Table 1 Summary of interview topic guide

Introduction (5 min)

Warming up questions, to explore school Principal’s understanding of childhood obesity

1. What do the terms ‘overweight children’ and ‘obese children’ mean to you?

2. Do you think that overweight/obesity is an issue for children in China?

3. What about in your community, is it an issue here?

Topic 1 (5–10 min)

To gain insights into the Principal’s perceptions of the causes of childhood obesity

1. What do you think of primary school children’s dietary behaviour/pattern/habits in general?

2. What do you think of primary school children’s physical activity levels in general?

Topic 2 (5–10 min)

To understand the extent to which the Principal feels that schools should play an active role in promoting and supporting healthy eating and physical activity for the aim of preventing/controlling childhood obesity/overweight?

1. To what extent, do you think primary schools should play an active role in promoting healthy eating and physical activity in children?

2. Why?

Topic 3 (15 min)

To explore school’s current activities regarding healthy eating and/or physical activity promotion and the barriers encountered in implementing the activities

1. Does your school currently have any programme? If any, probe what/how they are going. If none, go directly to Topic 4.

2. Has the school met any difficulties or barriers in implementing the programme(s)?

Topic 4 (15 min)

1. To understand what schools want/need for playing a better role in children’s healthy behaviour promotion

1. What kind of resources or support, do you think would make it easier for your school to take an active role?

Probe: Have you had any experience in using these resources or support? How was the experience?

2. Summarising key points discussed and arisen to ensure data credibility