Exam 2: Chapter 4 Lipids

Triglycerides

The most common type of fat in the body, composed of three fatty acids attached to a glycerol backbone.

Saturated fatty acids

A fatty acid with no double bonds between carbon atoms, meaning it is fully saturated with hydrogen. Found in animal fats, butter, and coconut oil.

Unsaturated fatty acids

A fatty acid that contains one or more double bonds, making it liquid at room temperature. Found in plant oils, nuts, and seeds.

Monounsaturated fatty acid (MUFA)

A fatty acid with one double bond, found in olive oil, avocados, and nuts.

Polyunsaturated fatty acid (PUFA)

A fatty acid with two or more double bonds, found in vegetable oils, fish, and flaxseeds.

Trans fatty acids

Unsaturated fats that have been artificially hydrogenated to be more solid and stable. Found in some processed foods and linked to heart disease.

Essential fatty acids

Fatty acids that the body cannot produce and must be obtained from the diet. Includes linoleic acid and linolenic acid.

Linoleic acid

An omega-6 acid found in vegetable oils, nuts, and seeds. Important for cell function and inflammation regulation.

Linolenic acid

An omega-3 acid found in flaxseeds, walnuts, and fatty fish. Supports heart and brain health.

What are the roles of lipids in the body?

• Provide energy

• Store energy in adipose tissue

• Insulate and protect organs

• Help absorb fat-soluble vitamins (A, D, E, K)

• Serve as structural components of cell membranes

What type of lipid is the major fat found in foods and the body? What are they composed of?

Triglycerides are the major fat found in foods and the body. They are composed of three fatty acids attached to a glycerol backbone.

What are the three types of fatty acids?

1. Saturated fatty acids—No double bonds, solid at room temperature (butter, coconut oil).

2. Monounsaturated fatty acids (MUFA)—One double bond (olive oil, avocadoes).

3. Polyunsaturated fatty acids (PUFA)—Two or more double bonds (vegetable oils, fatty fish).

Where is the cholesterol synthesized?

In the liver.

What are the food sources of cholesterol, monounsaturated fatty acids, and trans fatty acids?

1. Cholesterol—Animal products (eggs, meat, dairy).

2. Monounsaturated FAs—Olive oil, avocadoes, nuts.

3. Trans FAs—Some processed and fried foods, margarine, partially hydrogenated oils.

Which types of fatty acids should be replaced to prevent heart disease?

Saturated fats and trans fats should be replaced with unsaturated fats (especially monounsaturated and polyunsaturated fats).

What is the AMDR for fat, and how do you calculate it?

• AMDR for fat is 20-35% of total daily calories.

• To calculate, multiple total calorie intake by 0.20 and 0.35, then divide by 9 (since fat provides 9 kcal/g).

What is the American Heart Association (AHA) weekly recommendation for fish?

At least 2 servings (3.5 oz per serving) or about 7 oz per week.

How much energy does fat provide, and how do you calculate kcals from fat?

• Fat provides 9 kcal per gram.

• Multiply grams of fat by 9 to get total kcal from fat.

Which fats in the diet should you reduce?

Saturated fats and trans fats should be reduced to lower the risk of heart disease.

What fat is the richest source of saturated fatty acids?

Coconut oil has the highest percentage of saturated fatty acids.