Influence of fat and carbohydrate proportions on the metabolic profile in patients with type 2 diabetes: a meta-analysis.
OBJECTIVE
The effects of dietary macronutrient composition on metabolic profiles in patients with type 2 diabetes have been inconsistent. This meta-analysis aimed to elucidate the effect of replacing dietary fat with carbohydrate on glucose and lipid parameters in patients with type 2 diabetes.


METHODS
We searched for randomized trials that investigated the effects of two kinds of prescribed diets (a low-fat, high-carbohydrate [LFHC] diet and a high-fat, low-carbohydrate [HFLC] diet); in these studies, energy and protein intake did not differ significantly between the two dietary groups. Nineteen studies that included 306 patients met our inclusion criteria. Median diet composition of carbohydrate/fat in the LFHC and HFLC diets was 58%/24% and 40%/40%, respectively.


RESULTS
Changes in values for A1C, fasting plasma glucose (FPG), and total and LDL cholesterol did not differ significantly between the LFHC and HFLC groups. However, the LFHC diet significantly increased fasting insulin and triglycerides by 8% (P = 0.02) and 13% (P < 0.001), respectively, and lowered HDL cholesterol by 6% (P < 0.001) compared with the HFLC diet. There were positive associations among the magnitude of changes in FPG, fasting insulin, and triglycerides for the diets analyzed. However, stratified analysis indicated that the increase in triglycerides was insignificant when accompanied by energy intake restriction.


CONCLUSIONS
Our findings suggested that replacing fat with carbohydrate could deteriorate insulin resistance while the adverse effect on triglycerides from the LFHC diet could be avoided by restricting energy intake to a degree sufficient for the attainment of weight reduction.
Kodama
Satoru
S
Department of Lifestyle Medicine and Applied Nutrition, Ochanomizu University, Tokyo, Japan.
Saito
Kazumi
K
Tanaka
Shiro
S
Maki
Miho
M
Yachi
Yoko
Y
Sato
Mutsumi
M
Sugawara
Ayumi
A
Totsuka
Kumiko
K
Shimano
Hitoshi
H
Ohashi
Yasuo
Y
Yamada
Nobuhiro
N
Sone
Hirohito
H
D001786:Blood Glucose / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D050528:Diet, Carbohydrate-Restricted; D003927:Diet, Diabetic; D018752:Diet, Fat-Restricted; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D012680:Sensitivity and Specificity
D001786:Blood Glucose; D008076:Cholesterol, HDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D006442:Glycated Hemoglobin; D007328:Insulin; D008055:Lipids