A Comparison of the Metabolic Effects of Fructose, Glucose, High Fructose Corn Syrup and Sucrose at Normal Population Consumed Levels in Adults Aged 20-60 Years Old

The purpose of this study is to investigate the acute and chronic effects of consumption fructose containing sugars and glucose in a real word setting when consumed in a manner and amount typical in the American diet.

Fructose is known to be metabolized differently than the other common monosaccharides. In addition to the well know lipogenic effects, more recent evidence has shown that the acute changes in hormones and metabolic parameters that control appetite and energy regulation when with fructose consumption may promote caloric overconsumption and, in the long-term, weight gain. However, fructose is rarely consumed in isolation, but instead is consumed in combination with other sugars (with glucose in the case of the two most common sources of fructose: high fructose corn syrup (HFCS) and sucrose, or as part of a mixed macronutrient meal. As such, the practical significance of these short-term findings of isolated monosaccharide consumption is limited.

AIM 1: investigate the response to ten weeks of daily consumption of different fructose containing sugars and glucose at typical intake levels on various metabolic parameters and on fat content of the liver and skeletal muscle.

AIM 2: To investigate whether ten weeks of daily consumption changes the acute metabolic response when these sugars are consumed as part as mixed nutrient meals.

Eligibility Criteria:
Inclusion Criteria:

* Body Mass Index (BMI) 21.0 -33.0

Exclusion Criteria:

* More than a 3% change in weight within the 3 months prior to enrollment in the study.
* Currently smoking cigarettes
* Currently taking any prescription medication for less than 3 months.
* Currently taking a prescription medication for weight loss (4 week wash out period required).
* Currently taking any over-the-counter weight loss supplement/s (2 week wash out period required).
* History of thyroid disease, but not taking medication or medication dosage changed one or more times over last 6 months.
* Diagnosed with Type I or Type II diabetes or prediabetes.
* Major surgery within three months of enrollment.
* History of heart problems (e.g. angina, bypass surgery, MI, etc.) within three months prior to enrollment.
* Presence of implanted cardiac defibrillator or pacemaker.
* Uncontrolled hypertension/high blood pressure.
* History of a surgical procedure for weight loss at any time.
* Gastrointestinal disorders including chronic malabsorptive conditions, peptic ulcer disease, Crohn's disease, chronic diarrhea or active gallbladder disease.
* History of inflammatory bowel disease
* History of fatty liver
* History or presence of cancer (except for successfully resected basal cell carcinoma of the skin more than 6 months prior to enrollment).
* History of clinically diagnosed eating disorders including anorexia nervosa, bulimia nervosa or binge eating disorder.
* Women who are pregnant, lactating or trying to become pregnant.
* History of alcohol dependency
* Currently consuming \>14 alcoholic drinks (1 drink = 12 fl oz beer, 4 fl oz wine or 1.5 fl oz liquor) per week and/or unwilling to limit intake to less than 3 drinks per week during study participation.
* Lactose intolerance
* Known allergy to HFCS, sucrose, fructose or glucose.
* Any clinically significant food allergy
* Participation in another clinical trial within 30 days prior to enrollment.