THE GROCERY STORE AND YOU: IS YOUR FOOD HEALTHY?

By Ricky Benner and Stefanie RichmanBy Stefanie Richman and Ricky Benner

QUESTION:

Does the average Wegmans product contain enough nutrition* to meet the FDA’s RDI values?

*Testing Total Fat, Sodium, and Vitamin A content

PROCEDURE Use Wegmans online product list as sampling

frame This list is common to all Wegmans Exclude non-edible products

Take stratified sample of 102 products by department Determine what percentage of all edible products are

in each department Take SRS within each department

Products already numbered in each dept. Generate random numbers on TI-84

Ex: Dairy contains 1693 products, about 7% of population (7/102), so we use randInt(1,1693,7) to generate 7 random products

Locate products in online list Record products’ nutritional info per serving: calories, total fat,

sodium, total carbohydrates, sugar, protein, and Vitamin A

We entered our data into Fathom and created the appropriate histograms and tests

BACKGROUND ON Was founded in 1916 by John and Walter Wegman More than 75 stores spread across New York, Pennsylvania,

New Jersey, Virginia and Maryland Plans to open a store in Massachusetts this year Most Wegmans stores are the “superstore” or “megamarket”

type, which includes a large area with large variety of foods aimed at an upscale market and the Market-Café in store dining areas

In 1979, Wegmans began branding their own products offering basic commodities with a lower price than the national brands

In 1992, it started a line of health products called "Food You Feel Good About"

The next sub-brand launched was "Italian Classics" In 1995, Wegmans introduced its imported pastas, canned

tomatoes, olive oils, etc In 2002, Wegmans launched its own line of organic products

BACKGROUND ON HUMAN NUTRITION

People require energy to function This energy comes in the form of food When people eat then digest, the energy stored in

the food is converted into chemical energy, which is then used or stored in the body

Specific nutrients are absorbed by the body to maintain proper functioning 7 Basic nutrients: carbohydrates (includes sugars),

proteins, fats, vitamins (includes Vitamin A), minerals (includes sodium), fiber, water

Deficiencies in specific nutrients cause illnesses Chronic consumption of excessive nutrients like

fat and sodium cause illnesses like obesity

BACKGROUND ON THE RECOMMENDED DAILY INTAKE The Recommended Daily

Intake (RDI) is the amount of a nutrient per day the FDA claims is sufficient for about 98% of the US population

The Daily Value (DV) included on nutrition labels tells how much of a nutrient is in one serving of a product, and the % Daily Value is the DV as a percentage of the RDI The %DV makes it easier

for people to fill their RDI quota

RDI Values of 8 Macronutrients

NutrientUnit of Measure

Daily Values

Total Fat grams (g) 65

  Saturated fatty acids

grams (g) 20

Cholesterol milligrams (mg)

300

Sodium milligrams (mg)

2400

Potassium milligrams (mg)

3500

Total carbohydrate

grams (g) 300

  Fiber grams (g) 25

Protein grams (g) 50

BACKGROUND ON NUTRITION LABELING

In 1990, the FDA introduced the controversial Nutrition Labeling and Education Act, requiring companies to mark their food products with the “Nutrition Information” label, becoming effective in May 1994.

Now called “Nutrition Facts,” the label requires a product’s DVs and %DVs to be visibly displayed on the product’s packaging

Calories, fat content, protein, vitamins, and other DVs are included

TOTAL FAT (G) PER SERVING VS. FREQUENCY IN SAMPLE HISTOGRAM

5

10

15

20

25

30

35

40

45

Total_Fat_g

0 2 4 6 8 10 12 14 16 18 20

Collection 1 Histogram Right skewed Unimodal Mean is 3.95012 grams,

which is a low fat content Range is from 0 to 18

grams, which means some products have a low fat content and some have a high fat content

A lot of items we sampled have between 0 to 2 grams of fat in them, which means the items have a low fat content

1 SAMPLE T-TEST: FAT

Hypothesis: Ho: µ = 4.0393 (grams of fat) Ha: µ < 4.0393 (grams of fat)

Conditions:1. Randomization 2. Population ≥ 10n 3. Normal population or n ≥ 30

Checked:1. Sample is representative of population 2. n = 102 102 X 10 = 1020 There are more than

1,020 food items in Wegmans 3. n = 102 ≥ 30

1 SAMPLE T-TEST: FAT CONT.

All conditions met, Student’s t distribution, 1 Sample t-test

Mechanics: t = = 3.95012 – 4.0393 = -0.198 0.450481 P (t < -0.198│df = 101) = 0.42 k

Conclusions: We fail to reject the Ho because p-value of 0.42

is greater than the alpha equal to 0.05. We have sufficient evidence that the true

average fat content in Wegmans food items per serving is equal to 4.0393 fat grams.

SODIUM (MG) PER SERVING VS. FREQUENCY IN SAMPLE HISTOGRAM

5

10

15

20

25

30

35

40

Sodium_mg

0 200 400 600 800

Collection 1 Histogram Right skewed Unimodal Mean is 149.199

milligrams, which is a low sodium content

Range is from 0 to 800 milligrams, which means some items have a low sodium content and some have a high sodium content

A lot of items we sampled have between 0 and 200 milligrams of sodium in them, which means the items have a low sodium content

1 SAMPLE T-TEST : SODIUM

Hypothesis: Ho: µ = 142.9303 (milligrams of sodium) Ha: µ < 142.9303 (milligrams of sodium)

Conditions:1. Randomization 2. Population ≥ 10n 3. Normal population or n ≥ 30

Checked:1. Sample is representative of population 2. n = 102 102 X 10 = 1020 There are more than

1,020 food items in Wegmans3. n = 102 ≥ 30

1 SAMPLE T-TEST: SODIUM CONT.

All conditions met, Student’s t distribution, 1 Sample t-test

Mechanics: t = = 149.199 – 142.93 = 0.3458 18.1278 P (t < 0.3458│df = 101) = 0.63 k

Conclusions: We fail to reject the Ho because p-value of 0.63

is greater than alpha equal to 0.05. We have sufficient evidence that the true

average sodium content in Wegmans food items per serving is equal to 142.9303 milligrams.

VITAMIN A (INTERNATIONAL UNITS) PER SERVING VS. FREQUENCY OF VITAMIN A IN SAMPLE HISTOGRAM

20

40

60

80

100

Vitamin_A_

0 20 40 60 80 100 120 140

Collection 1 Histogram Right skewed Unimodal Mean is 3.53922 international

units, which is low Vitamin A content

Range is from 0 to 120 international units, which means some items have a low Vitamin A content and some have a high Vitamin A content

There are possible outliers at 40-50, 80-90, and 110-120 international units

A lot of items we sampled have between 0 to 20 international units of Vitamin A in them, which means the items have a low content of Vitamin C

1 SAMPLE T-TEST: VITAMIN A

Hypothesis: Ho: µ = 4.9715 (units) Ha: µ > 4.9715 (units)

Conditions:1. Randomization 2. Population ≥ 10n 3. Normal population or n ≥ 30

Checked:1. Sample is representative of population 2. n = 102 102 X 10 = 1020 There are more than

1,020 food items in Wegmans3. n = 102 ≥ 30

1 SAMPLE T-TEST: VITAMIN A CONT.

All conditions met, Student’s t distribution, 1 Sample t-test

Mechanics: t = = 3.53922 – 4.9715 = -1.024 1.39922 P (t > -1.024│df = 101) = 0.85 k

Conclusions: We fail to reject the Ho because the p-value of

0.85 is greater than the alpha equal to 0.05. We have sufficient evidence the true average

Vitamin A content in Wegmans food items per serving is equal to 4.9715 units.

APPLICATION TO POPULATION

From the 1 Sample t-tests we can conclude that the average Wegmans food item per serving contains... the total fat RDI the sodium RDI the Vitamin A RDI

The average Wegmans product does contain enough nutrition, as measured by total fat, sodium, and Vitamin A, to meet the FDA’s RDI values

Wegmans is selling products that support good health to their customers

BIAS/ERROR The online list of products might not be

representative of the entire store Online list might have online-only products and

stores might have location-specific products People do not necessarily eat according to serving

sizes When people are grocery shopping they do not buy

random items Some foods might not be properly categorized RDI values are for people ages 4 and up

Baby items should not have been included, so the sampling frame should have been different

Spices and water should not have not been included in the sampling frame because they are not considered a nutritional serving

Some nutritional values might not be labeled

PERSONAL OPINIONS/CONCLUSIONS Picking a topic that was interesting and meaningful

made this project easier Finding the samples took 8 hours because the

website takes a long time to load, is difficult to navigate, and is not meant to use for sampling purposes

We were surprised to find that our sampling data did meet the RDI values We thought the food would contain more fat and sodium

and less Vitamin A We were surprised that the majority of our samples

were foods we actually heard of People don’t eat based on a stratified sample; their

diets are strongly biased If people ate our stratified sample, they would be

healthier Food is only one of many factors affecting health

QUESTION AND ANSWER SESSION

Do you believe the food you eat meets RDI values?

Should companies be required to tell people more about their food or should consumers be held responsible for what they eat?

GUESS THE NUTRITIONAL INFORMATION!

What is the total fat in grams for a 1 oz. bag of Lay’s Potato Chips, Classic?

A. 1 gramB. 5 gramsC. 10 grams D. 14 grams

Answer: The total fat is C. 10 grams, which is 16% of your RDI value for total fat

GUESS THE NUTRITIONAL INFORMATION!

What is the sodium content in milligrams for a serving of 0.5 cup of Campbell’s Condensed Chicken Noodle Soup?

A. 700 milligramsB. 800 milligramsC. 880 milligramsD. 890 milligrams

Answer: The sodium content is D. 890 milligrams, which is 37% of your RDI for sodium

GUESS THE NUTRITIONAL INFORMATION!

What is the Vitamin A content for 1 large, raw (8 oz.) Granny Smith Apple?

A. 2%B. 5%C. 10%D. 13%

Answer: The Vitamin A content is A. 2%, which is 2% of your RDI for Vitamin A

GUESS THE NUTRITIONAL INFORMATION! CHALLENGE QUESTION!

What is the calorie content for 2 tablespoons of Baba Ghanouj?

A. 110 caloriesB. 120 caloriesC. 150 caloriesD. 200 calories

Answer: The calorie content is A. 110 calories, which is 4% of your RDI for calories