Table 1.

Schedule for enrolment, interventions and assessments

Time point	Measurement	Evaluator	Enrolment	Allocation	T0	T1	T2
Screening			X
Informed consent			X
Allocation				X
Intervention group
TAU (medical diabetes treatment)				X	X	X	X
dbcoach (telephone coaching, app)				X	X	X	X
Control group
TAU (medical diabetes treatment)				X	X	X	X
dbcoach-app, written recommendation				X	X	X	X
Inclusion criteria
Age >18 years old	Screening	Study team	X
HbA1c>7.5 %	Screening	Physician	X
T2D according to ADA	Screening	Physician	X
Sufficient knowledge of German language	Screening	Physician	X
Access to ongoing diabetes care	Screening	Physician	X
Internet access	Screening	Study team	X
Physically inactive	Screening	Study team	X
Primary outcomes
HbA1c	Medical report	Physician			X	X	X
Objectively assessed physical activity	ActiGraph wGT3X-BT	Objective			X	X	X
Secondary outcomes
Self-reported physical activity	SIMPAQ questionnaire	Self-rating			X	X	X
Cognitive mediators of behaviour change	Sport related:	Self-rating
	Goal intention				X	X	X
	Self-concordance				X	X	X
	Consequence experience				X	X	X
	Barrier management				X	X	X
	Action planning				X	X	X
	Self-efficacy				X	X	X
Nutrition	Nutrition diary, Healthy Eating Index	Self-rating			X	X	X
Nutrition behaviour	SEV questionnaire	Self-rating			X	X	X
Quality of life	SF-8 questionnaire	Self-rating			X	X	X
Neuropathy	FACT questionnaire	Self-rating			X	X	X
Medication	Medical report	Physician			X	X	X
Food supplements	Medical report	Physician			X	X	X
Anthropometry	Medical report	Physician			X	X	X
Blood values	Medical report	Physician			X	X	X
Comorbidities	Medical report	Physician			X	X	X
Cost-effectiveness	Tarmed V.1.09	Study team			X	X	X
Demographic variables	Demographic questionnaire	Self-rating			X

ADA, American Diabetes Association; FACT, Functional Assessment of Cancer Therapy; HbA1c, glycated haemoglobin; SEV, Eating Behaviour Scale; SF-8, Short Form-8 Health Survey; SIMPAQ, Simple Physical Activity Questionnaire; TAU, treatment as usual; T2D, type 2 diabetes.