This case study was developed to engage students by making connections between core concepts in chemistry and obesity related factors. The case is in the form of a story between two friends and their underestimation of the calories they consumed in a meal and their overestimation of the efforts needed to maintain a healthy body weight. Concepts taught by the case include use of conversion factors, calculation of percentages and body mass index, and calculations of caloric values of different foods. The case is suitable for use in courses in general, organic, and biological chemistry as well as in undergraduate nutrition courses.