Lean and Obese: Dietary Inflammation (LODI)

Dietary Inflammation in Older Adults: the Role of Obesity

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.

Study Overview

• Status: Completed
• Conditions: Inflammation; Obesity; Dietary Fat
• Intervention / Treatment: Other: Low Fat Diet (LFD); Other: High Fat Diet (HFD)

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New Jersey
    • New Brunswick, New Jersey, United States, 08901
      • Rutgers University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men or Women
• Age 50-79 years (only postmenopausal women > 2 years)
• Body mass index (20-25 kg/m2; and 30-40 kg/m2)*

Exclusion Criteria:

• Diagnosed with, active, or history of liver cirrhosis, chronic or persisting hepatitis
• Diagnosed with, active, or history of cancer
• History of gastrointestinal disease or surgical procedure for weight loss.
• Diagnosed with immune diseases, type 2 diabetes, pancreatitis, or infectious diseases
• Any surgery in the past 6 months
• Currently using or have used antibiotics continuously > 3 days in the past 3 months
• Regular use of medications for that affect the gastrointestinal tract, cholecystitis, urinary tract infection, severe organic diseases including coronary heart disease, myocardial infarction, infectious diseases including pulmonary tuberculosis and AIDS
• Known allergy or intolerance to any ingredients in the dietary intervention program
• Alcohol or illicit drug abuse
• Current Smoker or have quit smoking in the past 3 months
• Recent colonoscopy (within the previous two months)
• Inability to follow any of the experimental diets (including low or high fat diet) or to perform the collections required for this study
• Participants will also be excluded if they have extreme dietary habits, extreme levels of physical or athletic activity, or by changes in body weight >5 lbs. during the last 6 months
• Uncontrolled hypertension or uncontrolled hyperlipidemia in abnormal ranges.

• Participation in another clinical research trial that may interfere with the results of this study.

  • As needed, BMI (kg/m2) will be adjusted accordingly for Asian lean and obese definitions

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Obese; BMI in Obesity range	Other: Low Fat Diet (LFD); Subjects will be asked to adhere to a low fat diet (assigned in random order) and be counseled by a dietitian using 5 days of sample menus, monitored online using a shared nutrient analysis program, and supplied with low fat foods to increase compliance; Other Names: low fat diet; Other: High Fat Diet (HFD); Subjects will be asked to adhere to a high fat diet that is rich in SFAs (assigned in random order) and be counseled by a dietitian using sample 5 days of menus, monitored online using a shared nutrient analysis program, and supplied with high fat foods to increase compliance; Other Names: high fat (high SFA) diet
Experimental: Normal weight (lean); Normal body weight	Other: Low Fat Diet (LFD); Subjects will be asked to adhere to a low fat diet (assigned in random order) and be counseled by a dietitian using 5 days of sample menus, monitored online using a shared nutrient analysis program, and supplied with low fat foods to increase compliance; Other Names: low fat diet; Other: High Fat Diet (HFD); Subjects will be asked to adhere to a high fat diet that is rich in SFAs (assigned in random order) and be counseled by a dietitian using sample 5 days of menus, monitored online using a shared nutrient analysis program, and supplied with high fat foods to increase compliance; Other Names: high fat (high SFA) diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Endotoxin from Low to High fat diet	serum and stool	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks
Change in Microbiome composition	stool	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inflammatory markers	Serum IL-6, hsCRP, TNF-alpha, TLR4 (grams/volume)	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks
Lipopolysaccharide binding protein (LBP)	Serum	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks
Toll like receptor-4 and Null 2 stimulation	serum and the HEK cell reporter assay	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks
Endotoxin in response to a meal	Serum inflammatory response to a mixed meal tolerance test (MMT)	Change over 5 hour MMT
Zonulin	Serum	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Glucose in response to a meal	Serum glycemic response to a meal	Change over 5 hour MMT
Change in PINP in response to a meal	Serum bone formation marker	Change over 5 hour MMT
Change in Osteocalcin in response to a meal	Serum bone formation and energy metabolism marker	Change over 5 hour MMT
Change in CTX in response to a meal	Serum bone resorption marker	Change over 5 hour MMT
Body composition in lean and obese weight groups	total tissue, fat-free soft tissue, fat, visceral adiposity	baseline characteristics
Change in Triglycerides in response to a meal	Serum lipid response to a meal (peak and AUC)	Change over 5 hour MMT
Change in insulin in response to a meal	Serum glycemic response to a meal	Change over 5 hour MMT
Inflammatory markers in response to a meal	serum TNF alpha, CRP and IL-6 (grams/volume)	Change over 5 hour MMT
Lipopolysaccharide binding protein (LBP) in response to a meal	serum	Change over 5 hour MMT
Change in diet quality score	Nutrient analysis and HEI (higher score is better)	Change from LFD (5 days) to HFD (5 days) over an average of 6 weeks

Collaborators and Investigators

• Sponsor: Rutgers, The State University of New Jersey
• Investigators: Principal Investigator: Sue Shapses, PhD, Rutgers, The State University

Publications and helpful links

General Publications

• Ogilvie AR, Onishi JC, Schlussel Y, Kumar A, Haggblom MM, Kerkhof LJ, Shapses SA. Short-term high fat diet-induced metabolic endotoxemia in older individuals with obesity: a randomized crossover study. Am J Clin Nutr. 2025 Aug;122(2):601-611. doi: 10.1016/j.ajcnut.2025.06.001. Epub 2025 Jun 4.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2022
• Primary Completion (Actual): January 1, 2023
• Study Completion (Actual): February 11, 2023

Study Registration Dates

• First Submitted: February 28, 2022
• First Submitted That Met QC Criteria: April 7, 2022
• First Posted (Actual): April 14, 2022

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 8, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: older adults; obesity; microbiome; dietary fat; lean individuals
• Additional Relevant MeSH Terms: Pathologic Processes; Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Inflammation; Therapeutics; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet Therapy; Nutrition Therapy; Diet; Diet, High-Fat; Diet, Fat-Restricted
• Other Study ID Numbers: Pro2019002228

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data that underlie the results and after deidentification will be shared upon request for researchers who provide a methodologically sound proposal (and IRB approved).

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No