Collis Williams


A consumer survey was undertaken to test the efficacy of Zotrim, a herbal preparation commercially available as an over the counter weight loss aid. 48 subjects completed a 28 day trial of Zotrim, taken in tablet form just prior to main meals. The results showed a self-assessed average weight loss of 2.3 kg (0.6 kg per week). Questionnaire data suggested that subjects ate less at meals and snacked less frequently. The overall findings supported an earlier placebo controlled clinical trial, and provided additional evidence that Zotrim delays gastric emptying and enhances feelings of fullness. Keywords Overweight, weight loss, herbal, Guarana, efficacy

IntroductionA token search of the Internet reveals a large selection of products which claim to facilitate the process of weight loss. Few are accompanied with appropriate scientific evidence. The desperation of many overweight people can make them particularly receptive to ?quick fixes? such as pills, potions and even creams which appear to offer the desired results without the effort of changing one?s diet or lifestyle. As the critical focus on the weight loss industry sharpens, the more reputable companies are attempting to distance themselves from the rest by funding research into the efficacy of their products. Such a case study is described here.Zotrim is a herbal food supplement, available in tablet form and based on pioneering work by Danish physician, Dr Lasse Hessel. It contains active ingredients as extracts of the South American herbs Yerba mat? (leaves of Ilex paraguayensis), Guarana (seeds of Paullinia cupana) and Damiana (leaves of Turnera diffusa var. aphrodisiaca). An earlier clinical trial (Andersen & Fogh, 2001) found that 24 healthy overweight subjects who were given the Zotrim formulation 3 times per day before meals sustained a mean weight loss of 5.1 kg after 45 days. The 23 subjects who were given the placebo showed a mean weight loss of only 0.3 kg. Neither group received dietary advice. A follow-up of 22 subjects in the Zotrim group after an additional 12 months of treatment revealed that the initial weight loss was maintained. Mean weight at the start of the follow-up was 73 kg, while after 12 months, it was 72.5 kg. It is believed that Zotrim helps to reduce energy intake by delaying gastric emptying or by stimulating an early feeling of fullness. Andersen & Fogh (2001) reported the results of a parallel study which used ultrasound to investigate the rate of gastric emptying in 7 volunteers following consumption of Zotrim versus a placebo. Gastric emptying after Zotrim was 53% slower than after the placebo. A further study by Andersen (2002) examined the time to perceived fullness in 20 subjects taking Zotrim versus a lactose placebo 10-15 minutes before meals. Following the Zotrim tablets, average time to fullness was 35 minutes compared with 61 minutes following the placebo: a statistically significant difference.While the average weight loss seen in the clinical trial was convincing, it is acknowledged that subjects were closely monitored by researchers during their experience with Zotrim. One might question whether unmonitored, free-living consumers would demonstrate a similar weight loss while using the product, thus, a study was implemented to test the efficacy of Zotrim in a completely unmonitored environment using a consumer survey. MethodologyA professional consumer research company (Taylor Nelson Sofres) was instructed to monitor members of the public who had agreed to take part in a 28 day study of Zotrim. Participants were recruited by a combination of word of mouth and advertising in a local newspaper (the Bucks Examiner). Each person who contacted the project team was given a screening questionnaire to fill in which included questions on weight, height, dieting history, snacking habits, medication, general health and perceived body fatness. Completed questionnaires (n=91) were examined and subjects who met the inclusion criteria (body mass index > 20, reported fair-to-good health) were posted a free 30 day supply of Zotrim to take at home (n=75). Instructions were provided on how to take Zotrim (two tablets with a glass of water three times a day 15 minutes before main meals) but no dietary advice was offered. A second questionnaire was completed by subjects after 1 week on the trial and probed compliance, fullness and perceived weight loss. At the end of the 28 day period, the subjects completed a third questionnaire which included questions on weight, compliance, alcohol and eating habits. Of the 75 starters, 50 returned both the questionnaires but 2 forms were incomplete, leaving a final sample of 48. The progress of participants was tracked throughout by Taylor Nelson staff, who used follow-up telephone contact to ensure that as many forms as possible were returned.ResultsThe characteristics of the subjects are shown in Table I. Of those currently following a diet (n=9: all women), the most popular regime was Weight Watchers, but other methods included a low fat diet, reducing snacks and cutting out alcohol. Mean BMI was 28.5 and was similar between men and women. The group included 9 subjects (all women) with a BMI between 22 and 24.9. It was decided to include these people, despite their normal BMI, since Zotrim is available for general purchase and could hypothetically be bought and used by normal weight consumers. However, as described in the Methods section, the line was drawn at respondents with an abnormally low BMI.Take in Table ISubjects? views of their habitual diet are explored in Table II. Over half believed they were eating a healthy balanced diet, which is interesting given the dissatisfaction with their weight. The corollary ? if they believed they had a poor diet ? backed this up, since 58% disagreed with the statement. Most subjects (69%) reported snacking between meals, particularly in the afternoon and evening. Favourite snacks were crisps, biscuits, chocolate and fruit. However, subjects were fairly well split on whether or not they ate too much convenience food (36% agreed, 44% disagreed). In a hint as to what may have caused their excess body weight, 63% of subjects admitted to eating too much food overall. Take in Table IITable III gives the mean weight change for subjects in each of the BMI groups. Overall weight loss was 2.3 kg (0.6 kg per week). The average weight loss was similar in the medium and high BMI groups (around 2.5 kg), while the weight loss in the normal BMI group was lower at 1.4 kg. Compliance with the regime was fairly good. After the first week, the majority of subjects (n=45) reported taking Zotrim as directed most or all of the time. Only 3 subjects said they took Zotrim some of the time. After 4 weeks, the number of compliant subjects had decreased to 39, those reporting taking Zotrim some of the time increased to 7, and 3 admitted not following the regime as directed. Take in Table IIIIn Table IV, perceived fullness 1 week after beginning the Zotrim study is shown. 40 subjects (83%) reported feeling fuller than usual after eating. Of these, the majority (75%) believed that they were eating less in response to this. 15 subjects reported feeling full after each meal, while the remaining 24 experienced increased fullness after only one or two meals during the day. Take in Table IVTaking this information further, Table V gives the subjects? perception of how long feelings of fullness persisted. Of those experiencing fullness (n=40), one third reported it lasting for 30-60 minutes while over 50% reported the fullness lasting up to 3 hours. A significant minority (20%) experienced fullness for more than 3 hours. Take in Table VTable VI highlights one of the reasons why Zotrim may have influenced weight loss. When asked to compare snacking habits before and at the end of the trial, 69% of subjects believed that they now snacked less than usual. 10% of subjects reported no change in snacking habits, while 13% said they no longer snacked.Take in Table VIDiscussionWhile it could be argued that self-reporting of dietary habits and weight has the potential for bias, this consumer study nevertheless supports earlier work on the efficacy of Zotrim (Andersen & Fogh, 2001) and a controlled trial on another Guarana-containing preparation (Boozer et al, 2001). In the latter study, 48 overweight subjects were randomised to receive either a herbal supplement, containing Guarana and ma huang, or a placebo for 8 weeks. Mean weight loss in the intervention group (-4.0 kg) was significantly greater than in the placebo group (-0.8 kg). Average body fat loss showed a similar trend (2.1 kg vs. 0.2 kg).The average weight loss in the present study (i.e. 0.6 kg per week) is rather lower than would be expected from a calorie deficit diet but compares favourably with weight losses achieved by exercise interventions (Donnelly et al, 2003) and low fat diets (Pirozzo et al, 2003). It is gratifying that subjects with a higher initial BMI appeared to experience the greatest weight loss. The Zotrim dose taken in this study (6 tablets per day) is less than the maximum recommended dose of 9 tablets per day. Usual advice included in the Zotrim packaging recommends both regular exercise and a low fat diet. Thus, it might be expected that a higher dose of Zotrim combined with regular exercise and a low fat diet could produce a greater weight loss than 0.6 kg/week. This requires to be investigated in the next stage of research.The most likely reason for the weight loss, given the absence of dietary advice in this particular trial, is a reduction in average daily energy intake due to a prolonged feeling of fullness. Nutritional intake was not measured due to the limitations of the study, but subjects reported eating less at meals and snacking less frequently. If true, this would have certainly contributed to a lower energy intake and a steady weight loss. Further work on Zotrim presented at the 3rd Health and Nutrition Conference (Baker & Leeds, 2002), supports this view. Subjects offered snack food while viewing television ate significantly less when given 2 tablets of Zotrim prior to the experiment than when they were given a placebo.It is also likely that the significant caffeine content of Guarana (10% according to ingredient specifications) contributed to a shift towards negative energy balance. Dulloo et al (1989) observed that a 100 mg bolus of caffeine increased resting metabolic rate (RMR) in both lean and post-obese volunteers by 3-4% over 150 min, and improved the defective dietary-induced thermogenesis (DIT) observed in the post-obese subjects. Acheson et al (1980) found a similar rise in DIT when caffeine was combined with a meal, which implies that caffeine-containing products have the potential to increase RMR and aid weight loss. Indeed, some commercially available anti-obesity drugs contain caffeine (Astrup & Lundsgaard, 1998). It is known that the uptake of caffeine from Guarana is the same as for preparations containing free caffeine (Bempong & Houghton, 1992). Thus Guarana should logically have the same impact on RMR as free caffeine, although it is accepted that that direct evidence for this is lacking.This consumer study supports earlier work which found that Zotrim aids weight loss, at least in part, by restricting average energy intake. It also suggests that favourable results can be reproduced without the comfort and control of a closely supervised clinical trial. AcknowledgementsThis study was funded by Natures Remedies Ltd.The guidance of Dr Anthony Leeds, Kings College London, on the screening questionnaire and specific medical issues, is gratefully acknowledged.CHS RuxtonSenior Lecturer, Department of Human & Health Sciences, School of Biosciences, University of Westminster, London W1W 6UWDr Carrie Ruxton is a Dietitian and Registered Public Health Nutritionist. Telephone: 07973 337757. Email: carrieruxton@aol.comReferencesAcheson, K.J., Zahorska-Markiewicz, B., Pittet, P., Anantharaman, K., Jequier, E. (1980) ?Caffeine and coffee: their influence on metabolic rate and substrate utilization in normal weight and obese individuals?, American Journal of Clinical Nutrition, Vol 33, pp. 989-97. Andersen, T. & Fogh, J. (2001) ?Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients?. Journal of Human Nutrition and Dietetics, Vol 14, pp. 243-250.Andersen, T. (2002). ?Early sensation of gastric fullness following a herbal preparation used for weight loss?. Abstract presented to the 3rd Health and Nutrition Conference, London.Astrup A, Lundsgaard C. (1998) ?What do pharmacological approaches to obesity management offer? Linking pharmacological mechanisms of obesity management agents to clinical practice?, Experimental Clinical Endocrinology and Diabetes, Vol 106 (Suppl 2), pp. 29-34. Baker, G. & Leeds, A.R. (2002) ?Energy intake from snacks while viewing television, and the effect on this of a herbal preparation?. Abstract presented to the 3rd Health and Nutrition Conference, London.Bempong, D.K., Houghton, P.J. (1992) ?Dissolution and absorption of caffeine from Guarana?, Journal of Pharmacy and Pharmacology, Vol 44, pp. 769-71. Donnelly, J.E., Hill. J.O., Jacobsen, D.J., Potteiger, J., Sullivan, D.K., Johnson, S.L., Heelan, K., Hise, M., Fennessey, P.V., Sonko, B., Sharp, T., Jakicic, J.M., Blair, S.N., Tran, Z.V., Mayo, M., Gibson, C., Washburn, R.A. (2003) ?Effects of a 16-month randomized controlled exercise trial on body weight and composition in young, overweight men and women: the Midwest Exercise Trial?, Archives of Internal Medicine, Vol 163, pp. 1343-50. Dulloo, A.G., Geissler, C.A., Horton, T., Collins, A., Miller, D.S. (1989) ?Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers?, American Journal of Clinical Nutrition, Vol 49, pp. 44-50.Pirozzo, S., Summerbell, C., Cameron, C., Glasziou, P. (2003) ?Should we recommend low-fat diets for obesity?? Obesity Reviews, Vol 4, pp. 83-90. Further ZOTRIM information available from:COLLIS WILLIAMS Tel: 21 22 41 04, 21 24 48 47