Download Applying Behavioral Economics to Weight

Applying Behavioral Economics to
Weight-Loss
Why Dieters Fail?
Shahram Heshmat
Department of Public Health; University of Illinois at Springfield
(UIS), Springfield, IL
Corresponding author: Tel: 217-206-7878,
Fax: 217-206-7807
E-mail address: [email protected]
The Second National Predictive Modeling Summit
September 22 – 23, 2008
Washington,
Issues
► The
21st century will be the Century of behavior
change. Changing everyday, long-term behavior is the
key to adding years and quality to our lives -Wansink
(2006)
► There
exist mountains of very good science about what
constitutes a healthy lifestyle, but still our leading cause
of death is I’ll Do It Starting Tomorrow – people
continuing to eat poorly, smoke, not exercise, drink in
excess. - Robert Sapolsky
Research Questions
► Why
is it that people who are able to
successfully initiate changes in their behavior
have difficulty maintaining it over time?
► How to overcome the problem that individuals
are not always able to maximize their own wellbeing?
Purpose
► To
present some insights from behavioral economics to
explain why people fail to maintain healthy behavior.
This is accomplished by looking at conditions in which
the decision making is impaired or even breaks down.
► Knowing why people fail to maintain a desired
preference for healthy behavior over time is an essential
ingredient in the development of effective weight-loss
management.
► To draw implications for obesity prevention.
Trends
Obesity prevalence: United States, 2005–2006
Obesity across countries:
Percentage of population aged 15 and over, with a BMI greater 30 (2003). Source: OECD Fact book 2005.
Causes of Obesity
► Within
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the past several decades, five developments
have tipped the balance between caloric intake and
expense to an unfavorable equilibrium:
Expanding labor market opportunities for women
Increased consumption of food away from home
Rising costs of healthy foods relative to unhealthy
foods
Growing quantity of caloric intake with declining
overall food prices
Decreased requirements of occupational and
environmental physical activity
Poverty and obesity
► The
Engel’s law: consuming energy-dense foods
(e.g., doughnuts, potato chips), and energy-dense
diets, is an important strategy used by low-income
consumers to stretch the food budget
► Energy-dense foods carry a lower price tag, which
allows for a higher energy consumption at a lower
cost. E.g., a dollar buys 1,200 calories in the form of
a package of cookies (Chips Ahoy!), but only 250
calories in that of a bag of carrots.
The health risks of obesity
► Overweight
and obesity have become to diabetes what
tobacco is to lung cancer.
► Roughly 60% of all cases of diabetes can be directly
attributed to weight gain.
► Obese adults have about 10 times the risk of developing
diabetes compared with normal-weight adults.
► The health care costs attributed to overweight is over
$100 billion per year – or 9.1% of the country’s health
expenditure.
How do we evaluate the rise in body weight, and
the harm to people’s health?
► It
is a choice to be fat: the person actually
prefers eating more and being fat to eating less
and being thinner.
► He can’t help what he is doing.
Standard Model of Economic Choice
► The
objective is to maximize utility [U = f (X, W)],
subject to a money income constraint and a time
constraint.
► We act consistently - A good decision is to choose and
pursue an outcome that is liked best when it is gained,
from among all available options.
► Revealed preference
► Opportunity set (e.g., a large number of TV channels
increase life satisfaction)

The rational choice theory has only two concepts to explain the obesity
epidemic: 1) overweight individuals have poor health and nutrition
information, 2) they actually prefers eating more and being fat to eating less
and being thinner.

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.
►
Overweight and happiness

Behavioral economics, on the other hand, assumes that people are susceptible
to temptations and they tend to pursue immediate gratification in way that they
themselves do not appreciate in the long run.
What is behavioral Economics?
► The
field of behavioral economics blends insights of
psychology and economics. It uses insights from
psychology to develop more “realistic” models of
individual decision-making, in which people often do
things that are not in their best interests.
► Behavioral economics explains why people appear so
inconsistent when their behavior is viewed through the
lens of the standard economic model.
Choice over time
►
A key concept in behavioral economics is that of how
delayed rewards are discounted by individuals, and
deviation from the rational-choice paradigm.
► Discounting of delayed rewards refers to the
observation that the value of a delayed rewards is
discounted (reduced in value or considered to be
worth less) compared to the value of an immediate
rewards. Higher discount rates give greater weight to
benefits and costs accruing early in the life cycle than
do lower discount rates.
The Seductive Present-Moment
►
Insights from behavioral economics indicate that
people are often of two minds when it comes to
intertemporal choice - they are often powerfully
motivated to take myopic actions, such as eating
highly caloric foods, while recognizing
simultaneously that these activities are not in their
self-interest.
►
Such preferences imply that people have self-control
problems wherein they are unable on a moment-bymoment basis to behave in their own long-term best
interest.
An Example:
Option A: Starting an exercise program today
► Costt0
= 8, Valuet1 = 10 => net gain = 2; net gain
(discounted @ 50%) = -8 +1/2(10) = -3
► So we are reluctant to start exercising today.
Option B: Starting tomorrow:
► Costt1 = 8, Valuet1 = 10 => net gain (time
adjusted) = -8 (1/2) +1/2(10) = 1
► Hence, everyone is enthusiastic about going to the
gym tomorrow.
Time
Preference Reversal
Time
Preference reversal
► A surge
of preference for the
less valued alternative when
it looms close.
► Indulge now and abstain
tomorrow: the long-term
motivation is constantly
threatened by short-term
motives
► We are strangers to ourselves
Summary
► In
sum, individuals display behavior that is
dynamically inconsistent. Initially people prefer
X to Y, but they later choose Y over X. How can
such behavior be understood? What is about the
immediacy of an event that blinds us to better
alternatives that we might have if we could only
wait a little for them?
Self-control problem
The Mechanisms of Preference Reversal
►
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The Duplex Mind: Impulsive vs. Reflective
Decision-Making
Asymmetric warfare between emotion and
cognition
Our emotional brain has a hard time imagining
the future, even though our logical brain
clearly sees the future consequences of our
current actions.
Affective and Deliberating
Processing
The Primacy of Emotion
Willpower
► Willpower
is an important ingredient in self-
control.
► Self-control functions like a muscle that can be
depleted with use but strengthened over time.
Dieting as a choice over time
►
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.
►
The two principal reasons given by dieters for wanting to lose weight:
health and attractiveness
►
Dieting behavior can be viewed as making constant trade-offs between
immediate and delayed benefits under uncertain conditions (“a moment on
the lips, a lifetime on the hips,”)
►
This difference in the timing of costs and benefits constitutes one of the
major obstacles to dieting. Food brings immediate gratification, while the
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
another to maintain it.
Why Dieters Fail?
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Visceral feelings: Hunger, Stress
Cue-Elicited Behavior
Attentional Bias
Willpower (Ego Depletion)
Hot-cold empathy gap: underestimate the power of
craving
“What the hell” effect
Alcohol myopia
Social Influence
Awareness of self –control problem
Explaining Overweight in Modern
Society
Overweight in modern society
►
The role of stress (e.g., increased demand on women at home and
on the job)
► Homeostatic vs. Hedonic hunger (wanting)
► Wanting (choice) and Liking (hedonic reaction) are separable
systems
► Transient irrational wanting comes and goes with the cues.
► Wanting system seems more sensitive to the widespread
availability of highly palatable food, which creates hedonic
hunger (“perceived deprivation”)
► The permissive social norm to eat any time of the day, and
however one wants
Resisting Temptations
Self-Control Strategies
►Cue
management
►Eliminating options
►Imposing cost
►Setting up rewards contingent on the choosing delayed
reward
► Delays & cooling off period
►Automatic
self-regulation (IfDo rules)
Policy Implications
► The
competing brain region implies developing new
prevention approaches to influence the relative
control of these two brain regions: (1) decrease
activation of impulsive brain regions and (2) increase
activity in executive brain regions.
► The role for “cognitive” policies, including the
suppression of certain environmental cues.
► Paternalistic policies: Because such present-biased
people may not behave in their own long-run best
interests, there is a role for policymakers to create
incentives that will motivate individuals to maintain a
pattern of behavior.
Conclusion
► People
devalue a given future event at different
rates, depending on how far away it is.
► People do not act in their long-term self-interest
– they impose a cost on future selves
► Consistency (rationality) is not costless: requires
effort & investment
► The cost vary among individuals by the amount
of limited willpower
Thank You