Effect of price, variety, and caloric cost on food

purchases in corner stores in NYC

Mindy Chang, MPH, DVMCity Harvest Evaluation Dept.

November 2014

Disclosure

I have no relationships to declare

2

Introduction• Obesity

– 34.9% (78.6 million) U.S. adults are obese1

– Disproportionately affect groups with the highest poverty rates2

– In NYC, 22% are obese3

• Rates of obesity increases as poverty increases4

– 15.7% with highest income are obese

– 26.8% with lowest income are obese

• Food environment of low-income neighborhoods

– Predominantly corner stores5

• Charge higher prices for healthier food6

• Limited availability of fruits and vegetables7

• Primarily offer inexpensive snack foods8

– Candy, fried snacks

– Sugar sweetened beverage

– Packaged bakery product

– Presence of corner stores associated with increased risk of obesity9

3

Introduction• City Harvest Healthy Corner Store

program– Work with corner stores to encourage

• Expansion of produce sales

• Expansion of healthy choices in stores

• Question: What factors will affect customer purchases

4

Methods

• Inventory of corner stores (n=29)– List varieties of produce, potato chips and

candy– List prices of produce, potato chips and

candy– List sizes of potato chips and candy

• Customer surveys (n=437)– What do you purchase most often from

corner stores– How far is supermarket, corner store and

fast food restaurant from where you live– Did you notice food advertisements

• Pictures of ads present in 2 block radius around corner store

5

Methods• Data collection

– June 2013 to September 2014

• Inventory of corner stores (n=29)– Bedford-Stuyvesant (n=11)– South Bronx (n=9)– Long Island City/Astoria (n=4)– Stapleton (n=2)– Washington Heights/Inwood (n=3)

• Customer surveys (n=437)– Gender

• Female 45%

– Race/ethnicity• Black 41%• Hispanic 36%

– Average age 41.3 years old– Average education level: High school graduate/GED

6

What are customers buying-food (n=437)

7

Fresh fruit Fresh vegetable Canned fruit Canned vegetable

Chips Candy

32%

24%

9%8%

36% 36%

Factors that may affect corner store purchases

• Distance to stores – Supermarket– Corner stores – Fast food restaurants

• Quality of produce available in corner stores

• Number of varieties available of produce and snack foods at corner stores

• Cost of produce and snack foods at corner stores

• Advertising

Factors that may affect purchases: Distance to stores

• Distance to supermarkets, corner stores and fast food restaurants categorized as– Close (less than 3 blocks)–Medium (3 to 6 blocks)– Far (more than 6 blocks)

Store type Range of blocks to store

Average number of blocks to store (+/- stdev)

Supermarket 0-20 3.17 (+/-3.18)

Corner store 0-8 1.36 (+/-0.98)

Fast food restaurant 0-25 3.36 (+/-3.35)

Factors that may affect purchases: Distance to stores

Corner store Supermarket Fast food restaurant

31% 32% 31%27% 26% 26%

40%36%

29%

% of Customer who Purchase Fruits

Close Medium Far

Corner store Supermarket Fast food restaurant

23% 24% 24%

33%

16%

26%

20%

33%

17%

% of Customers who Purchase Vegetables

Close Medium Far

Factors that may affect purchases: Distance to store

Corner store Supermarket Fast food restaurant

38%36%

33%

0%

42% 42%

20% 21%

38%

% of Customers who Purchase Chips

Close Medium Far

Corner store Supermarket Fast food restaurant

37% 38%36%

33% 32%

42%

0%

42%

27%

% of Customers who Purchase Candy

Close Medium Far

Factors that may affect purchases: Quality of produce

• Quality of produce categorized as– Poor (1)– Fair (2)– Good (3)Average fresh fruit quality

2.4 (+/- 0.49)

Average fresh vegetable quality2.2

(+/- 0.49)

Factors that may affect purchases: Quality of produce

Fruit quality Vegetable quality

15%

24%

40%

24%

31%

24%

Poor Fair Good% Customers who purchase fruits

% Customers who purchase vegetables

Factors that may affect purchases: Variety

• Variety of produce, chips and candy available categorized as (based on tertile)– Low variety–Medium variety– High variety

Food type Range of variety Average variety (+/- stdev)Fruit 0-16 7.18

(+/-3.92)

Vegetable 0-20 9.28(+/-4.89)

Potato chips 0-46 14.14 (+/-11.64)

Candy 0-165 38.48(+/-33.57)

Factors that may affect purchases: Variety

Fruit Vegetable Potato Chips Candy

13% 13%

37%41%

34%30% 29%

31%

55%

30%

43%

31%

Low variety Medium variety High variety

% Customers who purchase chips

% Customers who purchase vegetable

% Customers who purchase fruit

% Customers who purchase candy

*

*

*p <0.05

Factors that may affect purchases: Cost (per ounce)

• Candy and potato chips are significantly more expensive– Contradictory to what customers are purchasing

• Cost per ounce of produce, chips and candy available categorized as (based on tertile)– Low cost– Medium cost– High cost

*p<0.05 significantly different compared to chips or candy

Food type Range of cost per ounce

Average cost per ounce (+/- stdev)

Fruit $0.05-$0.34 $0.12*(+/-0.04)

Vegetable $0.04-$0.33 $0.12*(+/-0.05)

Potato chips $0.17-$1.00 $0.41(+/-0.12)

Candy $0.01-$1.25 $0.47(+/-0.26)

Factors that may affect purchases: Cost (per ounce)

Fruit Vegetable Potato Chips Candy0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

34%

26%

43%41%

32%

23%

36% 37%

14%

7%

28%

17%

Low cost Medium cost High cost

% Customers who purchase chips

% Customers who purchase vegetable

% Customers who purchase fruit

% Customers who purchase candy

*p <0.05

Factors that may affect purchases: Cost (per calorie)

• Potato chips and candy is significantly cheaper per calorie

• Cost per calorie of produce, chips and candy available categorized as (based on tertile)– Low cost– Medium cost– High cost

• $0.0043 +/- 0.0024 per calorie

*p<0.05 significantly different compared to chips or candy

Food type Range of cost per calorie

Average cost per calorie (+/- stdev)

Fruit 0.33¢-7.14¢ 1.76¢(+/-1.233)

Vegetable 0.19¢-3.62¢ 1.11¢*(+/-0.53)

Potato chips 0.11¢-0.65¢ 0.27¢(+/-0.08)

Candy 0.09¢-1.15¢ 0.43¢(+/-0.24)

Factors that may affect purchases- Cost (per calorie)

Fruit Vegetable Potato Chips Candy

35%

27%

39%41%

24%

12%

33%36%

14%

37% 38%

15%

Low cost Medium cost High cost

% Customers who purchase chips

% Customers who purchase vegetable

% Customers who purchase fruit

% Customers who purchase candy

*

*

*p <0.1

*

Factors that may affect purchases: Advertising

• Number of advertisements of produce and fast foods chips in neighborhood categorized as (based on tertile)– Low number of ads– Medium number of ads– High number of ads

Ads for type of food

Range of number of ads seen

Average number of ads seen

Fruits and vegetables

0-9 2.71

Fast foods 0-14 5.36

Factors that may affect purchases: Advertising

Percent of customers who notice produce ads

Percent of customers who notice fast food ads

38%

62%

37%

65%

25%

78%

Low number of ads Medium number of ads High number of ads

Percent of customers who purchased produce

Percent of customers who purchased chips

25%

55%

27%24%22%

25%

Low number of ads Medium number of ads High number of ads

*

Conclusions• Factors that showed significant association

with customer reported purchases from corner stores– Number of varieties available– Cost of produce (per calorie)

• Factors that did not show any significant association– Distance to store– Quality– Advertising

• Program should focus on availability – Increasing variety of fruits and

vegetables sold• Work with suppliers, retailers and policy

makers to affect prices – May be difficult to achieve

Limitations• Self-report• Sample size

– 437 customers– 29 corner stores

• Assessment of quality of produce– Subjective process

• Number of varieties available of produce– Seasonality not accounted for

• Cost of produce at corner stores– Approximation of produce based on average size and

calorie content of produce

• Advertising– Only print ads present in neighborhood– May not have captured all ads – TV commercial ads not accounted for

Works cited1. Centers for Disease and Prevention. Overweight and Obesity: Adult

Obesity Facts. Accessed Nov 11, 2014. www.cdc.gov/obesity/data/adult.html

2. Arfken CL, Houston CA. Obesity in inner-city African Americans. Ethn Healthy. 1996 Dec; 1(4): 317-26.

3. New York City Department of Health and Mental Hygiene. Obesity. Access Nov 11, 2014. www.nyc.gov/html/doh/html/living/obesity.shtml

4. New York City Department of Health and Mental Hygiene. Community Health Survey (2012): public use dataset accessed on Nov 11, 2014. http://www.nyc.gov/html/doh/html/data/chs-data.shtml

5. Cannuscio CC, Tappe K, Hillier A, Buttenheim A, Karpyn A, Glanz K. Urban food environments and residents shopping behaviors. Am J Prev Med. 2013; 45(5):606-614.

6. Krukowski RA, West DS, Harvey-Berino J, Elaine Prewitt T. Neighborhood impact on healthy food availability and pricing in food stores. J Community Health. 2010; 35: 315-20.

7. Leone AF, Rigby S, Betterley C, et al. Store type and demographic influence on the availability and price of healthful foods, Leon County, Floriday, 2008. Prev. Chronic Dis.. 2011; 8, A140.

8. Lucan SC, Karpyn A, Sherman S. Storing empty calories and chronic disease risk: Snack-food products, nutritive content and manufacturers in Philadelphia corner stores. J Urban Health. 2010; 287: 394-409.

9. Bodor JN, Rice JC, Farley TA, Swalm CM, Rose D. The association between obesity and urban food environments. J Urban Health. 2010; 87(5):771-81.

Special Thanks To

Veronica Uzoebo

Sally Cooper

Sheilah Crowley

Jennifer McLean

Raul Barrios

Touro Interns

Aditi Puri

Sarah MacLeod

CUNY Corp Interns