Outline of this page
There is a lot of information contained on this page. To help you sort through all of it, below is an outline of the page. Each item in the outline links to the relevant part of the page so you can go straight to the section that interests you. Of course, you can also read it from top to bottom!
- Understanding Fat
- What are Fats
- Lipids
- Saturated, Monounsaturated, Polyunsaturated Fatty Acids
- Omega-3, Omega-6, and Omega-9 Fatty Acids
- Fats in the Body
- Digestion and Absorption
- Fat Storage
- Why We Need Fat
- A Fat Virus?
- SAFE Weight loss Supplements
- How Much Fat Should You Eat?
- Good Fats
- The Big Fat Lie
- Good Fats
- Fat Composition of Foods
- Calculating Fat Content of Food
- Body Mass Index -- Introduction
- Body Mass Index Caclulator -- Where are You?
- Diet Do's and Dont's
- Exercise and Fat loss
What are fats?
LIPIDS: Like all nutrients, fat is needed by the body, and is beneficial in appropriate quantities. Although it is true that in our society people are more like to ingest too much fat, ingesting too little is unhealthy. Fats are a subset of the class of compounds called "lipids". Lipids include triglycerides (fats and oils), phospholipids, and sterols. The latter two comprise only about 5 percent of the lipids in the diets. The line on a product's Nutritional Label that says "Total Fat", actually should read "Total Lipids". Although most discussion of fats focusses on the Triglycerides. Triglycerides, as the name indicates, are a combination of three fatty acids attached to a glycerol molecule. A fatty acid is an organic acid. An organic acid consists of a carbon chain with hydrogens attached and with an acid group (COOH) at one end. At the other end of a fatty acid is a methyl group (CH3).
Saturated, Monounsaturated, and Polyunsaturated Fatty Acids
Fatty acids are called "saturated" when they have all the Hydrogen atoms they can hold. They are saturated with Hydrogen. When two Hydrogen atoms are removed from two of the Carbon atoms, those carbon atoms forma double bond, and the resulting fatty acid is called "monounsaturated"; "mono-" because there is one double bond. When more Hydrogen atoms are removed, more double bonds form, and the resulting fatty acid is called "polyunsaturated"; "poly" = "many" double bonds. Most triglycerides are mixed, meaning they contain more than one type of these three fatty acids.
The degree of saturation is interesting because of the health implications. People with heart disease are often told to reduce their intake of saturated fats. Saturated fats stimulate the liver to produce more cholesterol. People whose families have a high incidence of cancer are often told to reduce their intake of polyunsaturated fats as well.
Omega-3, Omega-6, and Omega-9 Fatty Acids
The class of triglycerides known as polyunsaturated fatty acids can further be broken down into 3 families that are of particular importance to nutrition. When counting from the methyl (CH3) end of a polyunsaturated fatty acid, if the first double bond occurs at the third Carbon molecule, this fatty acid is called an "Omega-3 Fatty Acid." If the first double bond occurs at the sixth Carbon, this polyunsaturated fatty acid is called an "Omega-6 Fatty Acid." And, as you probably have deduced by now, if the first double bond appears at the ninth Carbon, it is an "Omega-9".
You have undoubtedly read of the importance of the Omega-3, -6, and -9, fatty acids for the human body. Docosahexaenoic acid (DHA) is an Omega-3 fatty acid that is especially active in the retina of the eye and the cerebral cortex of the brain. Although the body can synthesize DHA, it can only do so slowly, so DHA must be consumed to ensure a healthy quantity present in the body. This example is provided to demonstrate the importance of consuming fat--it does more than just make people fat! Only under a doctor's orders should someone dramatically restrict their fat intake. This is not a licensed to live on bacon double-cheeseburgers, french fries, and sausage pizza! Elsewhere at this site, we discuss "good fats".
Digestion, Absorption, and Storage of Fat
In the mouth , glands at the base of the tongue secrete a lipase. Lipase is an enzyme that hydrolyzes lipids--that is, it breaks lipids into two, adding a hydrogen atom (H) to one, and a Hydrogen peroxide (HO) to the other; the H and HO previously having formed a water molecule. In the stomach, the lingual lipase hydrolyzes one bond of the triglycerides to produce diglycerides and fatty acids. (A diglyceride is a compound formed from two fatty acids.) The degree to which the fats are hydrolyzed is most significant for milk fats. The stomach churns to mix fats with water and acids, and a gastric lipase accesses and hydrolyzes a little fat. In the small intestine, bile from the liver emulsifies fat, and then pancreatic lipase (from the pancreas, of course!) breaks the emulsified fat into monoglycerides, glycerol, and fatty acids which can be absorbed. In the large intestine, some fat and cholesterol is trapped in fiber and exits in feces.
This last statement--some fat and cholesterol are tapped in fiber and exit the body--is the key behind one of the products featured at this site. Chitosan HD® does exactly this--it binds some fat to fiber, never to be digested, absorbed, or stored in the body. Without absorbing the fat, your body never has the opportunity to store it! Below, in the section on why we need fat, you will learn why you don't want to take Fat Absorber before every meal.
Once absorbed, the body transports the lipids with lipoproteins. You have probably heard of lipoproteins in the context of high- and low-density lipoproteins, HDL and LDL. HDL is the so-called "good" cholesterol, and LDL is the "bad" cholesterol. A person's "risk-ratio" for heart disease is the total cholesterol level divided by the high-density lipoproteins. Lipoproteins circulate through the body making their contents available to all the cells, including muscles, the heart, adipose tissue, and the mammary glands. The cells use the triglycerides, cholesterol and phospholipids in the lipoproteins. The latter two are used to produce hormones, to build membrane, and for storage for later use.
STORAGE: It is the presence of the lipids in the bloodstream that allow the adipose cells to absorb and store fat. The adipose cells contain an enzyme on their surface known as lipoprotein lipase (LPL). LPL is of tremendous interest to scientists (and you!) because its activity controls how much fat is stored! People with more active LPL store more fat. Scientists are currently trying to figure out how the activity level of LPL is influenced by heredity, diet, smoking, and exercise. Perhaps of greatest interest is whether it can be regulated.
More on fat storage
Adipose cells always store fat after meals. Fat breakdown and release occurs when the body is in a fasting state. A hormone-sensitive lipase inside the adipose cells receives the signal to breakdown the triglycerides when fuel is needed by other cells. Unfortunately for people trying to lose weight, the body needs some energy from lean tissue (muscle) because the brain requires glucose, which fat cannot supply. Thus, fat is not lost rapidly, even when fasting. However, this makes it clear that the more energy your body uses, the more fat you will lose. And, the energy requirements of your body increase with exercise, which increases your metabolism. Additionally, your body stores what is in short supply. If you do not consume fat, your body will react by storing fat. So, although it may seem counter intuitive, you must consume fat to burn fat; fasting alone--or eliminating fat from your diet--will not do the trick. It is unhealthy and unproductive to eliminate fat from your diet.
Why do we need fat?
Possibly the first reason is that it provides flavor, tenderness and aroma to food. Plus, fat adds satiety to food--try feeling full from eating nothing but rice cakes. You can't do it (nor should you try--remember, you need fat). More importantly than the pleasure we receive from the fat in our foods, there are four vitamins--A, D, E, and K--that are "fat soluble". This means that they "dissolve" in fat; if you don't eat fat, you will not get any of these vitamins unless the food is fortified with them. Skim milk is one such example. When the fat is skimmed off the whole milk to produce skim milk, vitamins A and D are removed. That's why the milk in your refrigerator probably says "Fortified with Vitamins A and D"--the manufacturer adds these vitamins back in to the milk to maintain its nutritional value.
Fat provides energy. One gram of fat provides 9 kilocalories ("Calories"), whereas the same weight of protein or carbohydrates provides only 4 kilocalories. This means that the single most effective way to reduce caloric intake is to reduce fat.
Additionally, a layer of fat beneath the skin provides insulation. A fat pad below the kidneys provides protection and cushioning to help prevent the kidneys from being damaged. Cholesterol forms part of the external and internal membrane that make up cell structure, can be converted to hormones, bile and Vitamin D.
A fat virus?
Recently you may have heard news stories that scientists are currently investigating whether a particular virus may be responsible for weight gain in some individuals. This is only a hunch. Scientists have observed that during the 1980's there was a tremendous increase in the spread of a particular virus. At the same time, Americans gained more weight than any other decade for which there are records. These two observations, happening concurrently, have spurred this investigation. To date there is no scientific causal link. Other factors that occurred in the 1980's, such as the proliferation of "fat-free" foods , and increases in our "modern" lifestyle that frequently means more use of our cars, elevators, stairs, fax machines, and telephones, and less use of our legs, are also correlated with the weight gain era of the 1980's.
Safe Weight loss Supplements:
How much fat should I eat?
30% fat. That's right--well, pretty much. As closely as people are able to monitor their diets on a daily basis, yes, 30% fat. Using precise, and cumbersome, tracking of food intake, 27% fat seems ideal. Most people don't realize it, but without consuming fat, your body actually stores fat. It's not only scientific fact, but it's also common sense--your body stores what is in short supply for as long as it can. Most diet programs emphasize low fat intake; this widespread--but incorrect--belief is so prevalent that a whole industry has sprung up around it! Take a look at the products available on the shelves of your favorite grocery store: notice how prevalent the emphasis is on "low fat" products and you will begin to get a feel for the scope of the situation. Remember one very important thing, 30% fat refers to the percentage calories from fat. One gram of fat provides 9 Calories of energy, compared to 4 provided by one gram of protein or carbohydrates.
The Big FAT Lies
OK, here it is: fat is bad. That's the lie. Now here is the truth: YOU NEED TO EAT FAT; THERE ARE GOOD (AND BAD) FATS. You can safely eat cholesterol. A properly balanced diet has you eating two of the past decades' biggest diet villains--fat and cholesterol. THE TRUTH IS, FAT SLOWS THE ABSORPTION OF CARBOHYDRATES, AND YOUR BRAIN IS COMPOSED LARGELY OF CHOLESTEROL. This means that you can safely go ahead and eat proteins that contain cholesterol (that is why we're afraid of protein-rich foods, isn't it?) and foods that contain fat--but good fats. More information on why we need fats, what fats are, and how our bodies use fats is located in the "Understanding Fat" sections above.
A cautionary note:
Do not use this information to rationalize a high-fat diet. Studies show that when two different diets are compared, one with a higher concentration of fats, but both with identical Calorie content, the high fat diet causes more fat to be deposited in the body tissue. So, eat enough fat, but DO NOT EAT TOO MUCH FAT.
Good Fats
Good fats may reduce or eliminate "cellulite"
Got your attention? It's true, read on... There are good fats and bad fats. While we have provided a list of them for you on our dietary guidelines page, it is worthwhile to understand what they are and why they are good. Look at the following list, taken from Gene and Joyce Daoust's excellent book, 40-30-30 Fat Burning Nutrition. Fat in the diet provides you with:
- Energy
- The release of CCK, a hormone that signals the brain that you're full and to stop eating
- Fat-soluble compounds for proper metabolism of fat-soluble vitamins
- Omega 3 and Omega 6 fatty acids, necessary for fat metabolism and production of eicosanoids
- A control mechanism to slow the rate of carbohydrate into the bloodstream and reduce the rate of insulin secretion
There are three types of fats (again, see the Understanding Fat sections at the top), and you should be eating roughly equal proportions of them all. The three types of fats are saturated, unsaturated, and monounsaturated. The "ideal" 30% dietary intake of fat would then consist of equal parts of each of these fat types. The bad fats--saturated fats, and for some people polyunsaturated fats--are those that are cooked at high temperature, or are hydrogenated oils (hydrogenation, as its name implies, is the process of adding a hydrogen atom to oil to make it a solid, saturated fat). The word "ideal" was set in quotes above because it may vary across persons. In fact, "ideal" may be precisely 27% of caloric intake from fat. A recent scientific study indicated that reducing fat intake 10%--specifically from 30% to 27%--reduced blood cholesterol by 13%. Further reductions below 27% did not further reduce cholesterol levels. To achieve this reduction, reduce saturate fats to about 7% of fat intake. For most people, 30% may be as precise as they can get and still have time to get to work, take care of the kids, mow the lawn, and get a good night's sleep. For those who are able to be exact in their calculations, 27% is the number to achieve.
Calculating fat content of food
The percentage of Calories from fat in a given food, can be calculated as follows:
(Fat grams x 9) ÷ Total Calories * 100 = % Calories from fat.
For example, a McDonald's Big Mac is 562 Calories, and contains 32 grams of fat.
(32 * 9) ÷ 562 * 100 = 51.2% of Calories from fat.
Is that simple(and can be that alarming!).
Body Mass Index
Are you "Marginally Overweight"? "Overweight"? Obese?
The following information is based on the Body Mass Index concept. This index is the ratio of a person's weight divided by their height squared.
BMI is highly correlated with body fat. This height-weight calculation helps to determine whether you are at a healthy weight or have too much body fat. It is by no means the definitive answer, as it may overstate body fat for those with muscular builds and athletes. But studies have shown that a BMI of 27 or higher is associated with an increased risk of comorbid conditions. These conditions include, but are not limited to, coronary heart disease, certain forms of cancer, stroke, hypertension and noninsulin-dependent diabetes mellitus.
Statistics show that 33% of adult Americans have a BMI of 27 or higher, resulting in over 300,000 lives lost each year due to weight-related illnesses.
According to the National Heart, Lung, and Blood Institute (NHLBI) guidelines, the assessment of "overweight" involves three key measures:
- Body Mass Index (BMI)
- waist circumference
- risk factors for obesity-related diseases and conditions, including:
- high blood pressure
- high LDL cholesterol, low HDL cholesterol, and/or high triglycerides
- sedentary lifestyle
- family history of early heart disease
- family history of certain cancers
- cigarette smoking
Abdominal fat is another predictor of your risk for heart and other diseases, and that is why waist circumference is important. To measure your waist circumference, place a measuring tape snugly around your waist. A waist circumference measurement of over 40 inches in men and over 35 inches in women increases your risk. Obviously this is a rough guideline; a waist circumference of 39 for a 6'6" man is not as "risky" as for a 5'3" man. Always consult your physician for more information regarding reducing your risk for disease.
If you are overweight, the good news is that losing and maintaining as little as 5-10% of initial body weight is likely to result in significant health improvements for you. Lasting weight management can best be achieved by a long-term programs that include increased physical activity, healthy eating, and behavior modification.
Some government agencies and professional health organizations do not agree on the interpretation of results and the weight classifications listed above in the BMI due to its simplistic nature. Always consult your physician for additional information regarding your individual health risks and medical history, and to discuss the limitations of BMI.
Diet Do's and Don'ts
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Shopping
- Shop for food only after eating.
- Shop from a list.
- Avoid prepared foods.
- Take only enough money for your list.
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Rewards
- Plan specific rewards for defined goals and behaviors. Don't make the rewards food.
- Have your family and friends help you achieve your goals. Don't be embarrassed.
- Thank your family and friends for their help; even with gifts.
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Schedule your time
- Plan to limit food intake.
- Substitute exercise for snacking.
- Eat meals and snacks only at scheduled times.
- Don't accept foods offered by others.
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Educate yourself
- Learn nutritional values of foods.
- Decrease your fat intake to reasonable levels.
- Use a diary to identify problems with your diet plan.
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Around the house
- Store food out of sight.
- Eat food in one place only.
- Don't put serving dishes on the table.
- Use smaller dishes and utensils.
- Leave the table immediately after eating.
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Physical Activity
- Increase routine activity.
- Use the stairs.
- Intentionally park you car further from the store entrance instead of seeking out the closest space; or, walk instead of driving.
- Begin a mild exercise plan, such as walking regularly.
- Keep a diary of daily exercise (including routine activities) and gradually increase the exercise.
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Eating Behavior
- Put your fork down between bites.
- Chew thoroughly before swallowing.
- Drink lots of water during the meal.
- Pause in the middle of the meal.
- Do nothing else while eating--don't read or watch t.v.
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Change your thinking
- Avoid unreasonable goals.
- Think of progress, not shortfalls.
- Counter negative thoughts with positive, rational restatements.
- Set realistic weight goals
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Remember, it took years to get fat, You aren't going to get thin overnight.
Exercise and Fat loss
The numbers below are presented as Calories per kilogram of body weight per hour. There are 2.2 pounds per kilogram. To see how this chart applies to you, divide your weight in pounds by 2.2, and multiply that result by the number of Cal/kg/hour for the given activity. This tells how many Calories you will burn in an hour of that activity. Only doing it for 20 minutes? Then multiply that by 1/3 (since 20 minutes is 1/3 of an hour.)
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Activity
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Degree of Activity
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Cal/kg/hour
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Lying down
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Asleep Awake
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0.9 1.1
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Sitting
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Quietly/studying Eating/Writing Driving/Typing Rapidly
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1.2 1.5 2.2
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Standing
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Relaxed Washing Dishes/Ironing
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1.8 2.2
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Walking
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3 Miles per hour vacuuming the floor
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3.3 4.2
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Running
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12 minutes per mile 9 minutes per mile 8 minutes per mile 7 minutes per mile 6
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