Resistant starch and exercise independently attenuate weight regain on a high fat diet in a rat model of obesity

Center for Human Nutrition, Anschutz Medical Campus, University of Colorado Denver
Nutrition & Metabolism (Impact Factor: 3.26). 07/2011; 8(1):49. DOI: 10.1186/1743-7075-8-49
Source: PubMed


Long-term weight reduction remains elusive for many obese individuals. Resistant starch (RS) and exercise may be useful for weight maintenance. The effects of RS, with or without exercise, on weight regain was examined during relapse to obesity on a high carbohydrate, high fat (HC/HF) diet.
Obesity-prone rats were fed ad libitum for 16 weeks then weight reduced on a low fat diet to induce a 17% body weight loss (weight reduced rats). Weight reduced rats were maintained on an energy-restricted low fat diet for 18 weeks, with or without a daily bout of treadmill exercise. Rats were then allowed free access to HC/HF diet containing low (0.3%) or high (5.9%) levels of RS. Weight regain, energy balance, body composition, adipocyte cellularity, and fuel utilization were monitored as rats relapsed to obesity and surpassed their original, obese weight.
Both RS and exercise independently attenuated weight regain by reducing the energy gap between the drive to eat and suppressed energy requirements. Exercise attenuated the deposition of lean mass during relapse, whereas its combination with RS sustained lean mass accrual as body weight returned. Early in relapse, RS lowered insulin levels and reduced the deposition of fat in subcutaneous adipose tissue. Exercise cessation at five weeks of relapse led to increased weight gain, body fat, subcutaneous adipocytes, and decreased lean mass; all detrimental consequences to overall metabolic health.
These data are the first to show the complimentary effects of dietary RS and regular exercise in countering the metabolic drive to regain weight following weight loss and suggest that exercise cessation, in the context of relapse on a HC/HF diet, may have dire metabolic consequences.

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    • "The fermentation process and its potential nutritional benefits may therefore contribute to an enhanced health status, as well as reduction of starch digestibility (Minervini et al., 2010; Poutanen, Flander, & Katina, 2009). The increase in consumer demand for healthy, high quality foods in recent years has led to a growth in the use of new technologies as well as novel ingredients including RS. Wholegrain flour contains more RS than white (refined) flour and the health benefits of consumption of RS in the form of wholegrain products include its role as a prebiotic (Fuentes-Zaragoza et al., 2011; Slavin, 2013), a reduction in the incidence of chronic diseases, particular diabetes and colon cancer (Okarter & Liu, 2010) and weight loss (Higgins et al., 2011). Previous studies have indicated that processing conditions can affect the formation of RS by influencing the gelatinisation and retrogradation of normal starch (Johansson, Siljestrom, & Asp, 1984; Thompson, 2000). "
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    • "We have shown previously that moderate to high levels of RS (as 20% HAMS providing 6% RS) reduced the body weight of healthy non-obese rats compared to those fed a low-amylose control diet [7]. A study by Higgins et al. [8] also showed that a diet containing 13% HAMS reduced adiposity but not weight regain in diet-induced obese rats. Because dietary intakes of RS in industrialised countries are low, it is important to establish minimal levels of RS that elicit favourable metabolic effects in obese and non-obese animals to assist in identifying appropriate levels for human intervention trials. "
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