FATS - Lipids in Nutrition

Vocabulary flashcards covering the key terms and concepts about fats, lipids, and fat digestion from the lecture notes.

Fats (lipids)

A diverse group of insoluble-in-water nutrients including fats, oils, phospholipids, and sterols that serve as an energy source, part of cell membranes, and signaling molecules.

Triglycerides

The main form of dietary fat; consists of one glycerol backbone with three fatty acid chains.

Saturated fats

Fats with no double bonds in their fatty acids; typically from animal sources and some plant oils; can raise LDL cholesterol.

Sources of saturated fats

Animal products (meat, butter, cheese) and plant oils (coconut oil, palm oil).

LDL cholesterol

Low-density lipoprotein; often called 'bad' cholesterol; high levels can lead to plaque buildup in arteries.

Unsaturated fats

Fats with one or more double bonds in fatty acids; generally liquid at room temperature and heart-healthy.

Monounsaturated fats

Fats with one double bond; sources include olive oil, avocados, and nuts; tend to lower LDL cholesterol.

Sources of MUFAs

Olive oil, avocados, and nuts.

Polyunsaturated fats

Fats with two or more double bonds; include omega-3 and omega-6 fatty acids; essential for the body.

Omega-3 fatty acids

A type of PUFA with anti-inflammatory effects; important for heart and brain health; found in fatty fish, flaxseeds, and walnuts.

A type of PUFA essential for health; found in vegetable oils and nuts; balance with omega-3 is important.

Omega-6 fatty acids

Trans fats

Fats with trans configuration from hydrogenation; raise LDL and lower HDL; associated with higher cardiovascular risk.

Sources of trans fats

Partially hydrogenated oils in processed and fried foods.

Trans fat health implications

Can increase risk of heart disease; recommended to minimize or avoid.

Energy density of fats

Provide about 9 calories per gram, more energy-dense than carbohydrates or proteins.

Cell membrane structure (fats)

Phospholipids and cholesterol are key components that maintain membrane integrity and fluidity.

Hormone production (fats)

Fats are involved in the synthesis of various hormones, including sex and steroid hormones.

Absorption of fat-soluble vitamins

Fats are needed to absorb vitamins A, D, E, and K efficiently.

Insulation and protection

Fat protects organs and helps regulate body temperature via subcutaneous fat.

Essential fatty acids

Omega-3 and omega-6 fatty acids that must be obtained from the diet and support brain and body functions.

Phospholipids

Lipids with a glycerol backbone, two fatty acids, and a phosphate-containing head; form the cell membrane bilayer and are amphipathic.

Sterols

Lipids with a four-ring core; cholesterol is the most well-known sterol and serves as membrane component and hormone/ bile acid precursor.

Cholesterol

A sterol essential for membranes and hormone synthesis; found in animal products and also produced by the body.

Glycolipids

Lipids bound to carbohydrate; involved in cell recognition and communication.

Phosphatidylcholine (PC)

A common phospholipid with a choline head group; major component of cell membranes.

Lipid digestion overview

Fat digestion involves mouth (salivary lipase), stomach (gastric lipase), and small intestine with bile emulsification and pancreatic lipase, producing micelles and fatty acids for absorption.

Micelles

Tiny fat droplets formed after emulsification that transport digested fats to the intestinal enterocytes for absorption.

Chylomicrons

Lipoprotein particles formed in enterocytes to transport absorbed triglycerides through the lymphatic system into the bloodstream.

Lipoprotein lipase

Enzyme on capillary walls that hydrolyzes triglycerides from chylomicrons, releasing fatty acids for tissues.

Food cholesterol vs blood cholesterol

Dietary cholesterol in foods vs cholesterol levels in blood (LDL and HDL); dietary cholesterol impact varies among individuals and is influenced by overall fat intake.

Dietary guidelines for fats

Aim for 20-35% of calories from fat; limit saturated fats to <10%; minimize trans fats; emphasize unsaturated fats.

Dietary fats and heart health

Focus on healthier fats (unsaturated) to support heart health and reduce inflammation; balance fats within a varied diet.