Table 3.

Summary of study intervention characteristics for prevention of development of T2DM

Study/Ref	Intervention characteristics	Intensity, duration, and regularity
Da-Qing, China [29, 30]	Intervention groups—received individual/small-group counseling, delivered by trained physicians, nurses, and technicians	1 individual counseling session
	Diet group—those with body mass index (BMI) of ≥25 kg/m2 advised to lose weight, through goal setting on healthy diets. Those with BMI of <25 kg/m2 encouraged to eat healthy diets with prescribed proportions of carbohydrates, fat, and protein	Weekly small-group counseling sessions for 1 month, monthly for 3 months and then once every 3 months
	Exercise group—advised to increase amount of leisure time physical exercise
	Diet + exercise group—received both interventions as above
	Control group—received usual care (general information on diabetes/IGT, brochures containing information on improving diet/physical activity)
IDPP-1, India [31, 40]	Intervention groups—received individual counseling, followed up by telephone	1 individual counseling at the beginning of the study
	Lifestyle group—those performing “moderate” activity (physical labor/walk or cycle for >30 min/day/perform exercise regularly) advised to continue routine activities. Those performing sedentary/light physical activity advised to walk briskly for ≥30 min/day
		Telephonic contact after 2 weeks or by letter
	Advice on diet modification given, including reduction in total calories and refined carbohydrates/fats, avoidance of sugar, and inclusion of fiber-rich foods	Monthly telephonic contacts personal sessions at 6 monthly intervals
	Metformin group—received metformin tablets for 3 months and provided diaries to record daily intake of tablets
	Lifestyle + metformin group—received both interventions as above
	Control group—received advice on standard healthcare
Community based, India [32]	Individual face-to-face culturally sensitive (Tamil language) educational sessions on dietary modification (increasing fiber, reducing fat, portion control), increasing physical activity, and relaxation breathing techniques conducted	10 face-to-face individual education sessions
		Group events for reinforcement
	Group events, such as cooking/physical activity demonstrations, organized as reinforcement	Additional counseling sessions for individuals with impaired FBG