OBESITY and Weight Management: Unique opportunity to ASK the DIOGENES experts
4 May 2009 - 6 May 2009
Austria
Wim Saris, Maastricht University, The Netherlands
Co-ordinator of the Diogenes Project
Obesity: determinants – consequences – management
What is Diogenes adding to our knowledge and the debate? How will its results contribute to containing obesity and its consequences?
Arne Astrup, University of Copenhagen, Denmark
Leader of the Diogenes multicentre, randomised, dietary intervention trial
What is the effect of protein and glycemic index in ad lib diets for prevention of weight regain? Does this large randomised study at 8 different centres tell us whether we should eat more or less protein or pay attention to glycemic index?
Marleen van Baak, Maastricht University, The Netherlands
Supervisor of the Supermarket Model in Maastricht – how much ‘control’ did subjects require to keep them compliant? Can this ‘control’ be replicated in real life?
Thomas Meinert Larsen University of Copenhagen, Denmark
Co-ordinator of the dietary intervention study – what are the recorded differences between the supermarket model and dietary instruction models? Which models used in Diogenes helped participants most?
Thorkild Sørensen Institute of Preventive Medicine, Denmark
What has the epidemiological follow-up studies of Diogenes added to our understanding of weight management?
Monique Raats University of Surrey, UK
What are the psychological factors that lead to successful weight management?
What has the Diogenes project added to our understanding?
The DIOGENES Project – an overview
RTD1: Obesity and macronutrient composition of the diet
Co-ordinator: Professor Arne Astrup, Copenhagen, Denmark
The macronutrient composition of the diet appears to play a role in determining the total energy intake. Proteins have been shown to produce a higher degree of satiety and to have a higher stimulating effect on energy expenditure compared with fat and carbohydrates.
In addition carbohydrates with a low glycemic index (GI) have been suggested to have a higher satiating power than carbohydrates having a high GI. However, so far this evidence, which has led to some widely promoted dietary recommendations, has come only from studies limited in duration, subject numbers and types, and dietary variables.
The core of RTD1 will be a 6-12 months dietary intervention study involving some 350 families (obese/overweight parents and their children) across 8 European centres. All adults will complete an 8-week weight loss phase with a fixed low energy intake. Hereafter the families will be randomised to one of 5 diet groups differing in carbohydrate GI and protein content. The aim of this controlled intervention study is to address the efficacy of these diets in preventing weight (re)gain. The intervention study will also generate information and materials for RTDs 2, 3 and 4, and may test new food concepts from RTD5.
RTD2: Obesity and gene-nutrient interaction
Co-ordinator: Dr. Dominique Langin, Toulouse, France
The model for obesity is a two-step one: an individual’s susceptibility is determined largely by genetics, while the observed outcome is determined by environmental factors (diet, physical activity etc.). Understanding of the genetic elements is still limited. We have not identified the multiple genetic determinants of excess fat mass, and knowledge of the interactions of gene function and nutritional status is scarce.
Diogenes will focus on gene-nutrient interactions associated with changes in body weight. RTD2 will identify and characterise biomarkers of dietary intake with variations in GI and protein content and predictors of weight- and metabolic variations. Three complementary, state-of-the-art approaches will be used:
genetics, transcriptomics and proteomics/peptidomics. Input samples and phenotypic data (weight and metabolic variables) will be drawn from the RTD1 intervention study and RTD3 epidemiology cohorts, and findings validated in the intervention study population.
RTD3: Obesity, genes and diet at the population level
Co-ordinator: Professor Thorkild Sørensen, Copenhagen, Denmark
There is strong evidence that environmental factors in general influence the differences in occurrence of obesity both within and between populations, but we do not have a clear and coherent understanding of those factors. One major reason is that weight gain in any single individual is influenced by multiple, interacting, influences, including socio-economic and psycho-social background, life events and life-style, physical activity and diet. For example, there is no clear-cut evidence from prospective population studies pointing to specific dietary components as major factors in obesity development.
Diogenes’ RTD3 will use epidemiology to study the long-term role of key dietary parameters – carbohydrate GI and protein content – in relation to other behavioural, environmental and genetic factors, in influencing obesity and its co-morbidities in the general population across Europe. The studies will draw their data from pre-existing cohorts, including 145,000 subjects followed for up to 5 years in the EPIC cohorts (see www.iarc.fr/epic/) and two twin cohorts in Finland and Denmark. Data from analyses of these cohorts will link with the studies of the RTDs 1 (macronutrient composition), 2 (genetic factors) and 4 (psycho-social factors).
RTD4: Obesity and consumer attitudes and behaviour
Co-ordinator: Dr. Monique Raats, Guildford, United Kingdom
Availability of foods and dietary advice which can facilitate weight control is no guarantee that individuals will successfully control their weight. The majority of individuals who lose weight by dietary adjustment cannot control or sustain the loss. It is clear that in choosing dietary approaches, consumers are influenced by other major factors: their lifestyles, their psychological, psycho-social and physiological characteristics, and their own behaviour patterns. If weight control strategies through diet, such as change in GI and protein content, are to succeed, they need to be complemented by advances in understanding the roles of these factors. New dietary solutions can then be tailored to fit with the consumer’s attitudes, perceptions and difficulties with effective weight control.
RTD4 will develop a series of psychological/behavioural predictors of weight control or gain, which will be validated in the intervention study (RTD1). These predictors will then be integrated with biomarkers (RTD2) and actual responses to diet composition (RTD1) in a new Obesity Risk and Behaviour Advice Screening Tool (ORBAST). ORBAST is a software-based tool to assist consumers in devising, and their health professionals in prescribing, individual behavioural approaches to weight control that better protect against obesity.
RTD5: Obesity and food technology
Coordinator: Dr Øydis Ueland, Oslo, Norway
The sensory experiences of eating determine to a great extent both the foods we choose and how much we eat of them. Diogenes will explore the potential to develop foods that combine liking with limitation of intake due to enhanced satiation signals. RTD5 will bring together
• sensory, metabolic and psychological studies to identify physiological, oral or olfactory triggers which regulate food intake behaviour
• development and testing, including in the dietary intervention study of RTD1, of concept foods which incorporate triggers to regulate intake, as well as varying values for GI and protein content.
Findings on variations in the sensory status of consumers in relation to food intake control will be an additional input to the ORBAST of RTD4.
Co-ordinator of the Diogenes Project
Obesity: determinants – consequences – management
What is Diogenes adding to our knowledge and the debate? How will its results contribute to containing obesity and its consequences?
Arne Astrup, University of Copenhagen, Denmark
Leader of the Diogenes multicentre, randomised, dietary intervention trial
What is the effect of protein and glycemic index in ad lib diets for prevention of weight regain? Does this large randomised study at 8 different centres tell us whether we should eat more or less protein or pay attention to glycemic index?
Marleen van Baak, Maastricht University, The Netherlands
Supervisor of the Supermarket Model in Maastricht – how much ‘control’ did subjects require to keep them compliant? Can this ‘control’ be replicated in real life?
Thomas Meinert Larsen University of Copenhagen, Denmark
Co-ordinator of the dietary intervention study – what are the recorded differences between the supermarket model and dietary instruction models? Which models used in Diogenes helped participants most?
Thorkild Sørensen Institute of Preventive Medicine, Denmark
What has the epidemiological follow-up studies of Diogenes added to our understanding of weight management?
Monique Raats University of Surrey, UK
What are the psychological factors that lead to successful weight management?
What has the Diogenes project added to our understanding?
The DIOGENES Project – an overview
RTD1: Obesity and macronutrient composition of the diet
Co-ordinator: Professor Arne Astrup, Copenhagen, Denmark
The macronutrient composition of the diet appears to play a role in determining the total energy intake. Proteins have been shown to produce a higher degree of satiety and to have a higher stimulating effect on energy expenditure compared with fat and carbohydrates.
In addition carbohydrates with a low glycemic index (GI) have been suggested to have a higher satiating power than carbohydrates having a high GI. However, so far this evidence, which has led to some widely promoted dietary recommendations, has come only from studies limited in duration, subject numbers and types, and dietary variables.
The core of RTD1 will be a 6-12 months dietary intervention study involving some 350 families (obese/overweight parents and their children) across 8 European centres. All adults will complete an 8-week weight loss phase with a fixed low energy intake. Hereafter the families will be randomised to one of 5 diet groups differing in carbohydrate GI and protein content. The aim of this controlled intervention study is to address the efficacy of these diets in preventing weight (re)gain. The intervention study will also generate information and materials for RTDs 2, 3 and 4, and may test new food concepts from RTD5.
RTD2: Obesity and gene-nutrient interaction
Co-ordinator: Dr. Dominique Langin, Toulouse, France
The model for obesity is a two-step one: an individual’s susceptibility is determined largely by genetics, while the observed outcome is determined by environmental factors (diet, physical activity etc.). Understanding of the genetic elements is still limited. We have not identified the multiple genetic determinants of excess fat mass, and knowledge of the interactions of gene function and nutritional status is scarce.
Diogenes will focus on gene-nutrient interactions associated with changes in body weight. RTD2 will identify and characterise biomarkers of dietary intake with variations in GI and protein content and predictors of weight- and metabolic variations. Three complementary, state-of-the-art approaches will be used:
genetics, transcriptomics and proteomics/peptidomics. Input samples and phenotypic data (weight and metabolic variables) will be drawn from the RTD1 intervention study and RTD3 epidemiology cohorts, and findings validated in the intervention study population.
RTD3: Obesity, genes and diet at the population level
Co-ordinator: Professor Thorkild Sørensen, Copenhagen, Denmark
There is strong evidence that environmental factors in general influence the differences in occurrence of obesity both within and between populations, but we do not have a clear and coherent understanding of those factors. One major reason is that weight gain in any single individual is influenced by multiple, interacting, influences, including socio-economic and psycho-social background, life events and life-style, physical activity and diet. For example, there is no clear-cut evidence from prospective population studies pointing to specific dietary components as major factors in obesity development.
Diogenes’ RTD3 will use epidemiology to study the long-term role of key dietary parameters – carbohydrate GI and protein content – in relation to other behavioural, environmental and genetic factors, in influencing obesity and its co-morbidities in the general population across Europe. The studies will draw their data from pre-existing cohorts, including 145,000 subjects followed for up to 5 years in the EPIC cohorts (see www.iarc.fr/epic/) and two twin cohorts in Finland and Denmark. Data from analyses of these cohorts will link with the studies of the RTDs 1 (macronutrient composition), 2 (genetic factors) and 4 (psycho-social factors).
RTD4: Obesity and consumer attitudes and behaviour
Co-ordinator: Dr. Monique Raats, Guildford, United Kingdom
Availability of foods and dietary advice which can facilitate weight control is no guarantee that individuals will successfully control their weight. The majority of individuals who lose weight by dietary adjustment cannot control or sustain the loss. It is clear that in choosing dietary approaches, consumers are influenced by other major factors: their lifestyles, their psychological, psycho-social and physiological characteristics, and their own behaviour patterns. If weight control strategies through diet, such as change in GI and protein content, are to succeed, they need to be complemented by advances in understanding the roles of these factors. New dietary solutions can then be tailored to fit with the consumer’s attitudes, perceptions and difficulties with effective weight control.
RTD4 will develop a series of psychological/behavioural predictors of weight control or gain, which will be validated in the intervention study (RTD1). These predictors will then be integrated with biomarkers (RTD2) and actual responses to diet composition (RTD1) in a new Obesity Risk and Behaviour Advice Screening Tool (ORBAST). ORBAST is a software-based tool to assist consumers in devising, and their health professionals in prescribing, individual behavioural approaches to weight control that better protect against obesity.
RTD5: Obesity and food technology
Coordinator: Dr Øydis Ueland, Oslo, Norway
The sensory experiences of eating determine to a great extent both the foods we choose and how much we eat of them. Diogenes will explore the potential to develop foods that combine liking with limitation of intake due to enhanced satiation signals. RTD5 will bring together
• sensory, metabolic and psychological studies to identify physiological, oral or olfactory triggers which regulate food intake behaviour
• development and testing, including in the dietary intervention study of RTD1, of concept foods which incorporate triggers to regulate intake, as well as varying values for GI and protein content.
Findings on variations in the sensory status of consumers in relation to food intake control will be an additional input to the ORBAST of RTD4.