Epidemiological evaluation of dietary intake in the Swiss population: dietary intake in Switzerland : Diet in Switzerland: not only chocolate and cheese

Diet is a major component of prevention, management and treatment of most noncommunicable disorders and a key element of maintaining health. Dietary policies are essential for health maintenance and disease prevention and should be implemented based preferably on information collected in the target population. Switzerland has the second highest health expenditure worldwide, but little if no dietary preventive measures are implemented at the population level. Likely reasons are separation of competencies between the different political structures in Switzerland and the difficulty in having standardized instruments to assess dietary intake in a multilingual heterogeneous country. The objective of this thesis was to provide some information to the following issues: a) the dietary intake of the Swiss population; b) the associations between diet and non-communicable diseases, and c) the dietary management of cardiovascular risk factors and cardiovascular disease. In _chapter 2_ of the thesis, we show that dietary patterns have favourably evolved in the population of canton Geneva between 1993 and 2014, while the barriers to healthy eating have decreased in the Swiss population. We then show that compliance to the dietary guidelines of the Swiss Society of Nutrition has slightly improved between 1993 and 2017 in canton Geneva, although compliance to some items such as dairy products and meat failed to improve. We also show that the issuing of dietary guidelines by the Swiss society of nutrition did not impact the compliance rates. The last part of the chapter is dedicated to trends in other dietary related factors such as vitamin, mineral and dietary supplements in canton Vaud, the prevalence of which remained stable (20.6% in 2003-2006 and 20.3% in 2009-2012). In _chapter 3_, we focus on the associations between dietary intake and several markers of noncommunicable diseases. We show that dietary patterns obtained using principal components analysis are associated with obesity, smoking and socio-economic markers. We also show that a dietary pattern rich in fruits and vegetables is negatively related with inflammatory markers. Conversely, dietary intake appears to have little impact on the incidence of hypertension in a middle-aged population. In _chapter 4_, we analyse the dietary management of cardiovascular risk factors such as dyslipidemia and type 2 diabetes and on dietary changes after a CVD event. We show that patients with dyslipidemia have a higher consumption of fruits, vegetables, fish, mono- and polyunsaturated fats than the general population. Conversely, only half of patients with type 2 diabetes report being on an anti-diabetic diet. Diabetic patients consume more artificial sweeteners and less sugary products than the general population and, except for a higher consumption of vegetables, no differences were found between diabetic patients reporting or not an anti-diabetic diet. Finally, we show that patients with a CVD event do not change their dietary intake and lifestyle changes for the secondary and tertiary prevention of cardiovascular disease. Overall, our results show that dietary intake of the Swiss population could be improved, and that dietary management of cardiovascular risk factors among patients could be implemented.