Randomized Controlled Trial of a New Dietary Education Program to Prevent Type 2 Diabetes in a High-Risk Group of Japanese Male Workers

Abstract

OBJECTIVE—The aim of this study was to assess the effectiveness of a new dietary education (NDE) program in reducing plasma glucose (PG) levels in Japanese male workers at high risk for type 2 diabetes through a randomized controlled trial. RESEARCH DESIGN AND METHODS—We randomly assigned 173 high-risk men (mean age, 55 years) to either the NDE or the control (conventional dietary education) group. Each subject in the NDE group received two individualized interventions especially aimed at reducing total energy intake at dinner by modifying dietary intake. The control group received conventional group counseling. An “overintake/underintake fraction” for total energy intake was used to measure the status of dietary intake. Our hypothesis was that the NDE group would have a 10% decrease in 2-h PG 1 year after the start of the education. Outcome measures were compared with ANCOVA by adjusting for baseline values. RESULTS—The NDE group had a significantly lower total energy intake at dinner and daily than the control group. The adjusted differences in changes from baseline in the absolute value of the “overintake/underintake fraction” were −15.3% (95% CI −24.6 to −6.0%, P = 0.002) for the NDE group and −6.0% (−9.8 to −2.2%, P = 0.002) for the control group. The NDE group had a decreased 2-h PG after 1 year, whereas that value was increased in the control group. The adjusted difference in the percent change of 2-h PG was significant (−15.2%, −22.0 to −8.4%, P < 0.001). CONCLUSIONS—The NDE was shown to reduce glucose levels in high-risk subjects for type 2 diabetes.