Power calculations were based on
data from a previous clinical trial of the
weight loss program(8) and biochemical
laboratory data in individuals with diabetes
(4). Using mean (SD) effect sizes of
6.8 (8.8) in the intervention groups and
2.0 (7.2) in the control group, there was
90% power for the primary aim with 75
participants per arm and a dropout rate
of up to 20%. There was also 90% power
to discern between-group HbA1c differences
of 0.5% (6 mmol/mol).