Applying Behavioral Economics to Applying Behavioral Economics to Weight-LossWeight-Loss

Why Dieters Fail?Why Dieters Fail?

Shahram HeshmatShahram Heshmat Department of Public Health; University of Illinois at Springfield Department of Public Health; University of Illinois at Springfield

(UIS), Springfield, IL (UIS), Springfield, IL Corresponding author: Tel: 217-206-7878, Corresponding author: Tel: 217-206-7878, Fax: 217-206-7807 Fax: 217-206-7807

E-mail addressE-mail address: : Heshmat.Shahram@uis.eduHeshmat.Shahram@uis.edu

The Second National Predictive Modeling SummitThe Second National Predictive Modeling SummitSeptember 22 – 23, 2008September 22 – 23, 2008

Washington, Washington,

Issues Issues

► The 21st century will be the Century of behavior The 21st century will be the Century of behavior change. Changing everyday, long-term behavior is the change. Changing everyday, long-term behavior is the key to adding years and quality to our lives -Wansink key to adding years and quality to our lives -Wansink (2006)(2006)

► There exist mountains of very good science about what There exist mountains of very good science about what constitutes a healthy lifestyle, but still our leading cause constitutes a healthy lifestyle, but still our leading cause of death is I’ll Do It Starting Tomorrow – people of death is I’ll Do It Starting Tomorrow – people continuing to eat poorly, smoke, not exercise, drink in continuing to eat poorly, smoke, not exercise, drink in excess. - Robert Sapolskyexcess. - Robert Sapolsky

Research QuestionsResearch Questions

►Why is it that people who are able to Why is it that people who are able to successfully initiate changes in their behavior successfully initiate changes in their behavior have difficulty maintaining it over time?have difficulty maintaining it over time?

►How to overcome the problem that individuals How to overcome the problem that individuals are not always able to maximize their own well-are not always able to maximize their own well-being?being?

Purpose Purpose

► To present some insights from behavioral economics to To present some insights from behavioral economics to explain why people fail to maintain healthy behavior. explain why people fail to maintain healthy behavior. This is accomplished by looking at conditions in which This is accomplished by looking at conditions in which the decision making is impaired or even breaks down.the decision making is impaired or even breaks down.

► Knowing why people fail to maintain a desired Knowing why people fail to maintain a desired preference for healthy behavior over time is an essential preference for healthy behavior over time is an essential ingredient in the development of effective weight-loss ingredient in the development of effective weight-loss management. management.

► To draw implications for obesity prevention.To draw implications for obesity prevention.

TrendsTrends

Obesity prevalence: United States, 2005–2006Obesity prevalence: United States, 2005–2006

Obesity across countries: Obesity across countries: Percentage of population aged 15 and over, with a BMI greater 30 (2003). Percentage of population aged 15 and over, with a BMI greater 30 (2003). SourceSource: OECD : OECD

Fact book 2005. Fact book 2005.

Causes of ObesityCauses of Obesity ► Within the past several decades, five developments Within the past several decades, five developments

have tipped the balance between caloric intake and have tipped the balance between caloric intake and expense to an unfavorable equilibrium:expense to an unfavorable equilibrium:

Expanding labor market opportunities for womenExpanding labor market opportunities for women Increased consumption of food away from homeIncreased consumption of food away from home Rising costs of healthy foods relative to unhealthy Rising costs of healthy foods relative to unhealthy

foodsfoods Growing quantity of caloric intake with declining Growing quantity of caloric intake with declining

overall food prices overall food prices Decreased requirements of occupational and Decreased requirements of occupational and

environmental physical activity environmental physical activity

Poverty and obesityPoverty and obesity ► The Engel’s law: consuming energy-dense foods The Engel’s law: consuming energy-dense foods

(e.g., doughnuts, potato chips), and energy-dense (e.g., doughnuts, potato chips), and energy-dense diets, is an important strategy used by low-income diets, is an important strategy used by low-income consumers to stretch the food budget consumers to stretch the food budget

► Energy-dense foods carry a lower price tag, which Energy-dense foods carry a lower price tag, which allows for a higher energy consumption at a lower allows for a higher energy consumption at a lower cost. E.g., a dollar buys 1,200 calories in the form of cost. E.g., a dollar buys 1,200 calories in the form of a package of cookies (Chips Ahoy!), but only 250 a package of cookies (Chips Ahoy!), but only 250 calories in that of a bag of carrots. calories in that of a bag of carrots.

The health risks of obesityThe health risks of obesity

► Overweight and obesity have become to diabetes what Overweight and obesity have become to diabetes what tobacco is to lung cancer. tobacco is to lung cancer.

► Roughly 60% of all cases of diabetes can be directly Roughly 60% of all cases of diabetes can be directly attributed to weight gain. attributed to weight gain.

► Obese adults have about 10 times the risk of developing Obese adults have about 10 times the risk of developing diabetes compared with normal-weight adults. diabetes compared with normal-weight adults.

► The health care costs attributed to overweight is over The health care costs attributed to overweight is over $100 billion per year – or 9.1% of the country’s health $100 billion per year – or 9.1% of the country’s health expenditure. expenditure.

How do we evaluate the rise in body weight, and How do we evaluate the rise in body weight, and the harm to people’s health?the harm to people’s health?

►It is a choice to be fat: the person actually It is a choice to be fat: the person actually prefers eating more and being fat to eating less prefers eating more and being fat to eating less and being thinner.and being thinner.

►He can’t help what he is doing.He can’t help what he is doing.

Standard Model of Economic Choice Standard Model of Economic Choice

► The objective is to maximize utility [U = f (X, W)], The objective is to maximize utility [U = f (X, W)], subject to a money income constraint and a time subject to a money income constraint and a time constraint. constraint.

► We act consistently - A good decision is to choose and We act consistently - A good decision is to choose and pursue an outcome that is liked best when it is gained, pursue an outcome that is liked best when it is gained, from among all available options.from among all available options.

► Revealed preferenceRevealed preference► Opportunity set (e.g., a large number of TV channels Opportunity set (e.g., a large number of TV channels

increase life satisfaction) increase life satisfaction)

The rational choice theory has only two concepts to explain the obesity The rational choice theory has only two concepts to explain the obesity epidemic: 1) overweight individuals have poor health and nutrition epidemic: 1) overweight individuals have poor health and nutrition information, 2) they actually prefers eating more and being fat to eating less information, 2) they actually prefers eating more and being fat to eating less and being thinner. and being thinner.

In the first case, all we can say is that overweight individuals are making In the first case, all we can say is that overweight individuals are making mistake, in the second case, they don’t value their health. mistake, in the second case, they don’t value their health.

► Overweight and happinessOverweight and happiness

Behavioral economics, on the other hand, assumes that people are susceptible Behavioral economics, on the other hand, assumes that people are susceptible to temptations and they tend to pursue immediate gratification in way that to temptations and they tend to pursue immediate gratification in way that they themselves do not appreciate in the long run. they themselves do not appreciate in the long run.

What is behavioral What is behavioral Economics?Economics?

► The field of behavioral economics blends insights of The field of behavioral economics blends insights of psychology and economics. It uses insights from psychology and economics. It uses insights from psychology to develop more “realistic” models of psychology to develop more “realistic” models of individual decision-making, in which people often do individual decision-making, in which people often do things that are not in their best interests. things that are not in their best interests.

► Behavioral economics explains why people appear so Behavioral economics explains why people appear so inconsistent when their behavior is viewed through the inconsistent when their behavior is viewed through the lens of the standard economic model. lens of the standard economic model.

Choice over timeChoice over time

► A key concept in behavioral economics is that of how A key concept in behavioral economics is that of how delayed rewards are discounted by individuals, and delayed rewards are discounted by individuals, and deviation from the rational-choice paradigm.deviation from the rational-choice paradigm.

► Discounting of delayed rewards refers to the Discounting of delayed rewards refers to the observation that the value of a delayed rewards is observation that the value of a delayed rewards is discounted (reduced in value or considered to be discounted (reduced in value or considered to be worth less) compared to the value of an immediate worth less) compared to the value of an immediate rewards. Higher discount rates give greater weight to rewards. Higher discount rates give greater weight to benefits and costs accruing early in the life cycle than benefits and costs accruing early in the life cycle than do lower discount rates. do lower discount rates.

The Seductive Present-MomentThe Seductive Present-Moment

► Insights from behavioral economics indicate that Insights from behavioral economics indicate that people are often of two minds when it comes to people are often of two minds when it comes to intertemporal choice - they are often powerfully intertemporal choice - they are often powerfully motivated to take myopic actions, such as eating motivated to take myopic actions, such as eating highly caloric foods, while recognizing highly caloric foods, while recognizing simultaneously that these activities are not in their simultaneously that these activities are not in their self-interest. self-interest.

► Such preferences imply that people have self-control Such preferences imply that people have self-control problems wherein they are unable on a moment-by-problems wherein they are unable on a moment-by-moment basis to behave in their own long-term best moment basis to behave in their own long-term best interest. interest.

An Example:An Example:

Option A: Starting an exercise program todayOption A: Starting an exercise program today

► CostCostt0t0 = 8, Value = 8, Valuet1t1 = 10 => net gain = 2; net = 10 => net gain = 2; net gain (discounted @ 50%) = -8 +1/2(10) = -3 gain (discounted @ 50%) = -8 +1/2(10) = -3

► So we are reluctant to start exercising So we are reluctant to start exercising today.today. Option B: Starting tomorrow: Option B: Starting tomorrow: ► CostCostt1t1 = 8, Value = 8, Valuet1t1 = 10 => net gain (time = 10 => net gain (time

adjusted) = -8 (1/2) +1/2(10) = 1 adjusted) = -8 (1/2) +1/2(10) = 1 ► Hence, everyone is enthusiastic about going Hence, everyone is enthusiastic about going

to the gym to the gym tomorrow.tomorrow.

Time

Time

Preference Reversal

Preference reversal Preference reversal

► A surge of preference for the A surge of preference for the less valued alternative when less valued alternative when it looms close.it looms close.

► Indulge now and abstain Indulge now and abstain tomorrow: the long-term tomorrow: the long-term motivation is constantly motivation is constantly threatened by short-term threatened by short-term motives motives

► We are strangers to ourselves We are strangers to ourselves

SummarySummary

►In sum, individuals display behavior that is In sum, individuals display behavior that is dynamically inconsistent. Initially people prefer dynamically inconsistent. Initially people prefer X to Y, but they later choose Y over X. How can X to Y, but they later choose Y over X. How can such behavior be understood? What is about the such behavior be understood? What is about the immediacy of an event that blinds us to better immediacy of an event that blinds us to better alternatives that we might have if we could only alternatives that we might have if we could only wait a little for them? wait a little for them?

Self-control problem Self-control problem

The Mechanisms of Preference ReversalThe Mechanisms of Preference Reversal

► The Duplex Mind: Impulsive vs. Reflective The Duplex Mind: Impulsive vs. Reflective Decision-MakingDecision-Making

► Asymmetric warfare between emotion and Asymmetric warfare between emotion and cognitioncognition

► Our emotional brain has a hard time imagining Our emotional brain has a hard time imagining the future, even though our logical brain the future, even though our logical brain clearly sees the future consequences of our clearly sees the future consequences of our current actions.current actions.

Affective and Deliberating Affective and Deliberating ProcessingProcessing

The Primacy of Emotion The Primacy of Emotion

Willpower Willpower

►Willpower is an important ingredient in self-Willpower is an important ingredient in self-control. control.

►Self-control functions like a muscle that can be Self-control functions like a muscle that can be depleted with use but strengthened over time. depleted with use but strengthened over time.

Dieting as a choice over timeDieting as a choice over time

► Dieting is a popular means of weight control. It is estimated that 24% of Dieting is a popular means of weight control. It is estimated that 24% of men and 38% of women in the US are trying to lose weight. men and 38% of women in the US are trying to lose weight.

► The two principal reasons given by dieters for wanting to lose weight: The two principal reasons given by dieters for wanting to lose weight: health and attractiveness health and attractiveness

► Dieting behavior can be viewed as making constant trade-offs between Dieting behavior can be viewed as making constant trade-offs between immediate and delayed benefits under uncertain conditions (“a moment on immediate and delayed benefits under uncertain conditions (“a moment on the lips, a lifetime on the hips,”)the lips, a lifetime on the hips,”)

► This difference in the timing of costs and benefits constitutes one of the This difference in the timing of costs and benefits constitutes one of the major obstacles to dieting. Food brings immediate gratification, while the major obstacles to dieting. Food brings immediate gratification, while the health costs of overconsumption occur only in the future. As every dieters health costs of overconsumption occur only in the future. As every dieters know, it is one thing to plan for meeting caloric restrictions, but quite know, it is one thing to plan for meeting caloric restrictions, but quite another to maintain it. another to maintain it.

Why Dieters Fail?Why Dieters Fail?

Visceral feelings: Hunger, StressVisceral feelings: Hunger, Stress Cue-Elicited Behavior Cue-Elicited Behavior Attentional Bias Attentional Bias Willpower (Ego Depletion)Willpower (Ego Depletion) Hot-cold empathy gap: underestimate the power of Hot-cold empathy gap: underestimate the power of

cravingcraving ““What the hell” effectWhat the hell” effect Alcohol myopiaAlcohol myopia Social InfluenceSocial Influence Awareness of self –control problemAwareness of self –control problem

Explaining Overweight in Modern Explaining Overweight in Modern SocietySociety

Overweight in modern society Overweight in modern society

► The role of stress (e.g., increased demand on women at home and The role of stress (e.g., increased demand on women at home and on the job) on the job)

► Homeostatic vs. Hedonic hunger (wanting)Homeostatic vs. Hedonic hunger (wanting)► Wanting (choice) and Liking (hedonic reaction) are separable Wanting (choice) and Liking (hedonic reaction) are separable

systemssystems► Transient irrational wanting comes and goes with the cues.Transient irrational wanting comes and goes with the cues.► Wanting system seems more sensitive to the widespread Wanting system seems more sensitive to the widespread

availability of highly palatable food, which creates hedonic availability of highly palatable food, which creates hedonic hunger (“perceived deprivation”)hunger (“perceived deprivation”)

► The permissive social norm to eat any time of the day, and The permissive social norm to eat any time of the day, and however one wants however one wants

Resisting TemptationsResisting Temptations

Self-Control StrategiesSelf-Control Strategies

►Cue managementCue management►Eliminating optionsEliminating options►Imposing costImposing cost►Setting up rewards contingent on the choosing delayed Setting up rewards contingent on the choosing delayed

rewardreward► Delays & cooling off period Delays & cooling off period

►Automatic self-regulation (IfAutomatic self-regulation (IfDo rules)Do rules)

Policy Implications Policy Implications

► The competing brain region implies developing new The competing brain region implies developing new prevention approaches to influence the relative prevention approaches to influence the relative control of these two brain regions: (1) decrease control of these two brain regions: (1) decrease activation of impulsive brain regions and (2) increase activation of impulsive brain regions and (2) increase activity in executive brain regions. activity in executive brain regions.

► The role for “cognitive” policies, including the The role for “cognitive” policies, including the suppression of certain environmental cues.suppression of certain environmental cues.

► Paternalistic policies: Because such present-biased Paternalistic policies: Because such present-biased people may not behave in their own long-run best people may not behave in their own long-run best interests, there is a role for policymakers to create interests, there is a role for policymakers to create incentives that will motivate individuals to maintain a incentives that will motivate individuals to maintain a pattern of behavior. pattern of behavior.

ConclusionConclusion

►People devalue a given future event at different People devalue a given future event at different rates, depending on how far away it is.rates, depending on how far away it is.

►People do not act in their long-term self-interest People do not act in their long-term self-interest – they impose a cost on future selves– they impose a cost on future selves

►Consistency (rationality) is not costless: requires Consistency (rationality) is not costless: requires effort & investmenteffort & investment

►The cost vary among individuals by the amount The cost vary among individuals by the amount of limited willpowerof limited willpower

Thank YouThank You