Reduction of risk for lifestyle diseases: Group diet and physical activity intervention in the workplace.

Michelle Brenda Cumin

Master of Applied Science

Auckland University Of Technology Auckland

June, 2004

Acknowledgements A huge thank you to each of the wonderful men and women who volunteered to participate in this study for their time, bodies, co-operation and feedback. A special thanks to Elaine Rush and Vishnu Chandu who gave of their time and expertise to carry out the hundreds of measurements needed over the period of the study. Thank you to Professor Lynn Ferguson, my cosupervisor for her help and encouragement and to Dr Lindsay Plank for all his help. Thank you too to Stephanie Schulz for her help with the blood samples and the general flow of measuring days and to the phlebotomists from Medlab particularly Linda who did most of the blood tests. Thank you to the BCMRC team, including Manaia Laulu, Minaxi Patel, Naita Puniani, Vishnu Chandu, Amanda Jordan and the many students, both undergraduate and post- graduate who taught me heaps along the way. Thank you to all the administrative staff at AUT including Heather Stonyer, Benneth Gilbert and Annette Tiaiti for their help and advice. Thank you to my husband Mike and children, David and Tracey for letting me study with them. I would like to acknowledge the generous support of the Auckland University of Technology, Science and Engineering Faculty postgraduate student’s contestable research grant and the Zespri International for the supply of the kiwifruit used in this study. Last and most importantly, my thanks and appreciation to my supervisor Associate Professor Elaine Rush PhD for her encouragement, knowledge, help, advice, mentorship, friendship and sharing. Without her this study would never have taken place. " What the teacher is, is more important than what he teaches." Karl Menninger

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Abstract Background Cardiovascular disease is a major cause of death in most Westernised countries.The prevalence of obesity, type 2 diabetes mellitus and cancers is rapidly increasing. Older people with elevated blood lipids, obesity and DNA damage are at high risk of developing these diseases.

There is a plethora of research to support the claim that a healthy diet and increased physical activity can reduce the risk of increased body fatness, diabetes and generally improve health. However most interventions require intensive one to one advice. The aim of this study was to measure the effect of a group approach to advising on changes in lifestyle with particular attention to foods high in fibre. The study spanned a period of 12 weeks with a follow up session at 52 weeks to ascertain sustainability.

The study This study was a 12 week longitudinal intervention study with a follow up after 52 weeks. Measurements of anthropometry (skinfolds, girths, weight and height), blood pressure, body fat by bioimpedance and fasting blood (lipids, glucose and insulin) were made at weeks 0, 3, 6, 9,1 2 and 52. The participants were asked to complete a food frequency questionnaire and a physical activity questionnaire at each of the 6 measuring sessions and to provide an indication of what the goals that they had set and if they had accomplished them after 9,12 and 52 weeks.

Between measurements at weeks 0 and 3 the volunteers were left to follow their usual food and activity pattern. Then as a group they were given a diet and exercise talk and provided with written material and pedometers to increase motivation. After measurement at week 6 they were randomly divided into two groups. The first group (A) were prescribed and provided with kiwifruit at a dose of 100g/30 kg body weight for three weeks while the second group (B) continued with the changes in diet and physical activity. Following measurement at week 9 group A abstained from kiwifruit while Group B added the kiwifruit to their diet and the measurements repeated. After 52 weeks, with only emails as ongoing communication, they were remeasured.

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Results For this multicultural, relatively middle aged group of 53 staff (28 women, 25 men) of mean age 46 years, measurable and statistically significant metabolic gains were made in the lipid profile over 12 weeks. Total cholesterol, LDL cholesterol, triglycerides and the ratio of total cholesterol to HDL all decreased and HDL increased significantly. Total cholesterol decreased from 5.6(±1.1) mean(±SD) mmol/L at baseline to 5.3(±1.1) mmol/L at week 12 (p