Weight stigma is defined as the negative attitudes and beliefs that are manifested by stereotypes, rejection and prejudice towards individuals because they are overweight. Weight stigmas have a negative impact on the mental health of people with excess weight. They internalize the weight stigmas and therefore blame themselves and feel less worthy. This can cause their physical health to deteriorate and can lead to weight gain. One of the most harmful types of weight-related stigmatization is the interpersonal stigmatization within the direct social environment. The central aim of this research has been to explore solutions to reduce weight-related stigmatization within the direct social environment of people with obesity. To narrow down the scope, the project was focused on stigmatized women who show interest in body positivity and fat acceptance. This thesis refers to these women as ‘fat’ instead of ‘obese’ in order to respect their cultural values. The research was divided into a theoretical background study, a qualitative user research and an explorative study with methods including interviews, quick prototyping and user tests. The insights gained throughout the project come together into an overview of the most stigmatizing beliefs: (1) Fat people eat too much and exercise too little; (2) Becoming fat due to an unhealthy lifestyle is your own fault; (3) Losing weight is a matter of self-discipline; and (4) Slim people are healthier, happier and more successful. According to this research, the stereotypes and prejudices manifested in these stigmatizing beliefs are the result of misunderstandings and lack of knowledge. Therefore, the overview is complemented with facts and myths about weight that unravel the beliefs. Based on this overview, an interactive platform for fat women was designed: Big Fat Nonsense (in Dutch: Dikke Onzin). This platform consists out of a website (www.dikkeonzin.org), a podcast, a discussion template and social media channels. The design is based on the finding that stigmatized women often cope with internalized stigma. They first need to be empowered in order to stand up for themselves. By reading facts and myths about weight, answering the reflective questions on the website and listening to stories via the podcast, they gain the confidence to start a discussion with a stigmatizer in their direct social environment. A discussion template can be downloaded on the website to structure their conversation about stigmatizing beliefs. By answering the questions on the discussion template, the users are forced to set agreements on the desired weight-related communication within their relationship. In order to reach the target group, the design is promoted via social media channels and ambassadors. Finally, the design of Big Fat Nonsense has been evaluated with the target group and their close relationships. The design succeeded to provoke nuanced and in-depth conversations. However, to fully validate the effect of the design, it should be evaluated by measuring the amount of stigmatization before and after usage.