Chapter 5: Lipids
Student Learning Outcomes
1. Understand the common properties of lipids.
2. Describe the structure of the three forms of lipids: triglycerides, phospholipids, and
sterols.
3. Discuss the importance of the essential fatty acids.
4. Identify food sources of saturated, monounsaturated, and polyunsaturated fatty acids;
phospholipids; and sterols.
5. Explain how lipids are digested and absorbed.
6. Name the lipoproteins and classify them according to their functions.
7. Describe the functions of the various forms of lipids in the body.
8. Summarize current recommendation for fat intake.
9. Characterize the relationship between lipids and cardiovascular disease.
Fact Check: Are Eggs Bad for Your Heart?
● While eggs do provide some saturated fat and cholesterol, don’t overlook their many
nutritional benefits!
● Eggs are inexpensive sources of protein. The protein in eggs is of high quality, which
means that it closely matches the amino acid needs of the human body. Eggs also
supply several micronutrients, such as vitamin D and choline, that tend to be low in the
dietary patterns of most Americans.
● Research evidence indicates that eating an average of one whole egg per day (about
seven eggs per week) is reasonable for heart health.
Section 5.1 Concepts: Lipids: What Are They?
1. Name the three forms of lipids.
2. What is the structural difference between saturated and unsaturated fatty acids?
3. What is the structural difference between omega-3 and omega-6 fatty acids?
4. Which two fatty acids are essential?
5. How do triglycerides differ from phospholipids?
6. Are phospholipids and sterols essential in the human dietary pattern? Why or why not?
Lipids: Common Properties
Diverse group of chemical compounds
Main characteristic-lipids do not readily dissolve in water
Yield 9 kcal per gram
Fats (solid) and oils (liquid)
Generic term that includes:
● Triglycerides
● Phospholipids
● Sterols
Fatty Acids and Triglycerides
Tryglycerides: Three fatty avids bonded to glycerol
, Fatty Acids: Long chain of carbons bonded together
● Alpha end (acid group)
● Omega end (methy gtoup)
Saturated Fatty Acids:
● Solid at room temperature
● More precealent in foods of animal origin
Unsaturated Fatty Acids:
● Liquid at room temperature
● More prevalent in foods of plant origin
● Cis and Trans
Essential Fatty Acids
Two fatty acids must be supplied by the diet to maintain health.
● Linoleic acid (an omega-6 fatty acid)
● Alpha-linoleic acid (an omega-3 fatty acid)
Other fatty acids and regulatory compounds can be synthesized from the essential fatty acids.
Essential Fatty Acids Functions
● Form body structures
● Perform important functions for the immune and nervous systems
● Produce regulatory compounds such as eicosanoids and hormones
Triglycerides and Related Compounds
Main form of lipids in foods and the body
● Triglyceride: Glycerol + three fatty acids
● Diglyceride: Glycerol + two fatty acids
● Monoglyceride: Glycerol + one fatty acid
Section 5.2 Concepts: Fats and Oils in Foods
1. Name three foods for which at least 50% of total calories come from fat.
2. List two dietary sources of cholesterol. List two dietary sources of phytosterols.
3. Which types of fat are used as emulsifiers, and what is their function in food?
4. What are some strategies used to produce reduced-fat foods?
5. What is the benefit of storing plant oils in tinted or opaque containers?
Fatty Acids and Triglycerides in Food
Protein Foods Group:
Low-fat: Kidney beans
Medium-fat: Loin and round cuts of beef
High-fat: Nuts, marbled and processed meats
Dairy Food Group:
Low-fat: Skim milk, low-fat yogurt
Medium-fat: Whole milk or yogurt, cheese
Student Learning Outcomes
1. Understand the common properties of lipids.
2. Describe the structure of the three forms of lipids: triglycerides, phospholipids, and
sterols.
3. Discuss the importance of the essential fatty acids.
4. Identify food sources of saturated, monounsaturated, and polyunsaturated fatty acids;
phospholipids; and sterols.
5. Explain how lipids are digested and absorbed.
6. Name the lipoproteins and classify them according to their functions.
7. Describe the functions of the various forms of lipids in the body.
8. Summarize current recommendation for fat intake.
9. Characterize the relationship between lipids and cardiovascular disease.
Fact Check: Are Eggs Bad for Your Heart?
● While eggs do provide some saturated fat and cholesterol, don’t overlook their many
nutritional benefits!
● Eggs are inexpensive sources of protein. The protein in eggs is of high quality, which
means that it closely matches the amino acid needs of the human body. Eggs also
supply several micronutrients, such as vitamin D and choline, that tend to be low in the
dietary patterns of most Americans.
● Research evidence indicates that eating an average of one whole egg per day (about
seven eggs per week) is reasonable for heart health.
Section 5.1 Concepts: Lipids: What Are They?
1. Name the three forms of lipids.
2. What is the structural difference between saturated and unsaturated fatty acids?
3. What is the structural difference between omega-3 and omega-6 fatty acids?
4. Which two fatty acids are essential?
5. How do triglycerides differ from phospholipids?
6. Are phospholipids and sterols essential in the human dietary pattern? Why or why not?
Lipids: Common Properties
Diverse group of chemical compounds
Main characteristic-lipids do not readily dissolve in water
Yield 9 kcal per gram
Fats (solid) and oils (liquid)
Generic term that includes:
● Triglycerides
● Phospholipids
● Sterols
Fatty Acids and Triglycerides
Tryglycerides: Three fatty avids bonded to glycerol
, Fatty Acids: Long chain of carbons bonded together
● Alpha end (acid group)
● Omega end (methy gtoup)
Saturated Fatty Acids:
● Solid at room temperature
● More precealent in foods of animal origin
Unsaturated Fatty Acids:
● Liquid at room temperature
● More prevalent in foods of plant origin
● Cis and Trans
Essential Fatty Acids
Two fatty acids must be supplied by the diet to maintain health.
● Linoleic acid (an omega-6 fatty acid)
● Alpha-linoleic acid (an omega-3 fatty acid)
Other fatty acids and regulatory compounds can be synthesized from the essential fatty acids.
Essential Fatty Acids Functions
● Form body structures
● Perform important functions for the immune and nervous systems
● Produce regulatory compounds such as eicosanoids and hormones
Triglycerides and Related Compounds
Main form of lipids in foods and the body
● Triglyceride: Glycerol + three fatty acids
● Diglyceride: Glycerol + two fatty acids
● Monoglyceride: Glycerol + one fatty acid
Section 5.2 Concepts: Fats and Oils in Foods
1. Name three foods for which at least 50% of total calories come from fat.
2. List two dietary sources of cholesterol. List two dietary sources of phytosterols.
3. Which types of fat are used as emulsifiers, and what is their function in food?
4. What are some strategies used to produce reduced-fat foods?
5. What is the benefit of storing plant oils in tinted or opaque containers?
Fatty Acids and Triglycerides in Food
Protein Foods Group:
Low-fat: Kidney beans
Medium-fat: Loin and round cuts of beef
High-fat: Nuts, marbled and processed meats
Dairy Food Group:
Low-fat: Skim milk, low-fat yogurt
Medium-fat: Whole milk or yogurt, cheese
