Test points to 'hidden' fat risk

Women with fat around organs in the abdomen were at highest risk

A test has been designed which can show if people of normal weight are at an increased risk of heart disease because they are carrying "hidden" fat.

Developed by South Korean researchers, it checks blood-flow via a cuff on the ankle or arm.

Writing in Clinical Endocrinology, the team say those with the poorest blood flow had more fat around their organs, and so were most at risk.

UK experts said the study reinforced the dangers of abdominal fat.

Good heart health seems to depend more on our shape than our weight. Professor Peter Weissberg, British Heart Foundation

The test measures the flexibility of someone's artery walls. The more elastic they are, the better a person's circulation will be.

The researchers from the University of South Korea tested 150 women aged 22 to 67, who all had healthy lifestyles.

The women's weight was checked.

The researchers then also checked for visceral fat, which lies around the organs and which differs from the ordinary fat which lies underneath the skin, using both the cuff test and body scans - to double-check the results.

People can have too much visceral fat but still be a normal body weight.

Approximately 40% of people are thought to have too much visceral fat stored round their abdominal organs - the key area of concern.

Early detection

The team found normal weight women who had high visceral fat levels scored 11% higher on the test than women who were overweight with normal visceral fat levels.

This suggests the normal weight women had a higher risk of heart disease.

The researchers say other methods of measuring visceral fat levels and the risk of heart disease have been expensive and time-consuming, and that the cuff test could offer a way of diagnosing those at risk early.

And they say identifying those at risk early means they could be encouraged to change their lifestyles to improve their health.

Professor Duk-Chul Lee, who led the research, said: "While having lots of fat around your organs is bad for your health, people can easily reduce their visceral fat levels by taking regular exercise.

"It is essential that people realise the importance of maintaining a healthy lifestyle as well as a healthy body weight."

'Middle-aged spread'

Professor Paul Stewart, an obesity specialist at the Queen Elizabeth Hospital in Birmingham, said: "The take-home message of this study is that having more fat around your the belly area puts you at increased risk of heart disease.

"it's not so much about general obesity; it's about middle-aged spread and where fat lies that's the problem.

"This is one more test that can indicate risk."

Professor Peter Weissberg, medical director of the British Heart Foundation (BHF), said: "This study confirms what we have known for some time; good heart health seems to depend more on our shape than our weight. "

''Visceral' fat inside our abdominal cavity - surrounding our intestines - increases our heart disease risk more than fatness in other parts of our body. "It's possible in future that measures of waist circumference will be included to refine the heart disease risk assessment.

"But factors such as blood pressure, cholesterol and smoking - which are routinely taken into account - are more important."

Retailers to stop trans-fat use

Some margarines contain trans-fats

Major UK retailers plan to stop adding harmful trans-fats to their own-brand products by the end of the year. Trans fats at Wikipedia.

The move was announced by British Retail Consortium members Asda, Boots, Co-op, Iceland, Marks and Spencer, Sainsbury's, Tesco and Waitrose.

It is hoped the move could help cut rates of heart disease and obesity.

reposted from: http://news.bbc.co.uk/1/hi/health/6314753.stm
my highlights / edits

Cholesterol-raising trans-fats, in the form of hydrogenated oils, are often added to bakery and dairy products to extend shelf-life and improve texture.

TRANS-FATS They are partially hydrogenated vegetable oils, turning oily foods into semi-solid foods Used to extend shelf life of products Put into pastries, cakes, margarine and some fast foods Can raise levels of "bad" cholesterol Even a small reduction in consumption can cut heart disease They have no nutritional benefit

They are also used by the fast-food industry.

But they have no nutritional value, and like saturated fats, they raise blood cholesterol levels which increase the risk of coronary heart disease.

Health authorities around the world have recommended their consumption be slashed.

A BRC spokesman said about 5,000 own-brand products would be affected by the decision.

'Major change'

He said it took time to remove the fats, as retailers had to ensure their products remained appealing to consumers in their re-formulated form.

Several leading retailers have already committed to reducing trans-fat levels, but the latest announcement represents a marked acceleration of the process.

Andrew Opie, BRC food policy director, said the decision by its leading members showed that they were prepared to act to achieve major change must faster than any legislation could do.

He said: "This is the latest in a string of healthy food initiatives and shows that BRC members, responding to customer concerns, are willingly delivering a scale and pace of change way beyond anything retailers or manufacturers are doing anywhere else in Europe."

Alex Callaghan, of the British Heart Foundation, said: "It's good to see companies making moves towards reducing and removing trans-fats from their own-brand products.

"Currently, it isn't easy for shoppers to know how much trans-fats are in the food they eat, and it can be confusing.

"The BHF calls for manufacturers and retailers to work towards elimination of trans-fats from products.

"In the meantime, trans-fats should be clearly labelled food packaging so that people can make informed decisions about their diet."

In Denmark, trans-fats in the form of partially hydrogenated oils were effectively banned four years ago.

The European Union is encouraging retailers to reduce or stop adding trans-fats.

However, it is also taking action against the Danish authorities, on the grounds that their ban is a block on free trade with other member states.

Chemically, trans fats are made of the same building blocks as non-trans fats, but have a different shape. In trans fat molecules, the double bonds between carbon atoms (characteristic of all unsaturated fats) are in the trans rather than the cis configuration, resulting in a straighter, rather than a kinked shape. As a result, trans fats are less fluid and have a higher melting point than the corresponding cis fats. (source: Wikipedia)

Body fat percentage (wiki)

Body fat percentage is the fraction of the total body mass that is adipose tissue, as opposed to lean body mass (muscle, bone, organ tissue, blood, and everything else). This index is often used as a means to monitor progress during a diet or as a measure of physical fitness for certain sports, such as body building. It is more accurate as a measure of excess body weight than body mass index (BMI) since it takes into account muscle mass and frame size. However, its popularity is less than BMI because most of the techniques used to measure body fat percentage require equipment and skills that are not readily available.

Total body fat percentage consists of essential fat and storage fat. Essential fat is that amount necessary for maintenance of life and reproductive functions. The percentage for women is greater than that for men, due to the demands of childbearing and other hormonal functions. Essential fat is 2-5% in men, and 10-13% in women. Storage fat consists of fat accumulation in adipose tissue, part of which protects internal organs in the chest and abdomen. Again, women have slightly more than men. The minimum recommended total body fat percentage exceeds the essential fat percentage value reported above.[1]

Recommendations

Some body fat percentage levels are more culturally valued than others, and some are related to better health or improved athletic performance.

According to Thomas A. Owens, M.D. (Departments of Internal Medicine and Pediatrics, Duke University Medical Center, Durham, NC), body fat percentage is categorized as follows:^[1] :

Description	Women	Men
Recommended amount	20-21%	13-17%
Adults in United States, average	22- 25%	17-19%
Obese	30%+	25%+

According to Health Check Systems^[2], The American Council on Exercise^[3] has categorized ranges of body fat percentages as follows:

Description	Women	Men
Essential fat	10-12%	2-4%
Athletes	14–20%	6–13%
Fitness	21–24%	14–17%
Acceptable	25–31%	18–25%
Obese	32%+	25%+

Measurement techniques

A person's exact body fat percentage generally cannot be determined, but there are several different ways we can estimate it, each with varying degrees of accuracy.

Dual energy X-ray absorptiometry

Dual energy X-ray absorptiometry, or DXA (formerly DEXA), is a good method for estimating body fat percentage.

There are several more complicated procedures that more accurately determine body fat percentage. Some, referred to as multicompartment models, can include DXA measurement of bone, plus independent measures of body water (using the dilution principle with isotopically labeled water) and body volume (either by water displacement or air plethsmography). Various other components may be independently measures, such as total body potassium.

In addition, the most refined method, in-vivo neutron activation, can quantify all the elements of the body and use mathematical relations among the measured elements in the different components of the body (fat, water, protein, etc.) to develop simultaneous equations to estimate total body composition, including body fat. This is the most accurate method. You can also use many other methods to calculate body fat percentage/

Body Average Density Measurement (Hydrostatic Weighing)

Prior to the adoption of DXA, the most accurate method of estimating body fat percentage was to weigh a person underwater in order to obtain the average density (mass per unit volume). Since fat tissue has a lower density than muscles and bones, it is possible to estimate the fat content. This estimate is distorted by the fact that muscles and bones have different densities: for a person with a more-than-average amount of bone tissue, the estimate will be too low. However, this method gives highly reproducible results for individual persons (± 1%), unlike the methods discussed below, which can have an error up to ±10%.^[5] The body fat percentage is commonly calculated from one of two formulas:

• Brozek formula: BF = (4.57/ρ − 4.142) × 100
• Siri formula is: BF = (4.95/ρ − 4.50) × 100

In these formulas, ρ is the body density in kg/L.

where ρ_w is the density of water [0.99780 kg/L at 22 °C (72 °F)]. For example, a person weighing 80 kg needs to hold a floater with a volume of 4.5 L and a mass of 0.5 kg has a density of 1.05 kg/L and hence a body fat percentage of 21%. Note that both the Brozek and Siri formulas are claimed to give systematically too high body fat percentages. ^[6]

Bioelectrical Impedance Analysis

The Bioelectrical impedance analysis (BIA) method is more affordable but less accurate way to estimate body fat percentage. The general principle behind BIA: two conductors are attached to a person's body and a small electrical charge is sent through the body. The resistance between the conductors will provide a measure of body fat, since the resistance to electricity varies between adipose, muscular and skeletal tissue. Criticism of this methodology is based on where the conductors are placed on the body; typically they are placed on the feet, with the current sent up one leg, across the abdomen and down the other leg. As men and women store fat differently around the abdomen and thigh region, the results can be less accurate as a measure of total body fat percentage. Another variable that can affect the amount of body fat this test measures is the amount of liquid an individual has consumed before the test. As electricity travels more easily through water, a person who has consumed a large amount of water before the test will measure as a lower body fat percentage. Less water will increase the percentage of body fat. Bioelectrical impedence analysis is available in a laboratory, or for home use in the form of body fat scales and hand held body fat analyzers.

Skinfold Measurements

A simpler procedure for estimating body fat is the skinfold test, whereby a pinch of skin is precisely measured by calipers at several standardized points on the body to determine the subcutaneous fat layer thickness. These measurements are converted to an estimated body fat percentage by an equation. It is of utmost importance to test in a precise location with a fixed pressure.

Girth Comparisons

There exist formulae for estimating body fat percentage from an individual's weight and girth measurements. For example, the U.S. Navy Circumference method compares abdomen or waist and hips measurements to neck measurement and height^[7], and other sites claim to estimate one's body fat percentage by a conversion from the body mass index. Unfortunately, these measures are usually inaccurate as a way of determining body composition.

External links

• A Guide to Body Fat Percentage
• Gallagher D, Heymsfield S, Heo M, Jebb S, Murgatroyd P, Sakamoto Y (2000). "Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index.". Am J Clin Nutr 72 (3): 694-701. PMID 10966886.
• Body Composition
• Yuhasz Skinfold Test
• Fat Caliper Measurement Sites

Body Fat Percentage

Many fad diets, with little or no exercise can cause a person to lose as much muscle tissue as fat. What's more...

There is a good chance that this person will return to their pre-diet weight. Only now they gain back more fat and less lean muscle. Essentially , they are the same weight but they now have a higher body fat percentage and less lean muscle mass. The point to remember is...

Weighing scales will not show any of these changes. Measuring your body fat percentage will. Measure it and you can manage it. If you notice you are losing considerable lean tissue mass as well as fat, you can take appropriate steps to adjust your program.

Sam follows a proper exercise and nutrition program. After a month or so of dedication and determination she notices her weight has changed only slightly if at all... Arrgh!

Not getting discouraged Sam has her body fat percentage measured...

Before her program Sam weighed 150lbs with a body fat percentage of 30%. After 6 weeks she weighs 148lbs. But her body fat percentage has dropped to 26%. The result?

Over 6.5lbs of highly-motivating fat loss! And she has gained 4.5lbs of healthy lean muscle. This situation is so common that you should never gauge the success of a weight loss program with the bathroom scales alone.

And it's exactly the same for someone on weight gain program... only in reverse. In this case any additional weight should come from lean muscle mass. No way to tell that with the bathroom scales. Plus, what if you're weight stays the same? Maybe you put on 10lbs of muscle while losing 10lbs of fat.

So what other benefits does knowing your body fat percentage give you? Let's look at the long term picture and consider your...

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General Health and Well Being

It would be easy to slip into all the negative consequences of excess body fat here. But let's stay on a positive track...

Why is calculating your body fat percentage so crucial to general health and successful aging?

Studies are showing that a typical person living in the western world steadily loses muscle and gains fat starting at age 20. What does that mean exactly?

Well, even if this person maintains a steady weight throughout their life there's a good chance their body fat percentage is increasing and their lean tissue mass is decreasing.

Traditionally aging and all it's physical frailties was seen as inevitable. Not any more...

Most gerontologists agree that simple lifestyle changes can have a dramatic effect on the aging process. The loss of functional strength, increase in body fat percentage, decrease in bone density, reduction in flexibility and decline in aerobic power are all under our control.

Measure your body fat percentage regularly and many of the detrimental signs of old age won't quietly creep up on you.

You'll be able to see, first hand, the changes occurring in your body and, if you choose, you can do something about it.

Before we move on to optimum body fat percentages and the very best ways to measure it, there's one more area affected by your body fat percentage...

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Your Ideal Body Fat Percentage

The absolute perfect body fat percentage does NOT exist. Age and gender make a big contribution to the ideal value, but most importantly...

Everyone is an individual. Some people might feel and perform better at a higher or lower body fat percentage than others of the same age and sex. And that's why...

Ranges and guidelines exist. Have a look at the tables below. The first table gives the ideal body fat percentage ranges for the general population. The second table is the average body fat percentage for different athletes. The important thing to remember is...

Anywhere inside the range is good. Staying below the upper limit should be your target but as you'll soon see lower is not necessarily better.

Body Fat Percentage for The Average Population
Age	Up to 30	30-50	50+
Females	14-21%	15-23%	16-25%
Males	9-15%	11-17%	12-19%

>

Average Body Fat Percentage of Athletes
Sport	Male	Female	Sport	Male	Female
Baseball	12-15%	12-18%	Rowing	6-14%	12-18%
Basketball	6-12%	20-27%	Shot Putters	16-20%	20-28%
Body building	5-8%	10-15%	Skiing (X country)	7-12%	16-22%
Cycling	5-15%	15-20%	Sprinters	8-10%	12-20%
Football (Backs)	9-12%	No data	Swimming	9-12%	14-24%
Football (Linemen)	15-19%	No data	Tennis	12-16%	16-24%
Gymnastics	5-12%	10-16%	Triathlon	5-12%	10-15%
High/long Jumpers	7-12%	10-18%	Volleyball	11-14%	16-25%
Ice/field Hockey	8-15%	12-18%	Weightlifters	9-16%	No data
Racquetball	8-13%	15-22%	Wrestlers	5-16%	No data

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Lower is Not Necessarily Better

A certain amount of body fat is vital for the body to function normally and healthy. In fact striving for a body fat percentage that is too low can be dangerous. Here's why...

Measuring your body fat percentage calculates your TOTAL body fat. This total body fat can be split into 2 categories...

Storage Fat -- This consists mainly of fat deposited just under the skin or subcutaneous fat. Storage fat for men and women is fairly similar. For the average man 12% of bodyweight is storage fat and for the average woman 15% of bodyweight is storage fat.

Essential Body Fat -- For the body to function normally and healthily a certain amount of body fat is required. This is called essential fat. For women the average amount of essential fat is 12% of bodyweight and for men it is 3%.

Trying to achieve a body fat percentage that is so low it affects your essential fat stores is NOT good for your health.

Some storage fat is also required for good health. It's used to protect internal organs in the chest and abdomen. So remember...

Aim to stay within the range for age and gender and rest assured you are taking one of the most positive steps to life-long health you can.

Return to Body Fat Percentage Archive