Thermogenic Properties of Zantrex-3

University of Copenhagen23 enrolled

Overview

Background: Zantrex-3® is a popular dietary supplement for weight control, which consists of a combination of yerba mate, guarana, caffeine and damiana. The combination has previously been shown to decrease gastric emptying and its weight controlling effects may be related to increased satiety and thermogenesis. Objective: To investigate the effect of Zantrex-3® on energy expenditure, hemodynamic factors and subjective appetite sensations. Design: Twenty-three men (BMI: 23.9±3.2 kg/m2, mean±SD) participated in a randomized, double-blind, placebo-controlled crossover study. The Zantrex-3® compound contained 365 mg xantines (caffeine and caffeine-like stimulants), yerba mate, guarana and damiana. The thermogenic effect was measured for 3 hours post-intake. Blood pressure (BP), heart rate (HR) and appetite ratings were assessed every half hour.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Enrollment

Conditions

Obesity

Interventions

The present study was designed as a 2-arm randomised, placebo-controlled, double-blind crossover study. Each treatment was separated by \>7 d washout period. Both treatments were administered as tablets. The Zantrex-3® compound contained yerba maté, caffeine, guarana, damiana, green tea, kola nut, schizonepeta, piper nigrum, ginseng, maca root, and cocoa nut. The content of xantines (caffeine and caffeine-like stimulants) accounted for 365 mg per serving (2 capsules) or 1095 mg (6 capsules) if given as a daily dose. The placebo supplement contained rice flower and could not be distinguished from the Zantrex-3® compound with regard to colour, taste, smell or ap-pearance.

Eligibility

Sex: MALEMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy, * BMI: 23-30 kg/m2, * Weight stable (within +/- 3 kg) two months prior to study inclusion, * Non-smoking, * Nonathletic (\< 10 h hard physical activity), \*The subjects followed a normal Danish habitual diet with rare use of hot spices Exclusion Criteria: * Change in smoking status, * Daily or frequent use of medication, * Suffering from metabolic diseases, * Suffering from psychiatric diseases, * Suffering from any other clinical condition, which would make the subject unfit to participate in the study, * use of dietary supplements or frequent use of medication * blood pressure above 160/90 mmHg

Outcomes

Primary Outcomes

Acute 3-h changes from baseline in energy expenditure and respiratory quotient (RQ)

Subjects underwent assessments of resting metabolic rate (RMR) and respiratory quotient (RQ) by indirect calorimetry using a ventilated hood system (Oxycon Champion, Mijnhardt B.V, Bunnick, The Nederlands). The respiratory measurements were of 3-h duration; from 10 a.m. to 1 p.m. Two baseline measurements (25 minutes) were performed between 9 a.m - 10 a.m. At 10 a.m the participants ingested one serving of the Zantrex-3® supplement or placebo and 25-minutes respiratory measurements were repeated 6 times over the next 3 hours (post-dose).

Time frame: Measured on 2 seperate test days in a crossover design. Each test day is seperated by >7 days.respiratory measurements were of 3-h duration post dose

Secondary Outcomes

3-h acute change in blood pressure (systolic and diastolic)

Heart rate and blood pressure were measured using a digital blood pressure meter with an automati-cally inflating cuff of appropriate cuff size. The results were given as means of 2 to 3 consecutive measurements

Time frame: Measured on 2 seperate test days in a crossover design. Each test day is seperated by >7 days. Measurements were carried out at baseline and time 30, 60, 90, 120, 150 and 180 minutes

3-h acute change in heart rate

Time frame: Measured on 2 seperate test days in a crossover design. Each test day is seperated by >7 days. Measurements were carried out at baseline and time 30, 60, 90, 120, 150 and 180 minutes

Acute 3-h changes from baseline in subjective appetite sensations using visual analogue scales

Assessment of subjective appetite sensations (visual analogue scales (VAS)) at time 0 (baseline - prior to the test meal) and at time 15, 30, 45, 60, 90, 120, 150, 180 minutes post intake. Measured subjective appetite sensations of hunger, satiety, prospective consumption, fullness, composite appetite score and sensory desires to something sweet, salty, rich in fat, or meat/fish.

Time frame: Measured on 2 seperate test days in a crossover design. Each test day is seperated by >7 days. On each test day appetite sensations are measured prior to the test compound (time 0) and 30, 60, 90, 120, 150, 180 minutes post intake

Acute 3-h changes from baseline in self-reported discomfort

The subjects were asked about physiological discomfort trought out the test days.

Time frame: Measured on 2 seperate test days in a crossover design. Each test day is seperated by >7 days. On each test day the subjects were asked if they felt any physiological discomfort after ingesting the test compound