Cholesterol Metabolism, Ketone Metabolism
Conditions
Keywords
ketogenic diet, LDL cholesterol, carbohydrate
Brief summary
The purpose of this study is to understand how the reduction in dietary carbohydrates in a very-low carbohydrate ketogenic diet impacts the synthesis of cholesterol, fatty acid, and ketones, and the turnover rate of VLDL and chylomicron particles.
Detailed description
Participants will consume a standard American diet for one week followed by a very-low carbohydrate ketogenic diet (VLCKD, \<50 grams carbohydrate/day) for two weeks. Participants will undergo an oral stable isotope tracer study during each diet to measure de novo synthesis of fatty acid, cholesterol, ketone bodies, and for measurement of apolipoprotein B and triglyceride kinetics.
Interventions
Standard American diet with 50% energy from carbohydrate, 30% from fat, and 20% from protein.
Ketogenic diet with \<50g carbohydrate, 60-75% energy from fat, and 20% from protein
Sponsors
Touro University, California
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Masking description
The nature of the diet does not allow for masking
Eligibility
Sex/Gender
MALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Male * 18-50 years old
Exclusion criteria
* Use of nicotine products * Has dietary restrictions * Lactose intolerance * History of GI disorders, diabetes, liver, kidney, or thyroid disorders * Taking hypolipidemic, anti-diabetic, anti-hypertensive, or anti-depression medication * Screening plasma triglyceride \< 50mg/dl or \>500mg/dl * Screening glucose \> 125mg/dl * Screening total and LDL-Cholesterol over 95th %tile for age and sex * BP \> 160/95 mmHg * Weight loss/gain \> 5% in the previous 3 months (self-reported)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in total cholesterol | Day 3-7 to Day 17-21 | Change in serum total cholesterol between Day 3-7 (average value) to Day 17-21 (average value) |
| Change in low density lipoprotein (LDL) cholesterol | Day 3-7 to Day 17-21 | Change in serum LDL cholesterol between Day 3-7 (average value) to Day 17-21 (average value) |
| Change in high density lipoprotein (HDL) cholesterol | Day 3-7 to Day 17-21 | Change in serum HDL cholesterol between Day 3-7 (average value) to Day 17-21 (average value) |
| Change in apolipoprotein B (apoB) kinetics | Day 3-7 to Day 17-21 | Change in apoB turnover rates in LDL and very low density lipoprotein plasma fractions as measured using 2H2 leucine incorporation into apoB and mathematical modeling |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in triglyceride lipolysis | Day 3 to Day 17 | Measured by the dilution of administered 2-13C glycerol in plasma |
| Change in serum glucose concentration | Day 3 to Day 17 | Change in fasting and postprandial serum glucose levels |
| Change in fractional hepatic de novo lipogenesis | Day 3 to Day 17 | Measured by the detection of incorporated 1-13C sodium acetate into palmitate in triglyceride rich lipoproteins (TRL) |
| Change in serum insulin concentration | Day 3 to Day 17 | Change in fasting and postprandial serum insulin levels |
| Change in serum ketone body concentration | Day 3 to Day 17 | Change in fasting and postprandial ketone body levels |
| Change in serum free fatty acid concentration | Day 3 to Day 17 | Change in fasting and postprandial serum free fatty acid levels |
| Change in fractional cholesterol synthesis | Day 3 to Day 17 | Measured by the detection of incorporated 1-13C sodium acetate into cholesterol in plasma |
| Change in ketone body synthesis | Day 3 to Day 17 | Measured by the detection of incorporated 1-13C sodium acetate into ketone bodies in plasma |
| Change in TRL-triglyceride kinetics | Day 3 to Day 17 | Change in TRL- triglyceride assembly rates as measured using 2-13C glycerol and mathematical modeling |
Countries
United States
Outcome results
None listed