Essentials of Nutrition & Diet Therapy - V13 - Lipids

Review of chapter 4, Lipids

How many Kcal/g do you get from lipids?

9 kcal/g

What is the function of fat in Adipose tissue?

Cell membrane structure & Protect organs by helping to regulate temperature

Important functions carried out by food lipids

Support absorption of fat-soluble vitamins, Add to food palatability, Promote satiety.

build up of fatty deposits of intima (interior walls of major arteries) that increase risk of heart attack or stroke

atherosclerosis

Cholesterol is only found in…

animal sources

Fats, oils & related compounds that are insoluble in water & greasy to the touch

Lipid

foods that may appear to be mainly Carbohydrate or Protein but often contain significant amounts of fat.

Hidden fats

common structural units of lipids

Fatty acids

Body lipids are stored in the body as…

adipose tissue

Fatty Acid Chain Length

Ranges from 4-22 Carbons

More difficult to absorb & require a helping carrier to enter lymph then blood

Long-chain Fatty Acid

Soluble in water & can be absorbed directly into the bloodstream

Short & Medium length Fatty acids

Types of fat

monounsaturated, polyunsaturated, saturated

Building blocks of fat

Fatty acids

complexes of fat and protein that carry lipids in plasma

Lipoproteins

2 Essential fatty acid for humans

Linoleic Acid & Alpha-linoleic Acid

Fatty acids that must be supplied in the diet because the body can’t make them

Essential fatty acids

An n-3 polyunsaturated fatty acid found in fish oil that helps lower risk of heart attack or stroke

Eicosapentaenoic Acid (EPA)

Necessary for brain and neural development in infants and helps lower risk of heart attack and stroke in adults

DHA - Docosahexaenoic Acid

Examples of Linoleic Acid

Safflower oil, corn oil, nuts, wheat germ, cottonseed oil

Examples of ALA

Soybean oil, flaxseed oil, Canola oil, walnuts, wheat germ

Examples of fatty acids from fish

Herring, Mackerel, Halibut, Salmon, Canned Tuna

More pro- inflammatory of the Omegas

Omega 6

Anti-inflammatory of the Omegas

Omega 3

When adequate amounts of essential fatty acids are not consumed

Essential Fatty Acid Deficiency

Symptoms of EFA Deficiency

dry scaly skin, liver abnormalities, poor wound healing, growth failure in infants, impaired hearing and vision

Have multiple local hormone-like actions including - regulation of gastric acid secretion, blood platelet aggregation, body temp, and tissue inflammation

Prostaglandins

Made of 3 fatty acids attached to a glycerol base

Triglycerides

Glycerol combined with 1 fatty acid

Monoglyceride

Glycerol combined with 2 fatty acids

Diglyceride

2of the most saturated fats occurring naturally in plant based foods

Coconut oil & palm oil

Naturally occurring Polyunsaturated Fat

Cis Fat

Hydrogenated form of fat that is commercially processed and are injurious to health

Trans fat

Increases LDL and decreases HDL, while disrupting essential fatty acid function in cells

Trans fatty acid

Appropriate Macronutrient Distribution Range (AMDR) for fat

20-35% of total kcals

Excess calories are stored as…

Fat

Role of Cholesterol

Precursor to steroid hormones, Formation of bile acids, Component of brain and neural tissue, component of cell membranes

Because the body can synthesize cholesterol as needed -

No DRI is necessary.

Classes of lipoproteins

Chylomicrons, very low-density lipoproteins (VLDL), Intermediate-density lipoproteins (IDL), Low-density lipoproteins (LDL) and High-density lipoproteins (HDL)

Lipoprotein formed in the intestinal wall after a meal and carry the digested and absorbed fat to the liver for conversion to other lipoproteins

Chylomicrons

Acts as an emulsifier preparing lipids for further digestion

Bile from gallbladder

gastric enzyme specific to lipids

gastric lipase - tributyrinase

enzyme that acts on lecithin and comes from the small intestine

Lecithinase

Molecules in which one of the 3 fatty acids attached to a glycerol base is replaced with a water-soluble phosphate group

Phospholipids

Apolipoprotein are…

proteins that bind to lipids to form lipoproteins

Lecithin

main phospholipid - part of lipoproteins

transport cholesterol from the liver to the tissues, cause build up of fatty plaque in blood vessels

LDL - Low-density lipoprotein

Return cholesterol from the cells to the liver for excretion, slows or prevents progression of atherosclerosis

HDL - High-density lipoprotein

enzyme from the pancreas that breakdown lipids

pancreatic lipase & cholesterol esterase

End product of fat digestion

mostly monoglycerides, some fatty acids and very little glycerol

A type of fat associated with increased risk of heart disease is:

1. Unsaturated fat

2. Saturated fat

3. Polyunsaturated fat

2. Saturated fat

Compared with long chain fatty acids, fatty acids with shorter chains are:

1. More soluble in water

2. Less soluble in water

3. Bind to water

4. Evaporate water

1. more soluble

Very low-fat diets may provide inadequate amounts of:

1. Carbon

2. Bile

3. Glycerol

4. Fatty Acids

4. Fatty Acids

It is desirable to have high blood levels of:

1. HDL

2. LDL

3. VLDL

4. IDL

1. HDL