Ketogenic Diet in Healthy Adults With Differing BMI
NCT Number: NCT06515912
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Cardiovascular Diseases
Interventions: OTHER: Ketogenic Diet
Sponsor: Penn State University
Sex: ALL
Age: ADULT
Enrollment: 40
Study Design: Allocation: NON_RANDOMIZED|Intervention Model: PARALLEL|Masking: NONE|Primary Purpose: PREVENTION
Start Date: 2024-09
Completion Date: 2025-12
Locations: Penn State University, University Park, Pennsylvania, 16802, United States

Summary:
The goal of this clinical trial is to examine the effect of the ketogenic diet over four weeks on blood lipid levels and risk factors for heart disease in adults with a healthy BMI compared to adults with a body mass index (BMI) in the range for obesity. The main questions it aims to answer are:

* Does the ketogenic diet cause larger increases in "bad cholesterol" (low density lipoprotein-cholesterol) in adults with a healthy BMI compared to adults with BMI in the range for obesity?
* Does the ketogenic diet cause larger decreases in vascular health in adults with a healthy BMI compared to adults with BMI in the range for obesity?

Participants will:

* Consume all of the study food provided and avoid intake of non-study foods during the 28-day diet period
* Visit the metabolic kitchen daily (Monday-Friday) to pick up meals
* Attend 5 fasting visits at the Clinical Research Center for testing

Primary Outcome Measures: LDL-cholesterol concentration change from baseline, Assessed from fasting blood draw expressed in mg/dL. LDL-cholesterol will be measured directly via enzymatic assay. Change in LDL-cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks
Secondary Outcome Measures: Endothelial function - Flow Mediated Dilation (FMD) change from baseline, Assessed by fasting brachial arterial ultrasound after transient ischemia expressed in percentage (%). Change in FMD will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Triglycerides concentration change from baseline, Assessed from fasting blood draw expressed in mg/dL. Change in triglycerides will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Total cholesterol concentration change from baseline, Assessed from fasting blood draw expressed in mg/dL. Change in total cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|HDL-cholesterol concentration change from baseline, Assessed from fasting blood draw expressed in mg/dL. Change in HDL-cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Concentration of LDL and triglyceride-rich lipoprotein subparticles change from baseline, Measured via Nuclear Magnetic Resonance and expressed in nmol/L. Change in concentration will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Concentration of HDL subparticles change from baseline, Measured via Nuclear Magnetic Resonance and expressed in µmol/L. Change in concentration will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Size of LDL, HDL, and triglyceride-rich lipoprotein particles change from baseline, Measured via Nuclear Magnetic Resonance and expressed in nm. Change in size will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Central systolic and diastolic blood pressure change from baseline, Assessed using a SphymoCor Xcel (Atcor Medical) and expressed in mmHg. Change in blood pressures will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Brachial systolic and diastolic blood pressure change from baseline, Assessed using a SphymoCor Xcel (Atcor Medical) and expressed in mmHg. Change in blood pressures will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Carotid-femoral pulse wave velocity change from baseline, A measure of arterial stiffness - assessed using a SphymoCor Xcel (Atcor Medical) and expressed in meters/second. Change in pulse wave velocity will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Serum Insulin concentration change from baseline, Assessed in a fasting blood draw and expressed in micro IU/mL. Change in insulin will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Plasma glucose concentration change from baseline, Assessed in a fasting blood draw and expressed in mg/dL. Change in glucose will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Homeostatic model assessment for insulin resistance (HOMA-IR) change from baseline, Calculated from insulin and glucose measured from a fasting blood sample. Calculated as (insulin × glucose) / 22.5. Change in HOMA-IR will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Cholesteryl ester transfer protein (CETP) activity change from baseline, Assessed in fasting plasma samples using an enzymatic activity kit. Change in CETP activity will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Lipoprotein lipase (LPL) activity change from baseline, Assessed in fasting plasma samples using an enzymatic activity kit. Change in LPL activity will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Angiopoietin-Like Protein 3 (ANGPTL3) concentration change from baseline, Assessed in fasting plasma samples using an ELISA kit and expressed in ng/mL. Change in ANGPTL3 concentration will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Angiopoietin-Like Protein 4 (ANGPTL4) concentration change from baseline, Assessed in fasting plasma samples using an ELISA kit and expressed in ng/mL. Change in ANGPTL4 concentration will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Angiopoietin-Like Protein 8 (ANGPTL8) concentration change from baseline, Assessed in fasting plasma samples using an ELISA kit and expressed in pg/mL. Change in ANGPTL8 concentration will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Glucagon concentration change from baseline, Assessed from fasting blood draw expressed in pg/mL. Change in glucagon concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Total adiposity change from baseline, Assessed from Dual-energy X-ray absorptiometry as % body mass. Change in total adiposity will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Estimated visceral adipose tissue change from baseline, Assessed from Dual-energy X-ray absorptiometry and calculated by software in grams (g). Change in estimated visceral adipose tissue will be calculated as the end of diet measure minus the baseline measure., 4 weeks|Alanine transaminase (ALT) change from baseline, Assessed from fasting blood draw expressed in U/L. Change in ALT concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks|Aspartate transaminase (AST) change from baseline, Assessed from fasting blood draw expressed in U/L. Change in AST concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values)., 4 weeks
Other Outcome Measures: Composition of the gut microbiota, Measured using 16 s rRNA gene sequencing, Baseline, 4 weeks