Using data mining to predict success in a weight loss trial

Background: Traditional methods for predicting weight loss success use regression approaches, which make the assumption that the relationships between the independent and dependent (or logit of the dependent) variable are linear. The aim of the present study was to investigate the relationship between common demographic and early weight loss variables to predict weight loss success at 12 months without making this assumption. Methods: Data mining methods (decision trees, generalised additive models and multivariate adaptive regression splines), in addition to logistic regression, were employed to predict: (i) weight loss success (defined as ≥5%) at the end of a 12-month dietary intervention using demographic variables [body mass index (BMI), sex and age]; percentage weight loss at 1 month; and (iii) the difference between actual and predicted weight loss using an energy balance model. The methods were compared by assessing model parsimony and the area under the curve (AUC). Results: The decision tree provided the most clinically useful model and had a good accuracy (AUC 0.720 95% confidence interval = 0.600-0.840). Percentage weight loss at 1 month (≥0.75%) was the strongest predictor for successful weight loss. Within those individuals losing ≥0.75%, individuals with a BMI (≥27 kg m-2) were more likely to be successful than those with a BMI between 25 and 27 kg m-2. Conclusions: Data mining methods can provide a more accurate way of assessing relationships when conventional assumptions are not met. In the present study, a decision tree provided the most parsimonious model. Given that early weight loss cannot be predicted before randomisation, incorporating this information into a post randomisation trial design may give better weight loss results

Variation of the omega-3 content of Australian food products

Abstract from the 2008 Annual Scientific Meeting of the Nutrition Society of Australia, 30 November - 3 December 2008, Glenelg, Australia

Translating advice to eat more vegetables into practice: observations from a 12-month weight loss trial

Objectives: This study aimed to identify the main vegetable sources of overweight participants during a 12-month randomised controlled trial for weight loss. Methods: Secondary analysis using data from diet history interviews to determine changes to daily vegetable intake amounts and types throughout the trial at 0, 3 and 12 months. Results: Pre-trial 77% participants consumed frozen vegetables. At baseline (n = 113, 85 F), participants reported 345 ± 170 (56-920) g/day vegetables increasing to 498 ± 180 (146-930) g/day at 3 months and remaining stable at 475 ± 169(170-1053) g/day by 12 months (p = 0.001). At baseline, 32 of 34 different vegetable categories were reported, mainly tomato (69.9 g/day) and, potato (58.2 g/day). After 3 months (n = 109), seven vegetables remained in the top 10 reported (contributing 72%). Tomato remained top ranked to 12 months. Conclusion: Following advice to consume more vegetables, consumption increased above the Australian Dietary recommendation of ~375 g/day. Tomatoes remained a mainstay regardless of the time of year, but choices changed with time. Frozen vegetables may be a feasible option

Progress of food-based dietary guidelines around the globe

Dietary guidelines have been developed worldwide in an effort to assist populations with healthy food choices. The guidelines may be food or nutrient based and are commonly focused on particular health concerns of the country such as overweight and obesity. There is a large degree of variability in the development of dietary guidelines around the world; some countries have opted for one guideline for all, whereas other countries have developed multiple subsets of guidelines related to particular population groups. The provision of dietary guidelines of a country is not regulated though they are a recommended approach that has been suggested by the World Health Organization (WHO) as one of the two international organizations supporting such activities. The WHO, alongside the Food and Agriculture Organization of the United Nations (FAO), acknowledge that it has long been known that particular nutrients are needed to sustain human health and well-being, and work to disseminate nutrient information to countries in an effort to encourage the development of national dietary allowances for these nutrients. Such nutrient allowances may directly form dietary guidelines of a nutrientfocused nature; though stemming from such developments, countries may also work toward practical approaches of how to translate the nutrient information into everyday practice, an approach often seeing the development of food-based dietary guidelines. This chapter provides an overview to some of the existing dietary guidelines available around the globe. Where a country regularly updates its dietary guidelines, a comparison of the most recent sets of guidelines will also be addressed. The focus of the dietary guidelines also varies between countries with some developed directly for the general public and others specifically targeted at health professionals to assist with consistency of education messages utilized within the country. The guidelines reviewed will be those available as the most recent guidelines published in the English language. The guidelines currently undergoing an update have not been included

Eat nuts for better diabetes management

Eating walnuts everyday may help reduce insulin levels in people with type 2 diabetes. Smart Food Centre researchers at the University of Wollongong Professor Linda Tapsell, Kate Dehlsen, Beck Thorne, Jane O\u27Shea and Kiefer Zhang tell you how

Effect of 6 weeks consumption of b-glucan rich oat products on cholesterol levels in mildly hypercholesterolaemic overweight adults

Abstract presented at the Dietitians Association of Australia 16th International Congress of Dietetics, 5-8 September 2012, Sydney Convention & Exhibition Centre, Sydney, Australi

Effect of 6 weeks\u27 consumption of β-glucan-rich oat products on cholesterol levels in mildly hypercholesterolaemic overweight adults

Several regulatory bodies have approved a health claim on the cholesterol-lowering effects of oat β-glucan at levels of 3·0 g/d. The present study aimed to test whether 1·5 g/d β-glucan provided as ready-to-eat oat flakes was as effective in lowering cholesterol as 3·0 g/d from oats porridge. A 6-week randomised controlled trial was conducted in eighty-seven mildly hypercholesterolaemic ( ≥ 5 mmol/l and \u3c 7·5 mmol/l) men and women assigned to one of three diet arms (25 % energy (E%) protein; 45 E% carbohydrate; 30 E% fat, at energy requirements for weight maintenance): (1) minimal β-glucan (control); (2) low-dose oat β-glucan (1·5 g β-glucan; oats low – OL) or (3) higher dose oat β-glucan (3·0 g β-glucan; oats high – OH). Changes in total cholesterol and LDL-cholesterol (LDL-C) from baseline were assessed using a linear mixed model and repeated-measures ANOVA, adjusted for weight change. Total cholesterol reduced significantly in all groups ( − 7·8 (sd 13·8) %, − 7·2 (sd 12·4) % and − 5·5 (sd 9·3) % in the OH, OL and control groups), as did LDL-C ( − 8·4 (sd 18·5) %, − 8·5 (sd 18·5) % and − 5·5 (sd 12·4) % in the OH, OL and control groups), but between-group differences were not significant. In responders only (n 60), β-glucan groups had higher reductions in LDL-C ( − 18·3 (sd 11·1) % and − 18·1 (sd 9·2) % in the OH and OL groups) compared with controls ( − 11·7 (sd 7·9) %; P = 0·044). Intakes of oat β-glucan were as effective at doses of 1·5 g/d compared with 3 g/d when provided in different food formats that delivered similar amounts of soluble β-glucan

Conversion of Australian food composition data from AUSNUT1999 to 2007 in the Clinical Trial Context

An Australian food composition database, AUSNUT1999, does not include long chain omega-3 polyunsaturated fatty acid (LC omega-3 PUFA) data. Measurement of the fatty acid content of diets initially analysed using AUSNUT1999 requires conversion to AUSNUT2007, an updated database inclusive of LC omega-3 PUFA. The aim of this study was to convert clinical trial dietary data from AUSNUT1999 to AUSNUT2007 and measure LC omega-3 PUFA intake. Clinical trial diet history (DH) data was converted from AUSNUT1999 to 2007 using a staged approach. Macronutrient intake from AUSNUT1999 and 2007 were calculated and compared via paired t-tests and Wilcoxon Signed Ranks tests. Mean dietary LC omega-3 PUFA intake and the percentage contribution of food groups to total LC omega-3 PUFA were then calculated. DHs were collected at baseline (n = 118), three months (n = 86), and 12 months (n = 64). The accuracy of the conversion process improved with time, with no significant difference between most macronutrients at 12 months. Mean LC n-3 PUFA intake was 441.87 mg at baseline, 521.07 mg at 3 months, and 442.40 mg at 12 months, and was predominantly provided by fish and seafood, followed by meat products. This study allowed for the measurement of LC omega-3 intake, which was previously impossible using the AUSNUT1999 database

Consumer understanding and responses to the terms \u27wellness\u27 and \u27wellbeing\u27

Wellness and wellbeing are terms that have a long history of use related to health and capacity for individuals and the community within a broad range of disciplines. However understanding how individuals might interpret these terms within nutrition communications has not been clarified. Eight issue-focussed focus semi-qualitative focus groups and seven issue-focussed semi-structured interviews were conducted with a convenient non-probability purposive sample of 31 women. Final thematic analysis found a mixed response to terms ranging from assurance through confusion and distrust depending on the context and the deliverer of the terms