Clinical trial NCT03338452: Low Energy Ketogenic Diet in Obese Subjects - the Impact on Whole Organism
Official title: The Safety and Effects on Whole Organism of Low Energy Ketogenic Diet for Weight Loss in Obese Subjects
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: ketogenic diet
body composition
metabolism
body dissatisfaction
cognition
Lead sponsor: University of Primorska
Sponsor class: OTHER
First posted: 2017-11-09
Enrollment: 38
Sex: ALL
Minimum age (years): 25
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Longitudinal intervention study with repeated measurements. Participants will be subjected to a 12-week low energy ketogenic diet (LEKD) and requested not to change their physical activity levels throughout the study.

The participants will underwent a series of tests and consultations at baseline (prior to the start of the intervention), and after 1, 2, 4, 8 , and 12 weeks of LEKD intervention. At the end of each time points, body weight and composition will be measured in the fasting state, food and exercise diaries checked by a dietitian and a kinesiologist and discussed with the participants, psychological and cognitive tests will be performed by a psychologist. At the same time-points, different serum analyses will be performed.
Primary purpose: TREATMENT

Brief summary: The study evaluates the timeline of changes of body composition, physical and psychological performance, and biochemical markers of metabolism and inflammation responses to low energy ketogenic diet for loosing weight in obese individuals. The participants will be monitored and guided by the interdisciplinary obesity team for 12 weeks.

Detailed description: Ketogenic diets have been shown to be an effective tool to fight obesity with reported good adherence due to their ability to suppress the drive to eat. They are also gaining popularity in public, despite some concerns regarding the quality and timeline of changes of body composition and the effects on health parameters of whole organism.

For effective weight loss, energy deficit is required. Very low energy (600 - 800 kcal) ketogenic diets have been extensively studied.

The proposed study combines low energy (800 - 1500 kcal) and ketogenic diet intervention. The aim of the study is a comprehensive determination of quality of body mass loss, metabolic states changes, physical and psychological performance changes, and inflammatory and hormones profile changes during and post a 12-week low energy ketogenic diet intervention.

Eligibility criteria: Inclusion Criteria:

* BMI \> 30 kg/m2
* asymptomatic for any disease except obesity

Exclusion Criteria:

* presence of cardiovascular, endocrine, acute or chronic inflammatory diseases;
* taking medications for lipid metabolism, or psychiatric disorders;
* adherence to a prescribed diet;
* unstable weight in the past 3 months;
* BMI \< 30 kg/m2;
* unwilling or unable to eat the foods prescribed in the study;
* vigorous physical activity;
* pregnancy or lactation.

Primary outcomes:
measure: Change in body composition
timeFrame: Change from baseline over 12 weeks with intermediate time points at 1, 2, 4 and 8 weeks.
measure: Change in beta-hydroxybutirate
timeFrame: Change from baseline over 12 weeks with intermediate time points at 1, 2, 4 and 8 weeks.
measure: Change in resting energy rate
timeFrame: Change from baseline to 12 weeks.
measure: Change in physical fitness
timeFrame: Change from baseline to 12 weeks.
measure: Change in cognitive functions
timeFrame: Change from baseline to 12 weeks.
measure: Change in psychological factors
timeFrame: Change from baseline to 12 weeks.
Secondary outcomes:
measure: Change in body weight following intervention
timeFrame: Change from 12 weeks to 12 months.
measure: Adherence to ketogenic diet
timeFrame: At 12 months.
Other outcomes:
Locations:
city: Izola
country: Slovenia
facility: University of Primorska, Faculty of Health Sciences
Study officials:
affiliation: University of Primorska, Faculty of Health Sciences
name: Zala Jenko Pražnikar, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Noakes TD, Windt J. Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review. Br J Sports Med. 2017 Jan;51(2):133-139. doi: 10.1136/bjsports-2016-096491.
citation: Yang MU, Van Itallie TB. Composition of weight lost during short-term weight reduction. Metabolic responses of obese subjects to starvation and low-calorie ketogenic and nonketogenic diets. J Clin Invest. 1976 Sep;58(3):722-30. doi: 10.1172/JCI108519.
citation: Urbain P, Strom L, Morawski L, Wehrle A, Deibert P, Bertz H. Impact of a 6-week non-energy-restricted ketogenic diet on physical fitness, body composition and biochemical parameters in healthy adults. Nutr Metab (Lond). 2017 Feb 20;14:17. doi: 10.1186/s12986-017-0175-5. eCollection 2017.
citation: Paoli A, Bianco A, Damiani E, Bosco G. Ketogenic diet in neuromuscular and neurodegenerative diseases. Biomed Res Int. 2014;2014:474296. doi: 10.1155/2014/474296. Epub 2014 Jul 3.