Effects of Low Fat Versus Low Carbohydrate Diets on Energy Metabolism

Not Applicable

Completed

Conditions: Healthy
Healthy Volunteers

Interventions: Dietary Supplement: LCHF diet
Dietary Supplement: LFHC diet

Registration Number: NCT03878108

Lead Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Brief Summary: Background:

Researchers want to learn how different diets affect hormone levels, body weight, energy expenditure, liver fat, and more. To do this, they will use specialized techniques and food plans. This is not a weight loss study.

Objective:

To better understand how low-fat and low-carbohydrate foods affect health.

Eligibility:

Men and women ages 18-50 who have a stable body weight and can exercise daily

Design:

Participants will have a screening visit that lasts 4-6 hours. It will include:

Medical history

Physical exam

Fasting blood and urine tests

Questionnaires

Trying foods from the study

Participants will be admitted to the Clinical Center and will stay for 4 weeks without leaving. They can have visitors.

Participants will wear activity and glucose monitors throughout the study. They will be weighed daily and will complete daily exercise. They will eat 3 meals daily, plus snacks. They will give urine, saliva, and blood samples. They will fill out questionnaires and rate their hunger, appetite, and sense of taste. They will have body scans. For the scans, they will lie in a machine that takes X-ray pictures of the body.

Participants will complete activities to measure how many calories they burn and how the diets affect them:

Participants will drink special liquids to measure calories burned, sugar, and sense of taste.

Participants will wear a plastic hood while resting.

Participants will stay alone in a special room for 24 hours.

Participants will eat a low-carb, high-fat diet for 2 weeks and a high-carb, low-fat diet for 2 weeks.

Participants may be dismissed if they purposefully use the study to try to change their body weight.

Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases

...

Detailed Description: Competing theories about obesity and its treatment contrast the relative roles of dietary fat versus carbohydrate on promotion of excessive calorie intake. Advocates of low-carbohydrate diets propose that diets high in carbohydrates lead to elevated insulin secretion and increased calorie intake. Alternatively, proponents of low-fat diets argue that diets high in fat promote passive overconsumption due to the high energy density and low satiety index of high-fat foods. Therefore, we will conduct a feeding study in 20 adult men and women to investigate the differences in ad libitum energy intake resulting from consuming two test diets for a pair of 2-week periods in a randomized, crossover design during a single 4-week inpatient period. The test diets presented to participants will be matched for calories and protein, but the low-carbohydrate diet (approximately10% of calories) will be high in fat (approximately75% of calories) whereas the low-fat diet will be high in carbohydrates (approximately75% of calories) and low in fat (approximately 10% of calories).

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 21

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
LCHF diet then LFHC diet	LCHF diet	Low carbohydrate, high fat (LCHF) diet then low fat, high carbohydrate diet (LFHC) diet
LFHC diet then LCHF diet	LCHF diet	Low fat, high carbohydrate diet (LFHC) diet then low carbohydrate, high fat (LCHF) diet
LCHF diet then LFHC diet	LFHC diet	Low carbohydrate, high fat (LCHF) diet then low fat, high carbohydrate diet (LFHC) diet
LFHC diet then LCHF diet	LFHC diet	Low fat, high carbohydrate diet (LFHC) diet then low carbohydrate, high fat (LCHF) diet

Primary Outcome Measures

Name	Time	Method
Ad Libitum Energy Intake	14 days	Ad libitum energy intake averaged over 14 days for each diet, measured in kilocalories (kcal) per day.

Secondary Outcome Measures

Name	Time	Method
Change in C-peptide	Baseline and day 14	Change in C-peptide from baseline to day 14 for each diet
Mean Glucose During Oral Glucose Tolerance Test (OGTT)	Day 14	An OGTT was performed at the end of each 14 day period and the mean glucose was calculated
Change in Cholesterol	Baseline and day 14	Change in cholesterol from baseline to day 14 for each diet
Change in Body Weight	Baseline and day 14	Change in body weight from baseline to day 14 for each diet, measured in kilograms (kg)
Change in CRP	Baseline and day 14	Change in C-reactive protein (CRP) from baseline to day 14 for each diet
Change in Body Fat Mass	Baseline and day 14	Change in body fat mass from baseline to day 14 for each diet, measured in kilograms (kg). Body fat mass was measured using Dual-energy X-ray absorptiometry (DXA) measurements.
Change in TSH	Baseline and day 14	Change in thyroid stimulating hormone (TSH) from baseline to day 14 for each diet
Change in Triglycerides	Baseline and day 14	Change in triglycerides from baseline to day 14 for each diet