2. Fat Stats in American Food
- typical American diet ⇒ 34% of calories from fat.
- Some of the fats we eat are visible, but others are less obvious.
- The sources of fat in the American diet have changed over the
past 40 years.
- Americans have reduced their intake of eggs, red meat, whole
milk, and butter but have increased the amount of fat they
consume from pizza, pasta dishes, snack foods, and fast food,
3. Balance and moderation is the key
- Too much of the wrong types
of fat increases the risk of
chronic disease.
- A healthy diet includes the
right kinds of fats along with
plenty of whole grains, fruits,
and vegetables.
4. What is a Lipid?
In order to understand what a triglyceride is, we
have to understand what a lipid first.
Lipid: a diverse group of organic compounds,
most of which do not dissolve in water. Don’t
dissolve in water.
- Function: add calories, texture, and flavor to
our foods. Insulation in the body.
- 4 types of lipids: Triglycerides, fatty acids,
phosphoglycerides (phospholipids), and
sterols.
- Unsaturated (healthier) and saturated (not as
5. Types of Lipids
- Triglycerides: commonly referred to as fat, are the most abundant lipid in our
diet and our bodies.
- Fatty acids: made up of a carbon chain with an acid group at one end. The
more saturated it is with the element hydrogen, the less health properties it has.
- Phosphoglycerides: a type of phospholipid. In organic chemistry, it has a
backbone of glycerol, two fatty acids, and a phosphate group. Phosphoglycerides
allow water and oil to mix. Used as emulsifiers in the food industry and are an
important component of cell membranes and lipoproteins.
- Sterols: made up of multiple chemical rings. The best known sterol is
cholesterol. Cholesterol is made by the body and consumed in animal foods in
the diet. In the body, it is a component of cell membranes and is used to
6. Lipids in the Digestive Tract ⇒ Triglycerides
- Some triglyceride digestion begins in the stomach due to the
action of gastric lipase
- In the small intestine, muscular churning mixes chyme with
bile from the gallbladder to break fat into small globules.
This allows pancreatic lipase (an enzyme) to access these
fats for digestion.
7. Functions of Dietary Fats (primarily Triglycerides) in
Body
- Dietary fat is needed for the absorption of fat-soluble vitamins and to
provide essential fatty acids.
- In the body, triglycerides in adipose tissue provide a concentrated
source of energy and insulate the body against shock and temperature
changes.
- Oils lubricate body surfaces.
- Triglycerides provide a concentrated source of energy in the body.
- Throughout the day triglycerides are continuously stored in adipose
8. Fats/Lipids and Health in general
- Fat contains 9 kcalories per gram.
- A high-fat diet therefore increases the likelihood of weight gain, but it is not the
primary cause of obesity.
- Consuming more energy than expended leads to weight gain regardless of
whether the energy is from fat, carbohydrate, or protein.
- Diets high in fat are associated with an increased incidence of certain types of
cancer.
- In some types of cancer, such as breast cancer, fat may act as a tumor
promoter, increasing the rate of tumor growth.
9. Heart disease (Cardiovascular disease) and dietary fats
- According to MayoClinic.org, heart disease is defined as: conditions
that involve narrowed or blocked blood vessels that can lead to a heart
attack, chest pain (angina) or stroke. Other heart conditions, such as
those that affect your heart's muscle, valves or rhythm, also are
considered forms of heart disease.
- High blood levels of total and LDL cholesterol are a risk factor for
heart disease.
- High blood HDL cholesterol protects against heart disease.
- The risk of heart disease is also increased by diabetes, high blood
pressure, and obesity.
10. Heart disease (cont’d)
- Diets high in saturated fat, trans fatty acids, and cholesterol increase the risk of heart
disease.
- Diets high in omega-6 and omega-3 polyunsaturated fatty acids, monounsaturated fatty
acids, certain B vitamins, and plant foods containing fiber, antioxidants, and
phytochemicals reduce the risk of heart disease.
- The total dietary and lifestyle pattern is more important than any individual dietary factor
in reducing heart disease risk.
11. What is it called when you have a high amount of triglycerides?
- It is called Hypertriglyceridemia ⇒ Defined as high (hyper-) blood levels (-
emia) of triglycerides, the most abundant fatty molecule in your body
- No symptoms are present, although high levels may be associated with skin
lesions known as xanthomas.
- Your body uses triglycerides for energy
- You need some triglycerides for good health. But high triglycerides
might raise your risk of heart disease and may be a sign of metabolic
syndrome. ⇒ In high levels of triglycerides in the bloodstream have been linked to atherosclerosis and,
by extension, the risk of heart disease and stroke.
- Causes: Obesity, poorly controlled diabetes, hypothyroidism, kidney
disease. Consuming high-refined carbs, regularly eating more calories than
12. Treatment of Hypertriglyceridemia
- Weight loss and dietary modification may improve hypertriglyceridemia.
- Lose weight and stay at a healthy weight.
- Limit fats and sugars in your diet.
- Be more active.
- Quit smoking.
- Limit alcohol.
13. How much fat do I need to eat? And what kinds?
- The Dietary Guidelines recommend that total fat account for no more than 30% of
energy, that saturated fat account for no more than 10% of energy, and that dietary
cholesterol be no more than 300 mg per day.
- To keep the amount and type of fat in the diet healthy added fats, protein sources, and
processed foods must be chosen carefully.
- Following the MyPlate recommendations to choose liquid oils rather than solid fats
will help provide a healthy amount and ratio of essential fatty acids.
- Limiting animal fats from the protein and dairy groups reduces saturated fat intake.
- Choosing fish increases intake of omega-3 fatty acids. Eating nuts and seeds
increase both monounsaturated fats and omega-3 fatty acids.
14. How much food do I need to eat? (cont’d) --Low fat foods
- Low-fat foods are made by removing the fat or by including
fat replacers, which simulate the taste and texture of fats.
- Some fat replacers are made by using mixtures of
carbohydrates or proteins to simulate the properties of fat,
and some use lipids that are modified to reduce absorption.
- Low-fat foods and products containing fat replacers can help
reduce fat and energy intake when used in moderation as
part of a balanced diet.
