LAB 4 INVESTIGATING LIPIDS (FATS) IN THE FOOD SUPPLY

Lab 4 Lipids in the Food Supply

HMGT 2460 NUTRITION SCIENCE

LAB 4 INVESTIGATING LIPIDS (FATS) IN THE FOOD SUPPLY

Name

In this exercise you complete Tables 1 & 2 and answer questions 1-10.

The purpose of this exercise is to familiarize you with the National Nutrient Databank for Standard Reference and to explore the fat content of common foods. Of particular interest are those that are offered in versions with differing fat content. This is a free nutrient database that is managed by the US Department of Agriculture. It is a source of information used by food manufacturers in developing Nutrition Facts Labels for their products. Complete Tables 1 & 2 (page 4) and answer questions 1-10 (page 5).

Doing the Math Analysis of data requires that you calculate sums, means, ratios, and percentages. In addition, you often convert data from one unit to another. Understanding how to perform basic math and set up a simple algebraic equation is helpful.

Math Functions Commonly Used in Nutrition

1. Sum Add a series of numbers to get a total.

2. Mean Divide the sum by the number of cases. Similar to an average.

3. Ratio Written as A is to B, or A:B The ratio of cows to horses is 1:3.

4. Percentage Add number of cases meeting a criterion and divide by the total number of cases. To get a percentage (%), multiple results by 100.

Numeric Accuracy The level of accuracy used when estimating portion sizes or nutrient content should be consistent and reasonable. If you observe someone scooping chocolate pudding out of a bowl you describe the portion in whole numbers as “small (1),” medium (2),” “large (3),” or “super (4).” When analyzing the data it’s reasonable to round to the nearest tenth (0.0) decimal point. This allows you to report the mean or average pudding portion as 2.5 or 3.1. This is a useful level of accuracy for decision-making in this case.

When conversion factors are given in the hundredths (0.00) be consistent and report the results of any calculations to the second decimal point. For example: To determine how many grams (g) are in 5 ounces (oz.) multiple 5oz x 28.35 g per oz.(conversion factor) to get 141.75 g. Notice that the answer has the same number of decimal points as the conversion factor. Use this same principle when working with nutrients. Record your answer to the same decimal point that the nutrient recommendation is given.

Setting Up a Simple Algebraic Equation

How many liters are in 1 quart?

1 quart = 32.0 fl. oz.

1 liter = 33.8 fl. oz.

32.0 fl. oz. ÷ 33.8 fl. oz. = 0.95 liter.

Conclusion, a quart is slightly smaller than a liter.

PRACTICE THE MATH!

Table A Three Day Vitamin C Intake of College Students by Gender
Student Code	Gender	Day 1 (mg)	Day 2 (mg)	Day 3 (mg)	Mean (mg/day)
02	Female	45	61	72	178 ÷3 = 59.3
20	Female	93	48	54	195 ÷3 = 65.0
16	Male	87	95	66	248÷3 = 82.7
33	Male	92	89	91	272÷3 = 90.7
71	Male	76	66	37	179÷3 = 59.7

Calculating a Sum

a. How many cases are in the table? Count the number of rows (each row is a case). There are 5 cases.

b. How many students are female? Count the number of cases with “female” in the gender column. There are 2 females.

c. How many students had a mean intake of less than (or the symbol <) 70 mg per day of vitamin C?

d. Count the number of cases with a mean of < 70 mg per day. There are 3 students.

Calculating a Mean

What is the Mean or Average value of vitamin C intake for all students on DAY 1?

Sum all cases for the column labeled “Day 1 (mg)” and divide by the number of cases. Add 45 mg + 93 mg + 87 mg + 92 mg +76 mg to get the sum of 393 mg. Divide the sum by the number of cases or 393 mg ÷5 cases = 78.6 mg.

Calculating a Percentage

What percent of students are females?

Count the number of cases that are female. There are 2 females. Count all the cases. There are 5 cases. Divide female cases by total cases or 2÷5 = 0.40. Multiply by 100 to get 40%.

What percent of male students have a mean vitamin C intake > 80 mg per day?

Count the number of male cases that have a mean vitamin C intake > 80 mg/day. There are 2. Count the number of cases that are male. There are 3. Divide male cases meeting the criterion by total males or 2/3 or 0.67. Multiply by 100 to get 67%.

COMPLETE TABLES 1 & 2. ANSWER QUESTIONS 1-10.

NATIONAL NUTRIENT DATABANK WEB ADDRESS

http://ndb.nal.usda.gov/ndb/search/list

Exercise – Comparing the fat content of regular cookies to low fat cookies.

Step 1: Go to the National Nutrient Databank search page [address above, example below]

Step 2: You can search the cookies either by entering the NDB number or the name of the item. If you enter the name, be careful to do so verbatim. If you enter the food item number you are taken directly to its nutrient analysis page. If you enter the food name, click on it to display its nutrient content.

What You Should See on the Screen

When you have completed Step 2 you should see a screen similar to this one. At the top of the list under “nutrient” are the macronutrients, protein, lipid and carbohydrate. Calories are described as “Energy” and labeled as kcal. These are the same calories that you see on Nutrition Facts Labels.

DO THE MATH!

Complete the following 2 tables BY comparing the regular Pecan Sandies to reduced fat.

USE DATA FOR 2.0 COOKIES (31g) – IN THE COLUMN TO THE RIGHT.

Keebler Sandies Pecan Shortbread Cookies [regular] NDB # 28127

Keebler Sandies Pecan Shortbread Reduced Fat Cookies NDB # 28129

REPORT NUMBERS TO THE SECOND DECIMAL PLACE SUCH AS 12.34 NOT 12.3

Table 1 A Comparison of Regular to Reduced Fat Cookies (Servings size 2 cookies)

Cookie	Energy [kcal]*	Total lipid [g]	Carbohydrate [g]	Sugars [g]	Protein [g]
Sandies regular
Sandies reduced fat

*Note: Energy [kcal] is the notation for Calories

Macronutrients as Sources of Calories

Carbohydrate	4 calories per gram
Protein	4 calories per gram
Fat	9 calories per gram

Calculating Percent of Total Calories

Lipid(Fat) has 9 calories per gram. To determine the number of calories from fat in regular cookies multiply the number in the Total Lipid column by 9. To calculate the percent divide the result (calories in lipid) by the energy (calories) in the cookies and multiply by 100.

Doing the Math for Lipid (Fat)! Calculating a Ratio for Calories

9.83 gram x 9 grams/calorie = 88.47 calories Reduced fat = 151 calories

88.47 calories ÷168 calories = 0.527 Regular = 168 calories

0.527 x 100 = 52.7% Ratio = 151:168

Table 2 Comparison of Regular to Reduced Fat Cookies by Percent of Total Calories

Cookie	Energy [kcal]	% Lipid	% Carbohydrate	% Sugars	% Protein
Sandies shortbread
Sandies reduce fat

Total calories do not include a value for sugars. Sugars are included in carbohydrate.

Total percent may add to slightly more than 100% due to rounding in the database.

ANSWER THESE QUESTIONS

1. Which cookie (regular or reduced fat) has the most calories (energy) per serving?

2. Which cookie (regular or reduced fat) has the most grams of fat (lipid) per serving?

3. A recommended 2000 calorie diet contains 65 grams of fat (lipid). If Andrea ate four (4) regular cookies, what percent of her total daily recommended fat did she consume? Remember to check the number of cookies in per serving.

4. If Andrea ate four (4) reduced fat cookies, what percent of her total daily recommended fat did she consume?

5. Which cookie (regular or reduced fat) has the most grams of carbohydrate per serving?

6. In regular cookies what percent of carbohydrate is provided by sugar?

7. In reduced fat cookies what is the percent of carbohydrate is provided by sugar?

8. A recommended 2000 calorie diet contains 300 gm carbohydrate. If Jay ate six (6) regular cookies, what percent of his total daily recommended carbohydrate would he have consumed?

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10. If Jay ate six (6) reduced fat cookies, what percent of his total daily recommended carbohydrate would he have consumed?

11. Discuss the role of reduced fat cookies in maintaining a healthy weight. Consider calories, lipid (fat), and carbohydrate in framing your answer. Is reducing fat content by increasing carbohydrate content a healthful approach? Explain.

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