ARS | Publication request: A dairy-based high calcium diet improves glucose homeostasis and reduces further weight gain in high fat fed mice in the context of pre-existing obesity

Submitted to: Nutrition and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 21, 2011
Publication Date: February 22, 2012
Repository URL: http://www.nutritionandmetabolism.com/content/9/1/3
Citation: Thomas, A.P., Dunn, T.N., Drayton, J.B., Oort, P.J., Adams, S.H. 2012. A dairy-based high calcium diet improves glucose homeostasis and reduces further weight gain in high fat fed mice in the context of pre-existing obesity. Nutrition and Metabolism. 10.1186/1743-7075-9-3.

Interpretive Summary: Background: High dietary calcium (Ca) in the context of a dairy food matrix has been shown to reduce obesity development and associated inflammation in diet-induced obese (DIO) mice. However, the influence of Ca and dairy on these phenotypes in the context of pre-existing obesity is not known. Methods: We characterized adiposity along with associated metabolic and inflammatory outcomes in DIO mice previously fattened for 12 wk on a dairy-free, soy protein-based high fat diet (45% energy, 0.5% Ca), then fed one of three high fat diets (n = 30/group) for an additional 8 wk: control (same as lead-in diet), high-Ca (1.5% Ca), or high-Ca + nonfat dry milk (NFDM). Results: Mice fed high-Ca + NFDM had attenuated weight gain compared to both controls and mice fed high-Ca (P < 0.001), whereas mice fed high-Ca without dairy had increased weight gain compared to controls (P < 0.001). However, despite modest differences in body weight, total measured adipose depot weights between groups was similar, as were white adipose tissue inflammatory marker mRNA abundances (e.g., TNFa, IL-6). Mice fed high-Ca + NFDM had improved glucose homeostasis and markedly lower liver triglycerides. Conclusion: Reduced obesity progression and improved metabolic phenotypes in response to increased dietary Ca may require dairy food components, or alternatively these outcomes may be primarily driven by non-Ca factors derived from dairy.

Technical Abstract: Background: High dietary calcium (Ca) in the context of a dairy food matrix has been shown to reduce obesity development and associated inflammation in diet-induced obese (DIO) mice. However, the influence of Ca and dairy on these phenotypes in the context of pre-existing obesity is not known. Methods: We characterized adiposity along with associated metabolic and inflammatory outcomes in DIO mice previously fattened for 12 wk on a dairy-free, soy protein-based high fat diet (45% energy, 0.5% Ca), then fed one of three high fat diets (n = 30/group) for an additional 8 wk: control (same as lead-in diet), high-Ca (1.5% Ca), or high-Ca + nonfat dry milk (NFDM). Results: Mice fed high-Ca + NFDM had attenuated weight gain compared to both controls and mice fed high-Ca (P < 0.001), whereas mice fed high-Ca without dairy had increased weight gain compared to controls (P < 0.001). However, despite modest differences in body weight, total measured adipose depot weights between groups was similar, as were white adipose tissue inflammatory marker mRNA abundances (e.g., TNFa, IL-6). Mice fed high-Ca + NFDM had improved glucose homeostasis and markedly lower liver triglycerides. Conclusion: Reduced obesity progression and improved metabolic phenotypes in response to increased dietary Ca may require dairy food components, or alternatively these outcomes may be primarily driven by non-Ca factors derived from dairy.