Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04744558 |
| Other study ID # |
484-2 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
September 1, 2019 |
| Est. completion date |
December 15, 2019 |
Study information
| Verified date |
February 2021 |
| Source |
University of Belgrade |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The aim of this paper was to investigate and compare the effects of two iso-energetic
hypo-caloric ketogenic hyper-ketonemic and non-ketogenic low carbohydrate high fat high
cholesterol diets on body-composition, muscle strength and hormonal profile in experienced
resistance-trained middle-aged men. Twenty non-competitive experienced resistance-trained
middle-aged men were on the supervised calorie maintenance western diet and
resistance-training regimen for 4 weeks and then divided into ketogenic and non-ketogenic
groups for 8 weeks period. Keto bodies (β-hydroxybutyrate) levels were measured weekly,
testosterone and insulin biweekly, strength and body-composition monthly, lipid profile and
blood sugar level at the beginning and at the end of the study.
Description:
The primary goal of this research was to investigate and compare the effects of two forms of
hypo-caloric LCHF high cholesterol ketogenic hyper-ketonemic and non-ketogenic diets on
muscle strength and body-composition in the experienced resistance-trained middle-aged
healthy male population, and explore possible advantage of ketogenic state. The secondary
goal was to examine the rate and magnitude of hormonal changes during the 8 weeks dietary
phase and their possible impact on the muscle strength and body-composition. It is
hypothesized that calorie intake is the main variable that influences body-compositional
changes regardless of the ketogenic state in similar LCHF dieting conditions.
Four weeks before the experimental procedure participants undertook a detailed medical
examination and subsequently were familiarized with all testing schedules and new training
facilities in which they continued supervised training sessions, with equalized exercise
selection and order for every muscle group as well as for volume and intensity. Participants
were instructed not to change any of their current eating habits supervised for the total
energy intake set at the calorie maintenance requirement, until the beginning of the LCHF
dietary phase of the experiment. After completing 4 weeks of the familiarization phase, the
subjects were randomized into ketogenic (KG) and non-ketogenic group (NKG). The first group
received LCHF high-cholesterol ketogenic dietary treatment, and the second group received
LCHF high-cholesterol non-ketogenic dietary treatment, with the equally reduced calorie
intake. The experimental dietary phase lasted for 8 weeks without any change in resistance
training.
Blood ketones were monitored weekly, hormonal values every 2 weeks, muscle strength and
body-composition every 4 weeks, and basic blood analysis with lipid profile and blood sugar
level at the beginning and at the end of the dietary phase of the study Twenty healthy
non-competitive experienced resistance-trained middle-aged men (Age = 42.7±1.5 years, Body
height = 181.7±4.6 cm, Body mass (BM) = 88.3±5.8 kg), without any recent medical condition,
were selected for this research. Inclusion criteria were more than 5 years of experience with
resistance-training, and a minimum of 2 years of training continuity prior to the study, with
one repetition maximum (1RM) lower limit for bench press at 100% body weight and for squat at
130% bodyweight. In addition, including criteria pertaining to dietary habits, was that no
major change in nutrition regime (prolonged increase or decrease in calories or a
macronutrient percentage change) was taken in the last 6 months prior to the study. No recent
injuries and no medical treatment were mandatory conditions for participation in the study.
After initial consultations, participants were asked to avoid alcohol and training
stimulants. All participants gave written informed consent for study protocol, approved by
the Ethical committee of the Faculty of Sport and Physical Education (IRB: 484-2).
The training was conducted in the same sports facility, supervised by qualified certified
professionals at the same time of the day, with the beginning between 18 h and 19 h, four
times per week on working days. After initial strength testing 4 weeks prior to the dietary
change, subjects training was equalized by the exercise selection, training volume, and
intensity based on their individual 1RM. Every major muscle group was trained twice per week
with free weights and auxiliary cable exercises in the 6 - 12 repetitions range and 60 - 90
seconds between sets and 2 - 3 minutes between exercises. If any of the subjects missed the
training session it was allowed to complete it on another day of the week. Missing training
completely meant disqualification from the study. All participants were instructed not to
perform any additional physical exercise of any type during the study.
At the beginning of the experimental phase, which followed supervised lead-in calorie
maintenance habitual diet phase, weekly LCHF ketogenic and non-ketogenic meal plans were
given to the participants with the additional individual verbal instructions. All supervision
and guidance were carried through on a weekly base by registered dietitian. Collective
supervised attainment of the food supply for every next week was conducted from the same
supermarket brand in 2 locations. Additional individual consultations, if needed, were
provided for all participants at any time point throughout the study, ensuring compliance to
the diet. Every participant was provided with the calibrated kitchen scale (Profi Cook PC-KW
1061) for the duration of the experiment. LCHF diet consisted mainly of meat (beef and veal,
poultry), fish (salmon, sardines, tuna), butter and coconut oil for cooking, fat cheese,
flaxseed and olive oil for salad dressing and green vegetables. Whole eggs were mandatory on
the daily basis insuring intended adequate cholesterol intake. The NKG group obtained their
additional small amount of carbohydrate intake from brown rice. Protein intake was set to be
equal for both experimental groups with differences in CHO and fat content. Macronutrient
ratios for KG and NKG groups were set to 20 %, 5 %, 75 % vs. 20 %, 15 %, 65 % of protein,
carbohydrates and fat, respectively. Caloric intake for experimental phase was set to cover
basal metabolism and sedentary activities (BMR times 1.2) for every participant using the
Mifflin St Jeor equation providing that energy deficit comes primarily from training
activities. Dietary intake was calculated using the Diet Master Pro 14.4 software.
All participants were monitored weekly to achieve and sustain blood β-hydroxybutyrate (BHB)
level of 1 mmol and above in KG and limit it to 0.1 - 0.2 mmol levels in NKG, throughout the
whole duration of the study. If any of the participants were to cross the marked values of
the BHB levels in either direction, evaluation and correction of CHO intake would have been
immediately carried through, and remeasuring was scheduled before the next training session.
All the biochemical testing, except blood ketone values (BHB), were done on Sunday mornings
after a complete day of rest from the last training session on Friday's. Blood samples were
obtained via venipuncture by trained phlebotomists in the morning at 08 h after 12 hours fast
to avoid diurnal variations. Whole blood was collected, transferred into appropriate tubes
for obtaining serum and plasma, and subsequently centrifuged at 1,500 g for 15 min at 4°C.
Resulting serum and plasma were stored at -80°C until analysis which was done on the Roche
Hitachi Cobas c 311 and c 411 (Roche Diagnostics, Hitachi, Tokyo, Japan) using ECLIA and
Spectrophotometry methods for testing testosterone, insulin, blood lipid levels (Total
cholesterol, High density lipoprotein, Low density lipoprotein, Triglycerides) and blood
glucose levels, while ELISA reader RAYTO RT-2100C (Pioway Medical Lab Equipment, Nanjing,
China) was used for determining free testosterone levels. All hormones were measured in the
same assay in duplicate measurements on the same day to avoid compounded inter-assay
variance. The norm for validity of the measurements was intra-assay variance set to less than
5% for all analyses.
The BHB samples were taken from the finger blood sample, using a Precision Xtra™ meter
(Abbott Diabetes Care, Alameda, CA) and were measured in the late afternoon between 17 h and
18 h, before collective training. This timing was chosen as optimal to avoid possible
misreading due to the morning cortisol and training influence.
Maximal strength was determined via 1RM bench press (BP) and squat (SQ) measurements in
accordance with International Powerlifting Federation rules. After performing general
(stationary bicycle) and specific (sets with 50% and 75% of predicted 1RM) warm up, subjects
had up to 5 attempts to achieve 1RM. Every attempt was accompanied by strong verbal
encouragement. All testing was done at the same time of day in which subjects had their
training sessions after two days of rest from the last training.
Body-composition parameters, lean body mass (LBM) and fat mass (FM) were obtained in the
morning after an overnight fast on empty stomach using an electric scale, bio-impedance
device (In Body 720; Biospace Co., Soul, Korea) using the standardized procedure recommended
by the manufacturer and previous studies. In brief, participants were in a standing position
with hands and feet placed on the electrodes. Testing was done and monitored by qualified
laboratory personnel. Participants were instructed to come without any physical effort prior
to the testing.
All measurements and testing were done in accordance with Helsinki declaration and rules of
the Ethic Committee of the Faculty of Sport and Physical Education.
Basic descriptive statistic (Mean, SD) was performed, following a visual inspection of
boxplots for identifying outliers. Normality test was performed for confirmation of the
normality of the data. T test was used to identify differences between lead in and
experimental diets. Mixed (split plot) ANOVA was used to determine the time, group, and
treatment x time interactions. When a significant F-value was found, post-hoc with Bonferroni
adjustment was used for multiple comparisons. Data were reported as mean ± standard
deviation. The level of significance was set at p < 0.05. The program used for statistical
analysis was SPSS 19 (IBM).
