Online social communities are becoming increasingly popular platforms for people to share information, seek emotional support, and maintain accountability for losing weight. Studying the language and discourse in these communities can offer insights on how users benefit from using these applications. This paper presents a preliminary analysis of language and discourse patterns in forum posts by users who lose weight and keep it off versus users with fluctuating weight dynamics. Our results reveal differences about how the types of posts, polarity of sentiments, and semantic cohesion of posts made by users vary along with their weight loss pattern. To our knowledge, this is the first discourse-level analysis of language and weight loss dynamics.