High Glycemic Index Starch Promotes Hypersecretion of Insulin and Higher Body Fat in Rats without Affecting Insulin Sensitivity

Abstract

In rats, prolonged feeding of high glycemic index (GI) starch results in basal hyperinsulinemia and an elevated insulin response to an intravenous glucose tolerance test (IVGTT). The aim of this study was to assess hepatic and peripheral insulin resistance (IR) using euglycemic hyperinsulinemic clamps. Insulin sensitivity, epididymal fat deposition and fasting leptin concentrations were compared in rats fed isocalorically a low or high GI diet for 7 wk (45% carbohydrate, 35% fat and 20% protein as energy) or a high fat diet (20% carbohydrate, 59% fat and 21% protein as energy) for 4 wk so that final body weights were similar. At the end of the study, high GI rats had higher basal leptin concentration and epididymal fat mass than the low GI group, despite comparable body weights. High GI and high fat feeding both resulted in the higher insulin response during IVGTT, but impaired glucose tolerance was seen only in rats fed high fat. The GI of the diet did not affect basal and clamp glucose uptake or hepatic glucose output, but high fat feeding induced both peripheral and hepatic IR. The findings suggest that hypersecretion of insulin without IR may be one mechanism for increased fat deposition in rats fed high GI diets. J. Nutr. 131: 99 -104, 2001.

A Low-Glycemic Load Diet Facilitates Greater Weight Loss in Overweight Adults With High Insulin Secretion but Not in Overweight Adults With Low Insulin Secretion in the CALERIE Trial

“…However, the influence of postchallenge hyperinsulinemia on weight loss may be particularly important for specific dietary compositions, in particular diets that differ in glycemic load or glycemic index, as suggested by animal studies (31)(32)(33). High-glycemic load diets increase postprandial hyperinsulinemia, which favors fatty acid uptake, inhibition of lipolysis, and energy storage leading to weight gain (34).…”

Metabolic effects of diets differing in glycaemic index depend on age and endogenous glucose-dependent insulinotrophic polypeptide in mice

“…Indeed, the only available long-term prospective cohort study investigating potential effects of diets differing in GI in aged participants (mean age 71 years) showed no associations of the GI both with metabolic markers and risk of coronary heart disease [12]. Notably, also in rodents the reported beneficial effects of low vs high-GI diets are exclusively derived from studies exposing young animals [1,[13][14][15][16][17][18] or, in the only available long-term study, beginning the dietary intervention in young age [2].…”

A comparison between an in vitro method to determine carbohydrate digestion rate and the glycemic response in young men

“…The postprandial glucose and insulin levels are physiological responses which, according to some authors, are directly related with the prevalence of chronic non-transmissible diseases, such as obesity, diabetes and cardiovascular diseases (Pawlak et al, 2001;Jarvi et al, 1999;Sigal et al, 1997;Despres et al, 1996). When these responses are raised over a long period of time, insulin resistance may result, thus increasing the risk of developing these diseases (Wiseman et al, 1996;Hyggins et al, 1996;Byrnes et al, 1995).…”