Intro to Nutrion CH.5 (PT.2)

What memory word can help you remember LDL?

"Lousy" DLs.

What do HDLs carry?

Cholesterol.

Where do HDLs carry cholesterol from?

The cells

Where do HDLs carry cholesterol to?

The liver.

What is HDL commonly called?

"Good cholesterol."

What memory word can help you remember HDL?

 "Healthy" DLs

What is the major difference between LDL and HDL cholesterol transport?

LDL carries cholesterol from the liver to tissues, while HDL carries it from cells back to the liver.

Which lipoprotein carries cholesterol from the liver to tissues?

LDL.

Which lipoprotein carries cholesterol from cells back to the liver?

HDL.

What are the major functions of lipids in the body?

Energy, body structures, metabolism regulation, vitamin absorption, insulation, and organ cushioning.

How do lipids provide energy?

They can be used as a source of energy.

What body structures do lipids help form?

Structures including cell membranes.

How do lipids affect metabolism?

They help regulate metabolism.

What type of vitamins do lipids help the body absorb?

Fat-soluble vitamins.

How do lipids help regulate body temperature?

They provide a layer of insulation.

How do lipids protect major organs?

They help cushion the organs

What do fatty acids provide to the body?

A concentrated source of kilocalories.

Are fatty acids readily available when the body needs energy?

Yes.

What is the body's main source of energy throughout the day?

Fatty acids.

What happens to excess fat in the body?

It is stored.

Where is excess energy from fat primarily stored?

In adipocytes.

What are adipocytes?

Fat cells.

How much can fat cells increase in size?

Up to 1,000 times their original size.

What happens when existing fat stores become filled?

 Additional fat cells are made.

Does the body have a limited or unlimited ability to store excess energy as fat?

An unlimited ability.

Is all fat stored in adipocytes?

No, some fat is also stored in muscle cells.

 Are fats a powerful fuel source?

Yes.

Which organs and tissues prefer fat as a fuel source?

The heart, liver, and resting muscle.

How does using fat for energy help conserve glucose?

 It spares glucose for tissues that depend on it.

Which parts of the body especially need the glucose spared by fat use?

The central nervous system and red blood cells.

What does it mean when fat “spares glucose”?

Fat is used for energy so glucose can be reserved for the central nervous system and red blood cells.

When does fat provide a backup source of energy?

Between meals.

Can fat alone sustain life during prolonged starvation?

No.

Why can't fat alone sustain life during prolonged starvation

Glucose is needed to metabolize fat.

What part of fat can be used to make small amounts of glucose?

The glycerol portion.

How much glucose can the glycerol portion of fat produce?

Small amounts.

Why is some glucose still necessary even when the body has large fat stores?

Glucose is needed to metabolize fat.

What does dietary fat help the body absorb?

Several essential nutrients and lipid compounds.

What essential nutrients and compounds require dietary fat for absorption?

Fat-soluble vitamins, carotenoids, cholesterol, and phospholipids.

What type of vitamins require dietary fat for absorption?

Fat-soluble vitamins.

How much dietary fat per day is needed to stimulate chylomicrons?

20 grams per day.

Why are about 20 grams of dietary fat needed per day?

To stimulate chylomicrons that transport fat-soluble vitamins.

What transports fat-soluble vitamins after dietary fat stimulates their formation?

Chylomicrons.

Where are triglycerides stored in the body?

Adipose tissue.

What does fat in subcutaneous tissue do?

It insulates the body and helps maintain body temperature.

How does subcutaneous fat help regulate body temperature?

It provides insulation.

How does stored fat help protect the body?

It protects bones and vital organs from trauma.

What body structures are protected by stored fat?

Bones and vital organs.

Can too much stored fat be harmful to health?

Yes.

What health conditions are associated with too much stored fat?

Heart disease, hypertension, and diabetes.

What is linoleic acid converted into?

Arachidonic acid.

What does ALA stand for?

Alpha-linolenic acid.

What is alpha-linolenic acid (ALA) converted into?

Eicosapentaenoic acid (EPA).

What can ALA be elongated into?

Docosahexaenoic acid (DHA).

What does EPA stand for?

Eicosapentaenoic acid.

What does DHA stand for?

Docosahexaenoic acid.

What substances are used to make eicosanoids?

EPA and arachidonic acid.

What are eicosanoids?

Hormone-like substances.

What do eicosanoids regulate?

Blood clotting, immune function, inflammation, and blood pressure.

How do eicosanoids affect blood clotting?

They help regulate blood clotting.

How do eicosanoids affect the immune system?

They help regulate immune system activity.

How do eicosanoids affect inflammation?

They help regulate inflammation.

How do eicosanoids affect blood pressure?

They help regulate blood pressure.

What is ALA needed to make?

Healthy cell membranes.

In which tissues is ALA especially important for healthy cell membranes?

Nerve tissues and the retina.

Why is ALA important for nerve tissue and the retina?

It is needed to make healthy cell membranes in these tissues.

What organ uses cholesterol to make hormones, bile, and vitamin D?

The liver.

What does the body use cholesterol as starting material for?

Vitamin D, sex hormones, and bile acid.

What vitamin is made using cholesterol?

Vitamin D.

What sex hormones can be made using cholesterol?

Estrogen and testosterone.

What substance used in digestion is made from cholesterol?

Bile acid.

What two types of lipids are important components of cell membranes?

Phospholipids and cholesterol.

What role do phospholipids have in cell membranes?

They are part of the phospholipid bilayer.

What role does cholesterol have in cell membranes?

It is a structural component.

 About what percentage of total kilocalories do Americans consume from fat?

About 33%.

Besides the amount of fat consumed, what else should be considered?

The type of fat consumed.

What is the AMDR recommendation for total fat intake?

20–35% of daily kilocalories.

Does eating excess fat automatically cause weight gain?

No, not unless excess total kilocalories are consumed.

Why can a high-fat diet make excessive kilocalorie intake more likely?

Fat contains concentrated kilocalories.

How much of total kilocalories should come from saturated fat for heart health?

No more than 10%.

What saturated fat intake is considered ideal for heart health in these notes?

Less than 7% of total kilocalories.

What types of fat should replace saturated fats?

Monounsaturated and polyunsaturated fats.

How much of total kilocalories should come from trans fats?

Less than 1%.

What are the main recommendations for heart-healthy fat intake?

Limit saturated and trans fats and replace saturated fats with monounsaturated and polyunsaturated fats.

What is the AMDR for linoleic acid?

5–10% of total kilocalorie intake.

What is the AMDR for alpha-linolenic acid?

0.6–1.2% of total kilocalorie intake.

How much essential fatty acid should people diagnosed with heart disease consume each day?

1 gram per day.

How much EPA and DHA daily may help reduce blood triglycerides?

2–4 grams per day.

 How much EPA and DHA do Americans currently consume per day?

About 0.1–0.2 grams per day.

How does typical American EPA and DHA intake compare with the 2–4 gram amount that may lower triglycerides?

Typical intake is much lower, at about 0.1–0.2 grams per day.

Is dietary cholesterol essential?

No.

Why is dietary cholesterol not essential?

The liver synthesizes the cholesterol the body needs.

About how much cholesterol does the liver synthesize per day according to these notes?

About 900 mg per day.

How does dietary cholesterol intake affect cholesterol synthesis by the liver?

The liver decreases its cholesterol synthesis as dietary intake increases.

How are total blood cholesterol levels maintained?

By a feedback system.

Are dietary phospholipids essential?

No.

What is the most common dietary phospholipid?

Lecithin.

Does the body need dietary lecithin to meet its needs?

No, the liver makes the phospholipids, including lecithin, that the body needs.

What organ produces the phospholipids the body needs?

The liver.

What happens to lecithin in the GI tract?

It is digested.