[1] Queen Margaret Univ, Dept Psychol, Edinburgh, Midlothian, Scotland
[2] Ryerson Univ, Dept Psychol, Toronto, ON, Canada
[3] York Univ, Milton & Ethel Harris Res Initiat, Toronto, ON M3J 2R7, Canada
[4] Royal Hosp Sick Children, Dept Paediat Diabet, Edinburgh EH9 1LF, Midlothian, Scotland
[5] Univ Plymouth, Dept Dietet, Plymouth PL4 8AA, Devon, England
[6] Univ Edinburgh, Dept Child Life & Hlth, Edinburgh, Midlothian, Scotland