Clinical trial NCT01510223: The Effect of Macronutrients in the Diet on Digestive and Cardiovascular Health
Official title: Effect of a 5-day Adaptation and Deadaptation Periods to a High-fat Diet Supplemented With Specific Fatty Acids on Gastrointestinal Transit, Appetite and Substrate Utilisation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Diabetes
Cardiovascular Diseases
Keywords: Fats
Macronutrients
appetite
gastric emptying
Gastrointestinal transit
Lead sponsor: University of Limerick
Sponsor class: OTHER
First posted: 2012-01-16
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: This study examined the effect of a 5-day HFD supplemented with specific fatty acids on gastrointestinal transit, appetite, food intake and substrate utilization. Another novel aspect of this chapter was examining whether a subsequent 5-day period was sufficient to reverse the effects of high-fat feeding on the aforementioned parameters.

Detailed description: High-fat (HF) diets of as little as three days have been shown to accelerate GI transit. This study aimed to assess if 5-day HF supplemented diet varying in fatty acid composition were sufficient to accelerate GI transit, appetite responses and substrate utilisation and whether a 5-day deadaptation period to a HF diet would reverse the responses induced by adaptation to a HFD.

The study will be conducted in a randomized, single-blinded manner in 24 healthy subjects. Three 5-day interventions will each followed by a test trial. In the first intervention period (CON), normal diet was supplemented with low-fat (LF) milkshakes (272 kcal, 6 g fat). The second and third interventions will involve repeating previous diet along with HF (1082 kcal, 96 g fat) or LF milkshakes respectively. The three high-fat supplement groups that subjects will be randomized to are as follows: (1) olive oil (90 g oil), (2) olive oil + n-3 EPA/DHA fish powder blend or (3) olive oil + macadamia oil blend.

The effect of 5-day HF diet (daily milkshake supplement: 1082 kcal, 96 g fat) on gastric emptying and mouth to caecum transit time of a high-fat test will be measured using the 13C octanoic acid breath test and H2 inulin breath test respectively for six hours postprandially. During this time course, measurements of subjective appetite sensations by visual analogue scale and substrate utilization by indirect calorimetry were also collected. Subsequently, food intake will be measured using an ad libitum buffet meal.

Eligibility criteria: Inclusion Criteria:

* Healthy adults aged 18-35 years

Exclusion Criteria:

* History of gastrointestinal-related conditions or gastrointestinal disturbance within 3 months of study entry
* diabetes mellitus
* cardiovascular disease
* Allergies to foods in study
* Pregnancy

Primary outcomes:
measure: Gastric emptying by 13C octanoic acid breath test
timeFrame: within the first 6.5 hours after ingesting high-fat test meal
Secondary outcomes:
measure: Appetite
timeFrame: Within the first 6.5 hours after a meal
measure: substrate utilization
timeFrame: Within the first 6.5 hours after a meal
measure: Food intake by buffet meal
timeFrame: Within 6.5 hours after a meal
Other outcomes:
Locations:
city: Limerick
country: Ireland
facility: University of Limerick
Study officials:
affiliation: University of Limerick
name: Amir Shafat, PhD
role: STUDY_DIRECTOR
affiliation: University of Limerick
name: Oonagh Markey, BSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: Schommartz B, Ziegler D, Schadewaldt P. Significance of diagnostic parameters in [13C]octanoic acid gastric emptying breath tests. Isotopes Environ Health Stud. 1998;34(1-2):135-43.
citation: Ghoos YF, Maes BD, Geypens BJ, Mys G, Hiele MI, Rutgeerts PJ, Vantrappen G. Measurement of gastric emptying rate of solids by means of a carbon-labeled octanoic acid breath test. Gastroenterology. 1993 Jun;104(6):1640-7. doi: 10.1016/0016-5085(93)90640-x.