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Eating Himself to Death

Leptin Signaling Gone Wrong


Michèle I. Shuster
Department of Biology
New Mexico State University


This case study was developed for an introductory biology course with the goal of integrating content (specifically, structure/function, signaling pathways, and homeostasis) while reinforcing general critical thinking skills and the scientific method (generating hypotheses, evaluating evidence, and making predictions). The case is suitable for a flipped classroom and there are several videos associated with it. The case revolves around an obese two-and-a-half-year-old boy who won't stop eating. Students become familiar with some basic concepts related to obesity and leptin signaling through the videos that they watch before class. They then use class time to work through the case (delivered as an interactive slide show, including several clicker questions) to determine the genetic basis for this child's obesity and possible therapies to manage his weight. The case could also be adapted and expanded to be used in a physiology course to explore the interaction of various hormones that regulate appetite and metabolic rate or in a cell biology class to explore JAK-STAT signaling.


  • Explain why obesity is a health concern.
  • Explain the role of leptin in control of appetite.
  • Predict how various disruptions in leptin signaling impact weight.
  • Evaluate the impact of a specific mutation on the leptin signaling pathway.
  • Recommend possible therapies in light of specific disruptions in the leptin signaling pathway.
  • Apply steps of the scientific process to analyze a specific instance of obesity in a young child.


leptin; obesity; BMI; satiety; appetite; D100Y; body weight; energy balance; calories; weight loss; diet; JAK–STAT; hormone; signaling

Topical Areas


Educational Level

Undergraduate lower division


PDF, PowerPoint

Type / Methods

Clicker, Directed, Flipped



Subject Headings

Biology (General)  |   Physiology  |  

Date Posted


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The following video(s) are recommended for use in association with this case study.

  • Obesity Epidemic
    This video describes a variety of contributors to the obesity epidemic, including impacts of society, community structure/design, economics, and culture, highlighting the complexity of obesity. The video also points out the physiological underpinning of obesity and strategies for combating obesity that go beyond the level of an individual person. Running time: 7:13 min. Produced by the Centers for Disease Control and Prevention (CDC), 2011.
  • Leptin, Satiety, and the Mouse Who Ate Too Much
    This video is a whiteboard animation created by the case study author describing the role of leptin in long-term weight homeostasis. The video wraps up by challenging students to think of a variety of ways in which leptin signaling can be disrupted, and the impact of that disruption on weight. Running time: 5:43 min. Produced by Michèle Shuster for the National Center for Case Study Teaching in Science, 2016.
  • Carrying Extra Weight
    This brief optional video shows everyday people reacting to being asked to carry 10 or 20 pound sandbags, mimicking the effect of being 10 or 20 pounds overweight. Running time: 0:30 min. Produced by the National Heart Lung and Blood Institute, National Institute of Health (NIH), 2012.