Diabetes mellitus is a public health problem, which has reached pandemic proportions.
The global prevalence of diabetes is expected to increase with 39% between 2000 and
2030, increasing absolute numbers to 366 million people (1).
Diabetes mellitus is a multi-factorial disease, characterized by hyperglycemia,
resulting from a disturbed insulin secretion, insulin action or both. The long-term
effects of diabetes mellitus include increased risk on complications such as foot ulcers,
retinopathy, nephropathy and neuropathy. Even more problematic is the fact that 70-
80% of people with diabetes die of cardiovascular disease (2). From a public health
perspective, diabetes and its complications are relevant for treatment and prevention
due to the related human suffering and disability and the huge socio-economic costs (3,
4) through premature morbidity (5) and mortality (6, 7). Clearly, there would be great
benefits if research could provide evidence for effective prevention measures. The
introduction of this thesis is composed of three main sections. First, the diagnosis and
pathogenesis of type 2 diabetes are discussed, including the impaired glucose tolerance
state (paragraph 1). The second section focuses on the prevention of type 2 diabetes by the use of different lifestyle intervention strategies and includes some aspects of implementation (paragraph 2). In the third section several mechanisms are discussed that may underlie the development of type 2 diabetes and that may be responsible for the lifestyle intervention-induced improvement in metabolic profile (paragraph 3). Finally, an outline is given of the chapters covering the present thesis.

Cheryl Roumen, November 6th 2009