Food Labels and Nutrition Fundamentals

Jan 23, 2014

Bio 28: NutritionInstructor: Paul Nagami

Laney College

Today’s Agenda• Reminders• Three fundamental concepts for the

first half of this course:• Energy and Calories• Matter Conservation and Nutrients• Individual factors

• Dietary allowances• Reading a food label• Wrap-up

Challenge StatementAgree or

disagree and why?

“Calorie count is not a measure of how healthy or unhealthy a food is.”

Fundamental Concept No. 1

Energy cannot be created or destroyed – ever. “Calories in = calories out.” (but that may mislead)

What Is Energy?Energy is the capacity of a system to do work… but what does that mean?

How Do We Measure Energy Content?

Burning food releases energy in the form of heat. We can use a calorimeter to measure this release.

What is a Calorie? 1 calorie =

amount of energy needed to heat up 1 gram of water by 1 degree Celsius.

1 FOOD CALORIE = 1 kcal, or 1000 calories.

Caloric Rules of Thumb

Fat/oil = 9 kcal/g

Protein = 4 kcal/g

Carbs = 4 kcal/g

Alcohol = 7 kcal/g

Fundamental Concept No. 2

In a human body, matter isn’t created or destroyed, but it can be rearranged (metabolism)

Macronutrients and Micronutrients

Macronutrients give us the matter we need to build the body, and the energy to put those pieces of matter together. What are the three macronutrients?

Micronutrients are “helpers” of metabolism, vitamins and minerals.

Fundamental Concept No. 3

Different people have different nutritional needs, and nutrition can’t be studied without context.

People are not test tubes. Many factors affect what people eat!

What factors affect people’s dietary choices? Let’s name some.

Factors in Dietary ChoicesEating environmentCulture and TraditionLikes and DislikesFamilyFinancesConvenienceMedia/AdvertisingAgeHealth Conditions

Nutritional Choices Are ComplexIt isn’t the place of science or this class to tell you which choices to make, but rather to help you make informed choices.

Dietary Guidelines and StandardsAre there any general rules for setting up a healthy diet?Governmental and academic organizations set up dietary guidelines and standards.In the U.S., the idea of a Recommended Dietary Allowance (RDA) goes back to WWII.The RDA is now part of a broader set of standards, the Dietary Reference Intakes (DRIs).

Nutrition Facts labelsMost foods bought at the store are legally required to bear a Nutrition Facts label.% Daily Value:Given for the “average person.” 5% = low20% = high

Balancing Fat, Carbohydrates, and Protein

While there’s some variation between different people’s needs, as a general rule:10 – 35% of Calories from protein20 – 35% of Calories from fat45 – 65% of Calories from carbohydrates

Protein

Fat

Carbo-hydrates

Percentage of Calories

Calculating % of CaloriesTo find the number of Calories from protein……take the grams of protein and multiply by 4 kcal/gram.To find the percentage of Calories from protein, divide this result by the total number of Calories per serving, then multiply by 100%

For carbohydrates, follow the same steps. For fats, multiply by 9 kcal/gram instead of 4.

Food Label Activity!

Review