Low-Glycemic Index Foods Improve Long-Term Glycemic Control in NIDDM

doi:10.2337/diacare.14.2.95

Low-Glycemic Index Foods Improve Long-Term Glycemic Control in NIDDM

Janette C Brand, PhD,
Stephen Colagiuri, MBBS, FRACP,
Shirley Crossman, BSc, CertDiet,
Annette Allen, RN,
David CK Roberts, PhD and
A Stewart Truswell, MD, FRCP

Human Nutrition Unit, Department of Biochemistry, University of Sydney; and the Department of Diabetes and Metabolism, Prince of Wales Hospital Randwick, New South Wales, Australia

Address correspondence and reprint requests to lanette C. Brand, PhD, Human Nutrition Unit, C08, The University of Sydney, Sydney, NSW 2006, Australia.

Abstract

Objective To compare high- and low-glycemic index (GI) diets in the treatment of non-insulin-dependent diabetes mellitus (NIDDM).

Research Design and Methods Sixteen subjects with well-controlled NIDDM and normal lipid profile, 10 of whom continued oral hypoglycemic medication, participated in the study. A diet that emphasized low-GI foods (e.g., porridge, pasta) was compared with a high-GI diet (e.g., processed cereals, potatoes). The GI of the low-GI diet was 15% lower than the high-GI diet (77 ± 3 vs. 91 ± 1) but otherwise similar in macronutrient composition and fiber, as determined by a 4-day weighed record. The diets were instituted under instruction from a dietitian who visited subjects at home on a weekly basis. Body weight was maintained within 1–2 kg.

Results Glycemic control was improved on the low-GI diet compared with the high-GI diet (statistically significant findings, P < 0.05). Mean glycosylated hemoglobin at the end of the low-GI diet was 11% lower (7.0 ± 0.3%) than at the end of the high-GI diet (7.9 ± 0.5%), and the 8-h plasma glucose profile was lower (area under the curve above fasting 128 ± 23 vs. 148 ± 22 mmol.h^-1.L^-1, respectively). Mean fasting plasma glucose, total cholesterol triglycerides, and lipoproteins did not show important differences.

Conclusions A low-GI diet gives a modest improvement in long-term glycemic control but not plasma lipids in normolipidemic well-controlled subjects with NIDDM.