On the rationality of eating junk food

Rational junk-food consumption is analyzed within an expected lifetime utility maximizing framework in which longevity and productivity rise with health, and health deteriorates with junk-food consumption. As long as the junk food’s relative taste-price differential is positive, the consumer’s rational diet deviates from the physiologically optimal one and generates lower than maximal levels of health and productivity. The stationary junk-food consumption, health and productivity depend on the consumer’s tastes, prices, endurance, appetite and time preferences. Damped, or explosive, cycles of junk-food consumption and health may reflect a repulsive, or addictive, effect of ingredients excessively contained in junk food, respectively. JEL classification: I12, D91