• Convenience and affordability of unhealthy food guides caregivers’ food provisioning, and children’s purchasing (-)

• Association of wealth status and unhealthy foods (-)

• Stigma associated with National School Nutrition Programme (-)

• Caregiver’s perception of school’s sole responsibility to ensure healthy diets for children (-)

What are the quickest things to give children and what children like is chips and sweets and a cold drink. All processed foods but the quickest. The easiest way for parents

(Principal, fee-paying school)

The more take away [junk food] you can, buy it shows wealth, if you got like McDonald

(Deputy principal, fee-paying school)

Beliefs (of interviewees) about capability

• Difficulty of implementation of school policies (-)

• Difficulty to control vendors outside of school premises (-)

• Perceived inability of younger children to control their health (-)

• Difficulty of breaking children’s and caregivers’ unhealthy eating habits/mindsets (-)

Policies are brilliant on paper, not always easy to incorporate or to carry out but is important

(Principal, fee-paying school)

Outside the school it’s a challenge. There are people standing on the streets, selling, and we don’t have access to them saying that you must sell this and you mustn’t sell this. It's out of our control

(School nutrition coordinator, no-fee school)

Intention (of interviewees)

• School staff’s intent to encourage healthier dietary habits among caregivers and children ( +)

We sell your normal soft drinks and those are actually problematic because they also contain a lot of sugar. That is something we must actually look at and see if we can cut down on that

(Principal, fee-paying school)