Eating behaviour - explanations for failure of dieting

Question 1

Keys (weight set point)

Answer 1

• semi-starvation; 50% normal calories
• initially lost weight quickly, eventually reached point where men became irritable, hungry and obsessed with thoughts of food
• shows that men initially lost weight quickly as within their set point, then became irritable when below optimum weight
• evidence that body defends fat stores as once weight went below set point their metabolic rate decreased significantly and they avoided physical activity

Question 2

Herman and Mack (boundary model)

Answer 2

• pre-load/taste test method
• group of dieters and non-dieters, gave either a high or low calorie preload
• measured how much they ate in the taste test
• dieters consumed more in the taste test if they had high calorie preload (what the hell effect)
• non-dieters ate less after high calorie preload as they were full
• all women
• practical application
• lab experiment, lack of ecological validity - real world dieting may have more complicated processes
• demand characteristics?
• variety of approaches; cognitive, biological and social