Table 1.

Examples of text messages sent to the intervention group.

Text message category	Example text message
Introductory	Hi [pref_name]a, welcome to the TEXTBITESb study. We hope you find the program fun and helpful. If you have any questions throughout the program, text us or call. We are here to support you! If you ever want to stop the messages, respond STOP to opt-out.
Physical activity	Need a dose of some happy hormones? Stretching can release endorphins, reduce your stress and make you feel great. The best part? You can do it anywhere, even while watching TV or YouTube. Check it out: tinyurl.com/stretchyout.
Nutrition	Corn isn’t just a tasty snack, it’s multi-purpose! It can be used to make fireworks, glue, paint & plastic. But let's face it, popcorn is one of the best uses, check out some recipe ideas here: tinyurl.com/airpopcorn.
Mental wellbeing	Your brain has 86 billion thinking cells (called “neurons”) & 80 billion or so supporting cells. Wow, that's a lot! No wonder they need a break at night to rest & recover. Make sure to give them 8-10 hours rest each day!
General behaviors	Want to get your homework or study done in record time? Do power bursts! Put your phone on do not disturb and power it out for 25 min. Take a 5 min break (yep, you can check your phone) and repeat until your work is done!
Health counselor	How is everything going, [pref_name]? Text back if you would like to chat with our health counsellor about all things food, exercise and wellbeing and we will get back to you soon.
Final	This is your last message from the TEXTBITES study. Thank you for being a part of the program, we couldn’t have done it without you! We will contact you shortly to arrange your 6-month follow-up interview. Thanks again from the TEXTBITES study team!

^apref_name: participants preferred first name

^bTEXTBITES: TEXT message Behavioral Intervention for Teens on Eating, physical activity, and Social wellbeing