Adverse Metabolic Effects Of Dietary Sugar: Ad Libitum vs Energy-Balanced Diets
- Peter J. Havel, DVM, PhD, Professor, Department of Molecular Biosciences, School of Veterinary Medicine and Department of Nutrition
- Kimber L. Stanhope, RD, PhD, Research Nutritionist, Department of Molecular Biosciences, School of Veterinary Medicine
- Candice A. Price, PhD, Adjunct Assistant Professor, Department of Molecular Biosciences, School of Veterinary Medicine
- Bettina Hieronimus, PhD, Postdoctoral Researcher, Department of Molecular Biosciences, School of Veterinary Medicine
- Desiree Sigala, PhD Candidate, Graduate Group in Nutritional Biology
- Vivien Lee, Staff Research Associate, Department of Molecular Biosciences, School of Veterinary Medicine
- Marinelle Nunez, Staff Research Associate, Department of Nutrition
- James L. Graham, Staff Research Associate, Department of Nutrition
NIH National Heart, Lung Blood Institute (NHLBI)
$853,462 (1 year)
Recent studies have demonstrated that consuming high fructose corn syrup (HFCS)- or sucrose-sweetened beverages increased lipid/lipoprotein risk factors for CVD in healthy adults compared with iso-caloric amounts of glucose or low-fat milk. The longest of these studies, which utilized a 6-month intervention, also showed increased liver and muscle TG and increased visceral adipose deposition. There were no differences in weight gain between subjects consuming sucrose beverages compared with control beverages. These results suggest that it is not just excess calories and weight gain that mediate the effects of dietary sugar/fructose on the development of metabolic disease; rather, dietary sugar per se is also a contributor. However, it is not known whether consumption of excessive amounts of sugar can increase risk factors for metabolic disease in the absence of positive energy balance and weight gain. Also, the contribution of sugar and the contribution of excess energy and weight gain on risk factors and processes associated with metabolic disease have not been compared under standardized dietary conditions. Finally, the effects of consuming sugar-sweetened beverage compared with aspartame (ASP)-sweetened beverages on energy intake and body weight gain has not been investigated under standardized conditions in which the diets are provided and carefully formulated to ensure that the overall macronutrient intake, as well as the fiber intake, is comparable in both groups.
This study seeks to address these gaps in knowledge. We are investigating and comparing the effects of consuming high fructose corn syrup (HFCS)- or ASP-sweetened beverages with both energy-balanced and ad libitum diets on risk factors and processes associated with the development of metabolic disease. We utilizing a controlled 6-week dietary protocol, in which diets formulated to achieve a comparable macronutrient intake (55%Ereq carbohydrate, 35% fat, 15% protein) among all 4 diet groups, will be provided to the subjects for the first 6 weeks of the study. We hypothesize that consumption of HFCS-sweetened beverages with the energy-balanced diet will result in adverse metabolic effects, despite the absence of weight gain. Consumption of HFCS-sweetened beverages with the ad libitum diet will result in increased energy intake and body weight gain compared with aspartame-sweetened beverages, and will also result in adverse metabolic effects that are more marked than with consumption of HFCS-sweetened beverages with the energy-balanced diet. These results will demonstrate that consumption of HFCS-sweetened beverages increases risk for metabolic disease both directly, via the adverse effects of fructose on lipid and carbohydrate metabolism, and indirectly, via the effects of HFCS-sweetened beverages to promote excess energy intake and body weight gain. These findings will have the potential to influence dietary guidelines and public health policy. This project has also been awarded two Diversity Supplements to support Dr. Candice Price and PhD student, Desiree Sigala. Dr. Price has been awarded a scholarship for the Building Interdisciplinary Careers in Women’s Health Program.