Chapter 1

Science & Scope of Nutrition

Key things to look for macronutrients and micronutrients,

calculate kilocalories per gram, Dietary Reference Intake (DRI),

three types of experimental design, reliable sources

  • Poor nutrition during pregnancy affects babies and later life
Nutrition

the study of dietary intake and behavior nutrients. influence on human health.

Nutrients

Chemical substances that provide nourishment essential for growth and development

  • Essential nutrients: nutrients that the body cannot produce in sufficient amounts to meet the body’s needs
  • Non-essential nutrients: nutrients found in food that can be manufactured by the body in sufficient amounts to meet our needs
6 classes of nutrients:

They are required for normal growth, development, reproduction, maintenance, repair of cells, and other vital body processes.

Macronutrients: need in large amounts; all but water provide calories.

  • Carbohydrates
  • Proteins
  • Fats (lipids)
  • Water

Micronutrients: do not provide calories but are critical to body homeostasis and health.

  • Vitamins
  • Minerals

Alcohol is not a nutrient but provides calories.

Phytochemicals are a dietary constituent found in plant foods that are beneficial to human health.

Calculation

Example question on the test: Howmanykcalcomefromcarbsifacandybarhas10gofcarbs?How many kcal come from carbs if a candy bar has 10g of carbs?

4kcal/g → 4kcal/1g = x/10g (solve for x)

4 X 10 = 1x → 40= x

So, there are 40 calories in 10 grams of carbs.

^^*Carbs- 4kcal/g^^

^^*Lipids- 9kcal/g^^

^^*Proteins- 4kcal/g^^

^^*Alcohol- 7kcal/g^^

You go out and have yourself a big meal. Your dinner consists of 60 grams of carbohydrates, 42 grams of protein, 39 grams of fat, and 16 grams of alcohol.

4kcal/g → 4kcal/1g = x/60g = 240

4kcal/g → 4kcal/1g = x/42g = 168

9kcal/g → 9kcal/1g = x/39g = 351

7kcal/g → 7kcal/1g = x/16g = 112

Total: 240+168+351+168+112= 871 calories

You are making a pie that has 3260 total kcalories for the entire pie, 42% of those calories comes from carbs. How many grams of carbs are in the pie?

42%=.42

3260kcal * .42=1369.2 kcal

4kcal/g = 1369.2 kcal/xg

1369.2 /4 = 342.3 g of carbs

You get with a new nutritionist who tells you that your caloric intake of around 1600 kcalories and your macro distribution should be 40% carbs, 30% fats, and the rest from protein

40+30+x=100% x=30

1600*.3=480

480/4= 120 grams of protein

Your frozen pizza says it has 2065 kcal and 30% is from fat. How many grams of fat are in the pizza?

Answer: (30% = 0.3) 2065 X 0.3 = 619 kcal from fat

9kcal/g = 619.5kcal/ x grams

9x= 619.6 (divide both sides by 9 to isolate the x) x= 68.833 grams of fat

You need 2500 kcal/day. 45% carbs 18% fats 37% protein

How many grams of carbs per day?

Kcal from carbs/day → 2500 x .45 = 1125kcal Grams from kcal → 4kcal/g = 1125/x → 4x = 1125 → divide both sides by 4 to isolate x and you get x = 281.25

Energy

the capacity to do work

  • Kilocalorie (kcal) = 1000 calories
  • Calorie = kcal = 1000 calories
  • Kilocalories are often listed as “calories” on food labels
Digestion

Extracts macronutrients, micronutrients, and phytochemicals from food

absorption and utilization by the body

Undernutrition - Nutrient deficiency

Overnutrition - Obesity

Dietary Reference intake (DRI) values :

used to assess and plan the diets of healthy people in the United States and Canada

Acceptable Macronutrient Distribution range (AMDR)

Carbohydrate

45% to 65% total calories

225–325 grams for 2000-calorie diet

Protein

10% to 35% total calories 50–175 grams for 2000-calorie diet Fat

20% to 35% total calories 44–78 grams for 2000-calorie diet

Research studies

  • Hypothesis

  • Experiment 

       - Control group Experimental/treatment group

  • Results

  • Publish 

       -  Peer-reviewed journal
key ideas

To obtain a healthy range of intakes for carbohydrates, protein, and total fat, people with diabetes Follow the AMDR

estimated average requirement (EAR)

recommended dietary allowance (RDA),

adequate intake (AI),

tolerable upper intake level (UL).

establish Acceptable Macronutrient Distribution Ranges (AMDRs)

Estimated Energy Requirements (EERs)

The UL represents the intake amount of a nutrient that should not be exceeded.