Elsevier

The Journal of Nutrition

Volume 139, Issue 10, October 2009, Pages 1881-1889
The Journal of Nutrition

Dietary Starch Type Affects Body Weight and Glycemic Control in Freely Fed but Not Energy-Restricted Obese Rats1,2,3

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Abstract

This study comprised 2 experiments that tested the hypothesis that a high-amylose starch diet (AMO) would improve body weight and glycemic control relative to a high-amylopectin starch diet (AMN) in rats with diet-induced obesity. After inducing obesity with a high-fat and -energy diet (Expt. 1), male Sprague-Dawley rats (n = 46) were divided into 4 groups and given free or restricted access to either an AMN or an AMO diet for 4 wk (Expt. 2). After 3 wk, rats from each group underwent an oral glucose tolerance test. At the end of the experiment, food-deprived rats were killed by decapitation and blood and tissues were collected for analyses. AMO led to lower total energy intake, weight gain, fat pad mass, and glycemic response but higher insulin sensitivity index than AMN, only when consumed ad libitum (AL) (P < 0.05). AMO led to higher glucagon-like peptide-1 and peptide YY responses and mRNA levels, independent of feeding paradigm (P < 0.01). The mRNA levels of key neuropeptide systems involved in the regulation of food intake were affected only by energy restriction. On the other hand, AMO resulted in higher expression of uncoupling protein-1 in the brown adipose tissue than AMN in rats that consumed food AL (P < 0.05). The effects of AMO appear to be mediated by its high resistant starch content rather than its glycemic index. We conclude that starches high in AMO can be effective in weight and glycemic control in obesity.

Abbreviations used:

AL
ad libitum
AMN-AL
rats that consumed the amylopectin diet ad libitum
AMN-ER
energy-restricted rats fed the amylopectin diet
AMO-AL
rats that consumed the amylose diet ad libitum
AMO-ER
energy-restricted rats fed the amylose diet
AUC
area under the curve
BAT
brown adipose tissue
CTR
control
DIO
diet-induced obesity
DR
diet resistant
ECG
endogenous control gene, ER, energy restricted/restriction
GI
glycemic index
GLP-1
glucagon-like peptide-1
GOI
gene of interest
HFE
high fat and energy diet
iAUC
incremental AUC
OGTT
oral glucose tolerance test
PGC
proglucagon
POMC
proopiomelanocortin
PTP1B
protein tyrosine phosphatise 1B
PYY
peptide YY
QUICKI
quantitative insulin sensitivity check index
RS
resistant starch
SOCS-3
suppressor of cytokine signalling 3
tAUC
total area under the curve
TEI
total cumulative energy intake
UCP-1
uncoupling protein-1
WAT
white adipose tissue

Cited by (0)

1

Supported by Health Canada.

2

Author disclosures: A. A. Aziz, L. S. Kenney, B. Goulet, and E. S. Abdel-Aal, no conflicts of interest.

3

Supplemental Tables 1 and 2 are available with the online posting of this paper at jn.nutrition.org.