In the Lean and Obese Dietary Inflammation (LODI) study, short-term intake of a high-fat diet (HFD) that is also high in saturated fatty acids will be examined compared to a low-fat diet (LFD) in individuals who are normal body weight (BMI 19.5-24.9) or who have obesity (BMI of 30 - 40 kg/m2). To characterize persons at baseline, this study will examine body composition, and serum glucose, endotoxin, inflammation and intestinal permeability during fasting and in response to a mixed meal. Also, while it is known that long term intake of foods affects the microbiota, it is unclear whether short-term consumption of a HFD will shift towards a pro-inflammatory gut microbiota compared to a low fat intake. This will be tested in a cross-over design (5 days on a HFD, washout, and 5 days on a LFD) with order randomly assigned in older adults (50+ years of age) who have obesity or are normal weight, and will also be examined by estimated visceral adipose tissue level.
In the Lean and Obese Dietary Inflammation (LODI) study, the primary goal is to determine the effect of short-term intake of high dietary fat (5 days) compared to low fat intake (5 days) in a cross-over design in older adults (men and women) with normal body weight or obesity. Inflammation will be examined by measuring serum endotoxin and other markers, as well as the fecal microbiota.