field studies of healthy eating interventions in …...marketers / retailers-avoid regulation -avoid...
TRANSCRIPT
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Jason Riis, Harvard Business School
Field Studies of Healthy Eating Interventions in Retail Settings
Copyright © President & Fellows of Harvard College.
Obesity and associated diseases
Obesity – very prevalent
Diabetes – rates are rising
Cost – very high
Cause – eating too many calories
Minorities – particularly susceptible
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Stakeholders in obesity/diabetes trends: Incentives aligned?
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Healthcare Payers
~$2000/obese patient
(additional healthcare cost)
Policy Makers
-public health
-national competitiveness
-not just U.S.
Employers
~$500/obese employee
(productivity loss)
Consumers
-want to lose weight (health, cost, beauty)
-know they overeat
-rising healthcare costs
Marketers / Retailers
-avoid regulation
-avoid bad PR
-long term – can this continue?
-short term – need healthy consumers
Lots of work on consumer biases and overeating
• Wansink et al (2005) – Bottomless Soup Bowl
• Wansink & Chandon (2006) – Low-fat labels lead to overconsumption
• Chernev & Gal (2010) – Averaging bias
• …
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What can retailers / policy makers do?
• Price (taxes / subsidies)
• Information (raw)
• “Strong Nudge”• Awareness of nudge• Aligned with existing goal• Directive (but not too directive)• Immediately Actionable
• Change Defaults
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Triggers self control?
By-passes self control
Two strong nudges
• “Strong Nudge”• Awareness of nudge• Aligned with existing goal• Directive (but not too directive)• Immediately Actionable
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1. Invitation to downsize
2. Traffic light labels
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Pilot study: Attitudes to portions
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How big are the portions at the restaurants you typically visit? (N=142)
Usually too small
4%
Usually about right
59%
Usually too large
37%
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Pilot study: Attitudes to portions
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At the restaurants you go to, how often do you specifically request a smaller portion than is offered on the menu? (N=81)
Almost never
89%
Often
10%
Most of the time
1%
If the restaurants you go to started offering optional “downsized” portions at a very small discount, how often would you accept? (N=61)
Almost never
38%
Often
51%
Most of the time
11%
Pilot study: Attitudes to portions
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At the restaurants you go to, how often do you specifically request a smaller portion than is offered on the menu? (N=81)
Almost never
89%
Often
10%
Most of the time
1%
How would you react if you were offered a “downsized” portion at a very small discount? (N=81)
Feel obliged to accept
7%
Happily accept
42%
Not accept
46%
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Pilot study: Attitudes to portions
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If the restaurants you go to started offering optional “downsized” portions at a very small discount, how often would you accept? (N=61)
Almost never
38%
Often
51%
Most of the time
11%
Why would you accept? (N=38)
To avoid eating too much
55%
To save money
24%
To avoid wasting food
21%
Three Studies at Panda Express: Questions
Study 1 Do customers spontaneously request smaller portions? Do customers accept nudges to take smaller portions for no discount or
for a nominal discount? If customers accept smaller portion nudges, do they compensate by
taking more calories in other parts of the meal?
Study 2 Are nudges more effective than calorie labels at reducing calorie
consumption?
Study 3 Do customers who take less food, actually eat less food? 12
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Ordering a meal at Panda Express
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Fried rice
Steamed rice
Chow mein
Mixedveggies
Orangechicken
Beijing beef
BBQ pork …
Mushrmchicken
Broccoli beef
Country tofu …
Step 2Order side dish
Step 3Order entrée(s)
Step 4Pay
$
Step 1Order meal size
How the nudge worked
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Fried rice
Steamed rice
Chow mein
Mixedveggies
Orangechicken
Beijing beef
BBQ pork …
Mushrmchicken
Broccoli beef
Country tofu …
Step 2Order side dish
Step 3Order entrée(s)
Step 4Pay
$
Step 1Order meal size
“Would you like to cut more than 200 calories from your meal by taking a half portion of your side dish?”
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Panda Express
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Panda Express
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Panda Express
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Orange chicken 440 calories
Beijing Beef 660 calories
Steamed Rice 420 calories
Study 1 Design – Summer 2009
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Sun Mon Tue Wed Thu Fri Sat
BASELINE BASELINE NUDGEno
discount
NUDGEno
discount
BASELINE BASELINE NUDGE25¢
discount
NUDGE25¢
discount
“Would you like to cut more than 200 calories from your meal (and save 25¢) by taking a half portion of your side dish?”
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Study 1 Customers – Summer 2009
• N = 283 receipts plus estimated gender and age• Exclusions:
• Group order• Partial meal order• Lost receipt• Ambiguous receipt
• 75% male• Median estimated age = 26
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Proportion taking half sized side dish portion
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Sun Mon Tue Wed Thu Fri Sat
BASELINE BASELINE NUDGEno
discount
NUDGEno
discount
BASELINE BASELINE NUDGE25¢
discount
NUDGE25¢
discount
1% 35%
4% 32%
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Proportion taking half sized side dish portion
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Sun Mon Tue Wed Thu Fri Sat
NUDGEno
discount
NUDGEno
discount
NUDGE25¢
discount
NUDGE25¢
discount
35%
32%
Calories per customer (Nudge condition only), n=164
464505
255
538
0
100
200
300
400
500
600
Side Dish Entrees
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Nudge Rejecters Nudge
Rejecters
Nudge Accepters
Nudge Accepters
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Calories per customer (Nudge condition only), n=164
464505
255
538
0
100
200
300
400
500
600
Side Dish Entrees
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Nudge Rejecters Nudge
Rejecters
Nudge Accepters
Nudge Accepters
Proportion taking half sized side dish portion
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Sun Mon Tue Wed Thu Fri Sat
BASELINE BASELINE NUDGEno
discount
NUDGEno
discount
BASELINE BASELINE NUDGE25¢
discount
NUDGE25¢
discount
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Calories per customer, N=283
480
530
396
516
0
100
200
300
400
500
600
Side Dish Entrees
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BaselineBaseline
Nudge
Nudge
Calories per customer, N=283
480
530
396
516
0
100
200
300
400
500
600
Side Dish Entrees
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BaselineBaseline
Nudge
Nudge
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Paper 1 Conclusions
Study 1 Do customers spontaneously request smaller portions? NO Do customers accept nudges to take smaller portions for no discount or
for a nominal discount? YES If customers accept smaller portion nudges, do they compensate by
taking more calories in other parts of the meal? NO
Study 2 Are nudges more effective than calorie labels at reducing calorie
consumption? YES
Study 3 Do customers who take less food, actually eat less food? YES 27
Restaurants can help customers avoid overeating by providing self control nudges.
Strong Nudge … may not be needed over time
Introduce “right-sized” language With time, it could become part of fast food “script” Others customers may hear it
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March, 2012
Food Choices of Minority and Low-Income Employees: A Cafeteria Intervention
September, 2012
Strategies for solving self control problems
Pre-empt self control – the “Weak Nudge” Change default Choice architecture
Trigger self control – the “Strong Nudge” Awareness of nudge Aligned with existing goal Directive (but not too directive) Immediately Actionable
“Consume often”
“Consume less often”
“There’s a better choice in green or yellow”
TRAFFIC LIGHT LABELS
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Setting: Main cafeteria, Massachusetts General Hospital (MGH)
Over 6,000 employees and visitors visit the main cafeteria per day
Operated by the MGH Food and Nutrition Services
$30,000 revenue / day
Data: All register data for 9 months
~3 million items
PHASE 2: STRONG + WEAK
PHASE 1: STRONG
PHASE 0:BASELINE
Study Design and Timeline
December 1, 2009
March 1, 2010
June 1,2010
Sept 1,2010
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PHASE 1: STRONG
Study Design and Timeline
December 1, 2009
March 1, 2010
June 1,2010
Sept 1,2010
Phase 1: Labeling (RYG)
All food and beverages in the cafeteria were labeled as red, yellow, or green based on an algorithm we developed from USDA food pyramid guidelines
“Consume often”
“Consume less often”
“There’s a better choice in green or yellow”
Self control may kick in with regular reminders that you are choosing the unhealthy (red) item
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PHASE 2: STRONG + WEAK
Study Design and Timeline
December 1, 2009
March 1, 2010
June 1,2010
Sept 1,2010
Phase 2: Labeling + Choice Architecture (CA)
• Implemented after Phase 1
• “Choice architecture” intervention • Make healthy foods (green) more convenient/visible• Make unhealthy foods (red) less convenient/visible
• Changes were made over a weekend and not advertised to cafeteria patrons
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Before ……………………………. and After Choice Architecture
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Choice Architecture: Water everywhere
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Data analysis
Calculated proportion of sales that were red, yellow, and green during each 3 month period (baseline, Phase 1, Phase 2)
Tested significance of relative change in 3-month sales of red and green items between phases Baseline - Phase 1 Phase 1 - Phase 2 Dependent variables: red or green items Independent variable: Phase Controlled for day of week
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Results 1 – Overall choice patterns
Excluded weekends and holidays (including Dec 24 – Jan 3)
Excluded “boil water” emergency (May 1 – May 5)
Salad bar purchases assigned Green (2/3 of items were green, 1/3 yellow)
~1 million items sold each period
~$30,000 revenue / day
PHASE 2: STRONG + WEAK
PHASE 1: STRONG
PHASE 0:BASELINE
Study Design and Timeline
December 1, 2009
March 1, 2010
June 1,2010
Sept 1,2010
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Sales of all cafeteria items during baseline, Phase 1, and Phase 2
0
5
10
15
20
25
30
35
40
45
Red items Yellow items Green items
Baseline
Phase 1 (RYG)
Phase 2 (CA)
% o
f tot
al c
afet
eria
sal
es
Relative change in sales of red and green items in Phase 1 and Phase 2
PHASE 1 (RYG) PHASE 2 (CA)
Proportion of baseline sales
(N=977,793)
Relative change from baseline P value*
Relative change from
Phase 1 P value*
All red items 24.9% -9.2% <.001 -4.9% <.001
All green items 42.2% +4.5% <.001 -0.5% <.001
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Sales of cold beverages during baseline, Phase 1, and Phase 2
0
10
20
30
40
50
60
Red beverages
Yellowbeverages
Greenbeverages
Baseline
Phase 1 (RYG)
Phase 2 (CA)
% o
f tot
al b
ever
age
sale
s
Relative change in sales of red and green cold beverages in Phase 1 and Phase 2
PHASE 1 (RYG) PHASE 2 (CA)
Proportion of beverage sales at baseline(N=199,153)
Relative change from baseline P value*
Relative change
from
Phase 1 P value*
All red beverages
26.1% -16.5% <.001 -11.4% <.001
All greenbeverages
51.7% +9.6% <.001 +4.0% <.001
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Sales of bottled water and soda during baseline, Phase 1, and Phase 2
0
5
10
15
20
25
Water Diet soda Regular soda
Baseline
Phase 1 (RYG)
Phase 2 (CA)
% o
f all
cold
bev
erag
es
Relative change in sales of water and soda during Phase 1 and Phase 2
PHASE 1 (RYG) PHASE 2 (CA)
Proportion of beverage sales at baseline(N=199,513)
Relative change from baseline P value*
Relative change from
Phase 1 P value*
Water 13.6% -2.4% <.001 +25.8% <.001
Diet soda 19.6% +9.2% <.001 -0.8% <.001
Regular soda 19.5% -23.1% <.001 -5.9% <.001
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Comparison site analysis: PHASE 1 PHASE 2
Proportion of baseline sales
Absolute change from baseline
Between group difference
Absolute change from Phase 1
Between group difference
Red Chips
Intervention 36.7% -0.8% -3.9% -5.2% -11.2%
Comparison 77.4% +3.1% +6.1%
Red Sandwich
Intervention 14.6% +2.5% -0.3% -2.7% -0.7%
Comparison 10.3% +2.8% -2.0%
Green Sandwich
Intervention 24.0% +0.5% +1.9% +7.5% +4.3%
Comparison 20.2% -1.4% +3.2%
Bottled water
Intervention 13.6% -0.3% -1.1% +3.4% +3.2%
Comparison 18.6% +0.8% +0.3%
Results 2 – “Platinum Plate Users”
4,642 employees
73% white, 10% black, 7% Asian, 10% Latino
53,371 transactions during baseline
131,417 items during baseline
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Trends by Race
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02
04
06
08
01
00
pe
rce
nt
Black Latino Asian White
B L C B L C B L C B L C
B = Baseline, L = Labeling, C = Choice Architecture
Red Yellow Green
Intervention effects by race -- Overall purchases
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Baseline Phase 1 Phase 2
Red Purchases AverageRelative percent change
from baselineRelative percent
change from Phase 1Overall 20.9 -11.2 * -4.1 *White 19.3 -12.1 * -5.0 *Asian 21.3 -6.1 -7.1Latino 24.7 -11.4 * 3.7Black 29 -10.1 * -3.0
Green Purchases
Overall 45.4 6.6 * -1.9 *White 46.5 6.6 * -1.5 *Asian 46.9 3.9 -1.9Latino 43.1 9.4 * -5.2 *Black 37.6 6.7 * -2.4
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Intervention effects by race -- Beverage purchases
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Baseline Phase 1 Phase 2
Red Purchases AverageRelative percent
change from baselineRelative percent change
from Phase 1Overall 24 -23.8 * -14.2 *White 21.8 -25.6 * -17.1 *Asian 28.2 -17.1 * -18.1 *Latino 29.1 -23.3 * -3.3Black 33 -20.6 * -5.9
Green Purchases
Overall 59.3 5.6 * 2.3 *White 62.8 5.8 * 2.4 *Asian 51.4 5.4 0.5Latino 51.4 5.2 -0.9Black 47.2 3.8 5.8
Intervention effects on calories and price per beverage by subgroups
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Average calories (kcal) per
beverage at baseline
Change in calories (kcal) per beverage
from baseline to Phase 2
Average price per beverage at
baseline
Change in price per beverage
from baseline to Phase 2
Overall 95 -15 * $1.34 $0.00
White 87 -15 * $1.30 $0.02 *
Asian 112 -14 * $1.35 -$0.02
Latino 113 -12 * $1.42 -$0.04
Black 126 -17 * $1.42 -$0.04 *
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Conclusions
• Traffic light labels are an effective “strong nudge”
• Effectiveness increased in context of healthy choice architecture
• Particularly effective for beverages
• Effective with minority / lower income employees as well
• Could improve the reach and effectiveness of calorie labels
• Traffic light labeling: It’s not just product information
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Two strong nudges
• “Strong Nudge”• Awareness of nudge• Aligned with existing goal• Directive (but not too directive)• Immediately Actionable
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1. Invitation to downsize
2. Traffic light labels
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Closing thoughts
• Obesity is a marketing problem / retailing opportunity
• Strong nudges can work in retail settings and are feasible
• More field studies are needed
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END
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