Dietary calcium exerts an anti-obesity effect, and dairy exerts about twice the activity as supplemental calcium. Milk contains angiotensin converting enzyme inhibitors (ACEi) and a high concentration of branched chain amino acids (BCAA), both of which may contribute to an anti-obesity effect through effects on lipid metabolism and muscle protein synthesis, respectively. To test this hypothesis, aP2-agouti transgenic mice were maintained for 6 weeks on an obesigenic soy based diet and then randomized into an ad libitum control group and energy restricted (70% of ad lib) diets containing soy protein (0.4% Ca), non-fat dry milk (NFDM; 1.2% Ca) or Ca-depleted NFDM (0.4% Ca) for an additional 6 weeks; the soy diet was provided with or without an ACEi and BCAA supplement and provided at either 0.4 or 1.2% Ca. The NFDM group exhibited ~2-fold greater reduction in body weight and fat than the energy restricted group (p<0.01), and the Ca-depleted milk group exerted 60% of the effect of intact milk (p<0.01); this effect was replicated by the ACEi/BCAA supplemented diet, and addition of calcium to this diet resulted in further weight and fat loss. Overall, the Ca, ACEi and BCAA content of milk accounted for ~90% of its anti-obesity activity. Moreover, diets with native or supplemented BCAA attenuated muscle loss. These data indicate that Ca is responsible for ~40% of the anti-obesity effect of milk while BCAA and ACEi are responsible for much of the additional activity. The results of this study have significance for dieters wishing to achieve optimal body composition. Dairy components are seen here to help with fat loss and lean maintenance during calorie restriction, which may then further aid maintenance of weight loss.
| Identifer | oai:union.ndltd.org:UTENN/oai:trace.tennessee.edu:utk_gradthes-1322 |
| Date | 01 May 2007 |
| Creators | Herweyer, Anna C. |
| Publisher | Trace: Tennessee Research and Creative Exchange |
| Source Sets | University of Tennessee Libraries |
| Detected Language | English |
| Type | text |
| Source | Masters Theses |
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