Willemijn M. Vermeer

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The prevalence of overweight and obesity has increased. A strong environmental factor contributing to the obesity epidemic is food portion size. This review of studies into the effects of portion size on energy intake shows that increased food portion sizes lead to increased energy intake levels. Important mechanisms explaining why larger portions are(More)
Background:Environmental interventions directed at portion size might help consumers to reduce their food intake.Objective:To assess whether offering a smaller hot meal, in addition to the existing size, stimulates people to replace their large meal with a smaller meal.Design:Longitudinal randomized controlled trial assessing the impact of introducing small(More)
BACKGROUND   In a previous study, the effectiveness of introducing a small meal in addition to the existing size and a proportional pricing strategy have been assessed in Dutch worksite cafeterias. To assess the degree of implementation and to inform the design of future interventions, the present study aimed to describe the process evaluation of both(More)
This qualitative study assessed consumers' opinions of food portion sizes and their attitudes toward portion-size interventions located in various point-of-purchase settings targeting overweight and obese people. Eight semi-structured focus group discussions were conducted with 49 participants. Constructs from the diffusion of innovations theory were(More)
CONTEXT Reducing health inequalities is a policy priority in many developed countries. Little is known about effective strategies to reduce inequalities in obesity and its underlying behaviors. The goal of the study was to investigate differential effectiveness of interventions aimed at obesity prevention, the promotion of physical activity or a healthy(More)
OBJECTIVE The present study aimed to predict Tanzanian medical students' Voluntary Counseling and Testing (VCT) participation intention using the Health Belief Model (HBM) as a theoretical framework. Further, differences between respondents who had previously participated in VCT and respondents who had not were assessed. METHODS Cross-sectional data were(More)
OBJECTIVE This study aimed to reach consensus among professional experts on patient information provision and support regarding sexual rehabilitation and vaginal dilator use after radiotherapy (RT) for gynecological cancers. METHODS A 3-round online Delphi study was conducted among 10 radiation oncologists, 10 gynecologic oncologists, and 10 oncology(More)
OBJECTIVE Many women treated for cervical cancer (CC) report sexual complaints and sexual distress. It is important to assess these women's and their partners' sexual healthcare needs. This study aims to (a) investigate the prevalence of psychosexual healthcare needs and help-seeking behaviour among CC survivors, (b) identify the association between(More)
About half of the gynecological cancer (GC) survivors suffer from sexual dysfunctions and report a need for professional psychosexual support. The current study assessed (1) health care professionals’ (HCP) current psychosexual support practices, (2) barriers to providing psychosexual support, and (3) HCP needs for training and assistance. Semistructured(More)
OBJECTIVES Food portion-sizes might be a promising starting point for interventions targeting obesity. The purpose of this qualitative study was to assess how representatives of point-of-purchase settings perceived the feasibility of interventions aimed at portion-size. METHODS Semi-structured interviews were conducted with 22 representatives of various(More)