Objective: To investigate the effectiveness of intensive innovative methods for implementing dietary prescriptions on weight management and glycaemic control in overweight men with Type II diabetes.
Design: A randomised clinical trial with a 12-week intervention period - three isocaloric dietary intervention groups (intermittent energy restriction, pre-portioned meals and self-selected meals) each with weekly dietitian contact - and a follow-up visit after 18 months.
Subjects: A total of 51 men with Type II diabetes (mean age 54 y, mean body mass index (BMI) 31.7 kg/m(2)).
Measurements: Weight, body composition, waist circumference, glycaemic control (HbA(1c)) and blood lipids.
Results: For all subjects, intensive diet therapy over the 12-week intervention period resulted in a mean reduction in energy intake of 2360+/-2780 kJ/day (564+/-665 kcal/day) and significant reductions in weight (6.4+/-4.6 kg), waist circumference (8.1+/-4.6 cm), percent body fat (1.9+/-1.5%), HbA(1c) (1.0+/-1.4%) and triglyceride levels (0.3+/-0.6 mmol/l) compared to baseline levels. Intervention group did not affect clinical outcomes, with the exception of percent body fat. A total of 27 (52.9%) subjects attended the 18-month follow-up visit. At this visit, none of the improvements in clinical parameters was maintained, with all parameters returning to preintervention levels.
Conclusions: : A dietary prescription of 6000-7000 kJ/day (1400-1700 kcal/day) was effective in achieving a 6% weight loss and improving glycaemic control. The method of implementation made no difference to the outcomes between groups at 12 weeks or 18 months. Thus, we propose that it was the intensive weekly contact with a health professional in combination with moderate energy restriction that facilitated the successful short-term results seen.