 In the reality game show The Biggest Loser, contestants compete for cash prizes based on who can lose the most weight. But how should we define “the most weight,” and is The Biggest Loser scored fairly?

In this lesson, students model weight loss with linear equations, and use percent change to compare absolute and relative weight loss for several contestants. They also examine historical data to determine which method produces the fairer game.

Students will

• Write linear functions that model contestants’ weight loss over time
• Calculate weight loss for contestants, both in pounds and as a percent of total weight
• Predict future weight loss using linear models, then compare actual weight loss to predictions
• Interpret scatterplots to determine relationships between contestants’ weight loss and starting weight
• Discuss the downsides of rapid weight loss, and whether or not the weight loss on The Biggest Loser is healthy

Before you begin

Students should be able to write the equation of a line given two points. They should also know how to calculate a percent change based on a starting value (in this case, a percent decrease). They will also need to interpret scatterplots in Act Two, but this lesson could very well serve as an introduction if students are new to scatterplots.

Note: Approximately 1 in 3 American children is overweight or obese, while many others struggle with eating disorders. Before beginning the lesson, you might remind students that this is a sensitive topic for many people, and that you expect their behavior to demonstrate understanding and empathy.