The Effect of Macronutrients in the Diet on Digestive and Cardiovascular Health

Not Applicable

Completed

• Conditions: Obesity; Diabetes; Cardiovascular Diseases
• Interventions: Dietary Supplement: Olive oil and macadamia oil; Dietary Supplement: Olive oil; Dietary Supplement: Olive oil and fish powder; Dietary Supplement: Deadaptation

• Registration Number: NCT01510223
• Lead Sponsor: University of Limerick

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.

Study Timeline

• Study Start: 2010-08
• Primary Completion: 2011-05
• Study Completion: 2011-07
• Status Verified: 2012-01
• Study First Submitted: 2012-01-05
• Study First Submitted QC: 2012-01-10
• Last Update Submitted: 2012-01-10
• Study First Posted: 2012-01-16
• Last Update Posted: 2012-01-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Dietary supplementation macademia oil	Olive oil and macadamia oil	emia oil
Dietary supplementation macademia oil	Deadaptation	emia oil
Dietary supplementation olive oil	Olive oil	Olive oil
Dietary supplementation olive oil	Deadaptation	Olive oil
Dietary Supplementation fish oil	Olive oil and fish powder	fish oil
Dietary Supplementation fish oil	Deadaptation	fish oil

Primary Outcome Measures

Name	Time	Method
Gastric emptying by 13C octanoic acid breath test	within the first 6.5 hours after ingesting high-fat test meal	13CO2 breath samples were taken every 15 minutes for six hours. Breath samples for measurement of 13CO2 were analyzed using isotope ratio mass spectrometry and results were expressed relative to Vienna-PeeDee Belemnite. 13CO2 values were expressed as the excess amount in the breath above baseline and converted into moles. This was then fitted to a GE model developed by Ghoos et al. 1993. For all the data, r2 coefficient between the modeled and raw data was calculated and r2 \> 0.95. Latency phase (Tlat) and ascension time (Tasc) from Schommartz et al. 1998.

Secondary Outcome Measures

Name	Time	Method
Appetite	Within the first 6.5 hours after a meal	Satiety was measured using a 150mm VAS to detect changes in hunger, thirst, desire to eat, tiredness, fullness and cold. Variables thirst, tiredness and cold were used to distract volunteers from analysis of their satiety status. This was taken before breakfast, after breakfast, every 30 minutes throughout the six hours and following the buffet meal.
substrate utilization	Within the first 6.5 hours after a meal	The Douglas Bag technique was employed to collect expired air samples. VO2 and VCO2 were used to calculate substarte oxidation by satndard indirect calorimetry methods.
Food intake by buffet meal	Within 6.5 hours after a meal	After six hours volunteers were given access to a buffet meal and instructed to eat ad libitum. The buffet meal consisted of a 21 different types of foods and contained a wide variety of foods of varying macronutrient. Foods were covertly weighed before and after presentation and the difference converted to macronutrient intake using food tables or manufacturers' data.

Trial Locations

Locations (1)

University of Limerick; 🇮🇪 Limerick, Ireland