Presentation on theme: "Fats (lipids) are a class of nutrients. Fats are solid at room temperature (animals) Oils are liquid at room temperature(plants) Monomer is fatty acid."— Presentation transcript:
Fats (lipids) are a class of nutrients. Fats are solid at room temperature (animals) Oils are liquid at room temperature(plants) Monomer is fatty acid = glycerol (alcohol) + Fatty acid (w/a Carboxyl group) Lipids are made of the elements C,H,O Lipids are organic molecules Lipids are macronutrients ---continued--- FATS 101
Fats include: 1.Triglycerides (what we see as fat in our food) are classified as saturated and unsaturated. 2.Sterols (including cholesterol) – not essential 3.Phospholipids (example, lecithin) – not essential FATS 101 CONTINUED
Major source of energy for the body (measured as Calories): Energy dense (9 kcal /g). More than 2x the energy in carbs (4 kcal /g) or protein (4 kcal /g). When eaten in moderation, fat is important for proper growth, development, and maintenance of good health. Insulation Protection Aids in the absorption of vitamins A, D, E, and K. As a food ingredient, fat provides taste, consistency, and stability and helps you feel full. WHY DO WE NEED FATS?
“Low fat” < 3 gm of fat/serving “Reduced fat” or “Less fat” > 25% less fat than reference food “Fat free” < 0.5 gm of fat/serving REDUCE FAT LABELS
Olestra (Olean) Engineered fat Fatty acids linked to sucrose Not digested by enzymes or bacteria Yields no calories Addition of fat soluble vitamins to structure Over-consumption may cause cramping and loose stool May bind to carotenoids in the meal FAT SUBSTITUTES
Symptoms take years to develop Plaque build-up can begin in childhood Myocardial infarction (heart attack) Stroke CORONARY HEART DISEASE
FUNCTIONS OF CHOLESTEROL Essential component of cell membrane Produced by the liver Found only in animal products Forms important hormones Estrogen, testosterone, vitamin D
“Bad” cholesterol WBC remove (oxidize) LDL from circulation Can cause a build-up (plaque) on walls of the blood vessels Leads to atherosclerosis Causes: smoking, diabetes, LDL LDL – LOW DENSITY LIPOPROTEIN
“Good” cholesterol Synthesized by liver and intestine High proportion of protein Picks up cholesterol from dying cells and other sources Levels are raised with exercise Remove cholesterol from the blood stream Pre-menopausal women have higher HDL Reduce risk of heart disease HDL – HIGH DENSITY LIPOPROTEIN
The difference between saturated and unsaturated fat is the amount of hydrogen they contain. All fats contain carbon, hydrogen and a little oxygen. If the fatty acids (subunits of lipids or fats) contain all the hydrogen possible, they are said to be saturated. If not completely full of hydrogen, fatty acids are termed unsaturated. SATURATED VS. UNSATURATED FATS
Unsaturated fat molecules are a curved molecule with negative charges that repel each other so they don't stick together Because these molecules don't stick together, they flow - both in the food and in the arteries. The molecules of a saturated fat are flat. They pile up like pages in a book and stick to each other. They don’t flow and cause blockages. SATURATED VS. UNSATURATED FATS
Solid at room temperature Raise blood cholesterol Animal fats are mostly saturated, such as the fat in milk and dairy products and in meats. Found in tropical oils (coconut oil, palm oil, and cocoa butter) Recommendation: No more than 10% of daily calorie needs SATURATED FATS
Liquid at room temperature Found in vegetable oils (canola, olive, and peanut oils) Eating foods high in monounsaturated fatty acids may help lower LDL cholesterol levels, keep HDL cholesterol levels high, and decrease your risk of heart disease. Recommendation: Up to 20% of daily calorie needs MONOUNSATURATED FATS
Liquid at room temperature Found mainly in vegetable oils (safflower, sunflower, and corn Main fats found in seafood Eating polyunsaturated fats in place of saturated fats decreases LDL (bad) cholesterol but also decreases HDL (good) cholesterol. Recommendation: No more than 10% of daily calorie needs POLYUNSATURATED FATS
Zapping an unsaturated oil with high pressure hydrogen can turn the oil into saturated fat. This hydrogenation process is how vegetable oil is turned into margarine. Hydrogenated fats have two major economic advantages over natural saturated fats. 1.They are cheaper 2.They have a longer shelf life HYDROGENATION
A trans fat is made when manufacturers hydrogenate vegetable oil Trans fat, like saturated fat and dietary cholesterol, raises the LDL cholesterol that increases your risk for CHD. Trans fats interfere with the ability of the cells of the body to metabolize the fats that are good for you. This may damage cell membranes of vital structures, such as the brain and nerve cells. WHAT ARE TRANS FATS?
Trans fat can be found in vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils. A small amount of trans fat is found naturally, primarily in dairy products, some meat, and other animal-based foods. Beginning in January 2006, trans fats were required to be labeled on foods that contain them. WHERE ARE TRANS FATS FOUND?