Nutrition 1020

organic compounds and soluble in fat

• 1. Triglycerides
• 2. Phospholipids
• 3. Sterols

• Energy Yield: Fats provide 9 Calories/gram.
• – Fats are the only type of lipid that the body can convert to ATP or produce energy from.

– Fats are the most Calorically Dense energy producing nutrient.

Calories yielded per weight of the substance.

– Triglycerides (dietary fats) provide 9 Calories per gram while protein and carbohydrate provide 4 Calories per gram and alcohol provides 7 Calories per gram.

Three fatty acids attached to a glycerol on the end

1. Saturated (SFAs)

2. Monounsaturated (MUFAs)

3. Polyunsaturated (PUFAs)

• Have 0 double bonds between the carbons.

• Are found in animal products, hydrogenated vegetable fats, & tropical oils (palm &coconut oil).

• Are solid at room temperature & unhealthy.

• Have 1 double bond in the carbon chain

• Are healthy

• High levels are in olive oil, canola oil, almonds, & avocado

• Become semisolid when refrigerated

• Are liquid at room temperature

• Have >1 double bond in the carbon chain.

• Some are essential for the body.

• Are found in plant oils like corn,cottonseed, safflower, and sunflower oil.

• Are liquid at room temperature.

• Too much can promote cancer.

• Linoleic Acid & Alpha-Linolenic Acid.

• These EFAs are found in plant oils &plant foods.

Linoleic Acid is an omega 6 fatty acid.

Alpha-linolenic Acid is an omega 3 fatty acid.

• AMDR:
• – 5-10% of Calories from Linoleic Acid

– 0.6-1.2% of Calories from Alpha-linolenic Acid

• • Increases satiety value of a meal.
• • Improves texture, flavor & aroma of food.
• • Required for fat soluble vitamin absorption.
• • Provides the body’s major energy stores.
• • Cushions vital organs.
• • Is an essential structural component of cellmembranes.
• • Provides insulation

• • 20-35% of total dietary Calories should come from fat. This is the AMDR.
• <7% should come from SFA. Limit trans fatty acids.

• All excess Calories consumed whether from carbohydrates, proteins, or fats are converted to fat & stored in fat cells.

• Fat is the storage form of energy in mammals.

• Non-Energy Yield: 0 Calories per gram. Phospholipids are non-caloric lipid substances.

• Sources: Lecithin is found in egg yolk and soy products and is the most common phospholipid consumed in the diet.

1. Phospholipids like lecithin are emulsifiers that allow water soluble & fat soluble substances to mix (like oil &vinegar).

2. Lecithin provides choline which is a component of the neurochemical acetylcholine.

3. Phospholipids are used to make cell membranes.

Cholesterol is the most popular dietary sterol

*Non-Energy Yield: Noncaloric, 0 Calories/gram

1. Exogenous: From outside the body.Cholesterol is made by animals. It is only found in animal foods & byproducts.

2. Endogenous: Made inside the human body.

• Egg yolk provides ~275 mg each.

• Organ meats & crustaceans such as crab, shrimp & lobster provide ~190mg per 3 ounces.

• Much smaller amounts are in the fat portions of animal meats & products like milk.

• Cholesterol is a very important molecule in the body.

• Cholesterol is made inside the human body, primarily in the liver, from SFA.

• Usually about 1 gram (1,000milligrams) of cholesterol per day is produced in the body.

• It is a very waxy substance.

Sex glands: Progesterone, Testosterone, Estrogen. (sex hormones)

Adrenal glands: Cortisol (stress response hormone).

Liver: Bile (cholic acid)---- (Aids in fat digestion).

Skin liver kidney: Vitamin D (Nutrient)

and also Myelin Sheath & Cell membranes.

• Cholesterol can be deposited in the artery walls leading to plaque buildup & heart disease.

• To maintain heart health, the dietary recommendation is to limit intake to< 300 mg/day.

• To improve heart health, limit intake to < 200mg/day.