Waist to height ratio ‘more accurate than BMI’

Waist to height ratio ‘more accurate than BMI’ – Telegraph.

 Telegraph

Waist to height ratio 'more accurate than BMI'

Keeping your waist circumference to less than half of your height can help prevent the onset of conditions Photo: Alamy

Measuring the ratio of someone’s waist to their height is a better way of predicting their life expectancy than body mass index (BMI), the method widely used by doctors when judging overall health and risk of disease, researchers said.

BMI is calculated as a person’s weight in kilograms divided by the square of their height in metres, but a study found that the simpler measurement of waistline against height produced a more accurate prediction of lifespan.

People with the highest waist-to-height ratio, whose waistlines measured 80 per cent of their height, lived 17 years fewer than average.

Keeping your waist circumference to less than half of your height can help prevent the onset of conditions like stroke, heart disease and diabetes and add years to life, researchers said.

For a 6ft man, this would mean having a waistline smaller than 36in, while a 5ft 4in woman should have a waist size no larger than 32in.

Children in particular could be screened as early as five using the waist-to-height ratio to identify those at greatest risk of obesity and serious health conditions later in life, it was claimed.

Researchers from Oxford Brookes University examined data on patients whose BMI and waist to height ratio were measured in the 1980s.

Twenty years later, death rates among the group were much more closely linked to participants’ earlier waist-to-height ratio than their BMI, suggesting it is a more useful tool for identifying health risks at an early stage.

By comparing the life expectancies of various groups of people at different waist-to-height ratios, they were able to calculate how many years of life were lost as people’s waistlines increased.

For example, a man aged 30 with a waist-to-height ratio of 0.8, representing the largest one in 500 men, stood to lose 16.7 years of life due to their size.

A 50-year-old woman with the same ratio, accounting for about one in 150 women of the same age, would lose 8.2 years of life on average.

Dr Margaret Ashwell, whose previous research has suggested that the waist-to-height ratio could be a better tool than BMI for predicting a range of diseases, presented her findings at the European Congress on Obesity in Liverpool.

Measuring someone’s waist is important because it accounts for levels of central fat which accumulates around the organs and is particularly closely linked to conditons like stroke and heart disease.

She said: “If you are measuring waist-to-height ratio you are getting a much earlier prection that something is going wrong, and then you can do something about it.

“The beauty is that you can do it in centimetres or inches, it doesn’t matter. We have got increasing evidence that this works very well with children as well, because whilst they grow up their waist is growing but also their height.”

Losing weight when obese can prevent or cure diabetes, whatever the initial BMI, study suggests

Losing weight when obese can prevent or cure diabetes, whatever the initial BMI, study suggests.

ScienceDaily

May 6, 2012 

Lowering your BMI by five units can dramatically reduce your risk of diabetes, whatever your initial weight, says new research presented at the International Congress of Endocrinology/European Congress of Endocrinology in Florence, Italy. The findings show that even severely obese patients with diabetes can potentially rid themselves of the disease.

8 women with the same Body Mass Index rating (...

8 women with the same Body Mass Index rating (BMI – 30) but with different weight distribution and abdominal volume, so they have different Body Volume Index (BVI) ratings. Select Research, 09-09-08 (Photo credit: Wikipedia)

Addressing diabetes is a major priority for health providers worldwide given the vast global prevalence (approx. six to seven per cent of the world’s population; around 285 million people) and its severe complications including amputations and heart disease. Surgery for weight loss has an unexpectedly rapid and substantial therapeutic effect on diabetes rates. Understanding why weight loss has such a dramatic effect on diabetes is the focus of this study by Associate Professor Markku Peltonen from the National Institute for Health and Welfare, Finland and colleagues from the University of Gothenburg, Sweden.

The researchers enrolled the 2010 patients from the Swedish Obese Subjects study who had received bariatric surgery and 2037 obese controls receiving conventional (non-surgical) obesity treatment. They were assessed for BMI and diabetes at baseline (before surgery in the surgical group), and at two and 10 year follow-up.

The findings suggest that losing five BMI units, the equivalent of approx. 16kg for a 180cm tall 35 year old man weighing 130kg (BMI 40), can make a real difference to your health by reducing your likelihood of having type 2 diabetes. Furthermore, it suggests that this is true for all patients, as even those who were severely obese showed dramatic improvements.

Associate Professor Markku Peltonen, Director of Department at the National Institute for Health and Welfare, Finland, said:

“Our findings show that, whatever your starting weight, losing five BMI units can dramatically reduce your risk of having type 2 diabetes after two and ten years.

“Dropping five BMI units is no mean feat, as the human body is not very good at losing weight. But patients of any weight should take encouragement that by doing so they can really improve their chances of a healthy future.”

via Losing weight when obese can prevent or cure diabetes, whatever the initial BMI, study suggests.

How sleep affects your ‘fat genes’

How sleep affects your ‘fat genes’ – and your ‘fat jeans’ – The Globe and Mail.

Globe and Mail Blog

Lack of sleep not only makes you cranky and accident prone – it may also put your “fat genes” into high gear, a new study suggests.

“The less sleep you get, the more your genes contribute to how much you weigh. The more sleep you get, the less your genes determine how much you weigh,” lead author and neurologist Nathaniel Watson told USA Today.

Dr. Watson and colleagues at the University of Washington Medicine Sleep Center in Seattle looked at the height, weight and sleep habits of 604 pairs of identical twins and 484 sets of fraternal twins. After analyzing the data, they reached the following conclusions:

  • Individuals who slept longer at night had lower body mass index (BMI) than those sleeping less.
  • For twins who got more than nine hours of sleep a night, genetic factors accounted for about 32 per cent of weight variations.
  • For twins who averaged less than seven hours, 70 per cent of weight variations were due to genetic factors.

Dr. Watson noted that both BMI and the need for sleep are inherited traits. Even so, “we see differences in how much twins weigh based on their sleep duration,” he said.

That doesn’t mean people can sleep themselves thin, Dr. Watson told the Huffington Post. “But you can sleep yourself to a point where environmental factors, like diet and activity, are more important in determining your body weight than genetics.”

The research may seem at odds with a 2008 study showing a link between excess sleep – more than nine hours a night – and obesity. But researchers of that study, conducted by the U.S. National Center for Health Statistics, found that nearly half of people who slept nine hours or more each night were physically inactive in their leisure time, and many had serious health problems.

Dr. Watson and his co-authors acknowledged that more than 20 genes are involved in regulating energy use, fat storage, appetite and the body’s ability to process glucose.

Still, “there is an amount of sleep where people become less healthy,” Dr. Watson told ABC News. “Most people need between 7 and 9 hours a night.”

How Lack of Sleep Directly Affects Your Metabolism

How Lack of Sleep Directly Affects Your Metabolism : Natural Society.

 : Natural Society

Patrick Gallagher
NaturalSociety
April 23, 2012

sleepless3 220x137 How Sleep Directly Affects Your MetabolismHave you ever wondered why there are so many cases of obesity, high blood pressure, and heart disease among the people you work with and live around? In many cases, there are multiple reasons for this, including dietary issues, work stress, and a number of other factors, but there is a very high likelihood that those people may be suffering from such ailments because of one key reason: sleeplessness.

Indeed, the lack of sleep experienced by American citizens is one of the key debilitating factors squandering a great deal of the human resources that we need to function as a society. It is a consistent uphill battle under the veil of sleeplessness for each one of us whether we realize it or not; unfortunately, many people don’t realize they are lacking sleep. The greatest thanks for our mass sleeplessness can go to the concerted efforts of the industries offering sugary beverages, and the more recent energy drink frenzy that a high percentage of the populace consumes. The great, diverse variety of sugared drinks that the populace has the power to choose over natural, healthy alternatives is one of the greatest faults of the industry.

The most recent study by Dr. Kristen Knutson from the Univ. of Chicago describes the many ways sleeplessness can destroy your body’s ability to metabolize properly. Dr. Knutson gathered a sum of evidence from several observational studies of sleep showing a direct correlation to Body Mass Index (BMI) and fewer than 6 hours of sleep.

“Obesity develops when energy intake is greater than expenditure. Diet and physical activity play an important part in this, but an additional factor may be inadequate sleep [...] A review of the evidence shows how short or poor quality sleep is linked to increased risk of obesity by de-regulating appetite, leading to increased energy consumption.”

Not only does lack of sleep pose a threat to your heart, weight, and stress levels, but it also increases the risk of cancer, diabetes, and other conventional illnesses, in part by substantially diminishing the immune system’s primary organs. There are, of course, several hundred myths and theories on how much sleep an adult actually needs, and certain studies continue to perpetuate an alarmingly large number of them.

Sleeping

Sleeping (Photo credit: soylentgreen23)

Given the fact that at least one third of the population of America sleeps less than 7 hours a night, it is clear that our nation’s priorities may need a re-assessment. No amount of work or stress on a person can be reversed if they are not sleeping for a sufficient amount of time.

Explore More:

  1. Infographic | Why You Need More Sleep
  2. Insufficient Sleep for Teens May Lead to Weight Gain
  3. Is Your Sleep Schedule Preventing You from Reaching Optimum Health?

US obesity ‘higher than thought’

BBC News – US obesity ‘higher than thought’.

obese man How should obesity be calculated?

The obesity problem in the US may be much worse than previously thought, according to researchers.

They said using the Body Mass Index or BMI to determine obesity was underestimating the issue.

Their study, published in the journal PLoS One, said up to 39% of people who were not currently classified as obese actually were.

The authors said “we may be much further behind than we thought” in tackling obesity.

BMI is a simple calculation which combines a person’s height and weight to give a score which can be used to diagnose obesity. Somebody with a BMI of 30 or more is classed as obese.

The US Centers for Disease Control says at least one in three Americans are obese.

Many more?

Other ways of diagnosing obesity include looking at how much of the body is made up of fat. A fat percentage of 25% or more for men or 30% or more for women is the threshold for obesity.

One of the researchers Dr Eric Braverman said: “The Body Mass Index is an insensitive measure of obesity, prone to under-diagnosis, while direct fat measurements are superior because they show distribution of body fat.”

The team at the New York University School of Medicine and the Weill Cornell Medical College, New York, looked at records from 1,393 people who had both their BMI and body fat scores measured.

Their data showed that most of the time the two measures came to the same conclusion. However, they said 539 people in the study – or 39% – were not labelled obese according to BMI, but their fat percentage suggested they were.

They said the disparity was greatest in women and became worse when looking at older groups of women.

“Greater loss of muscle mass in women with age exacerbates the misclassification of BMI,” they said.

They propose changing the thresholds for obesity: “A more appropriate cut-point for obesity with BMI is 24 for females and 28 for males.”

A BMI of 24 is currently classed as a “normal” weight.

“By our cut-offs, 64.1% or about 99.8 million American women are obese,” they said.

It is not the first time BMI has been questioned. A study by the University of Leicester said BMIs needed to be adjusted according to ethnicity.

Last year in the BBC’s Scrubbing Up column, nutrition expert Dr Margaret Ashwell advocated using waist-to-height ratio to determine obesity.

She said: “It is a real worry that using BMI alone for screening could miss people who are at risk from central obesity and might also be alarming those whose risk is not as great as it appears from their BMI.”

Chocolate lovers rejoice: It can help keep you slim !

Chocolate ‘can help keep you slim’ – Health News – Health & Families – The Independent.

A chocolate bar and melted chocolate. Chocolat...

A chocolate bar and melted chocolate. Chocolate is made from the cocoa bean, which is a natural source of theobromine. (Photo credit: Wikipedia)

Far from piling on the pounds, a chocolate habit can help keep you slim, new research suggests.

Just in time for Easter, scientists have announced the discovery every chocolate lover has been waiting for.

A study has found that, despite boosting calorie intake, regular chocolate consumption is related to lower body mass index (BMI).

The effect is modest but greater than can be explained by chance, say the US researchers who took account of influencing factors such as overall fat consumption and exercise.

BMI relates height and weight and is the standard measurement used to assess levels of obesity.

The good news about chocolate emerged after scientists screened a group of 972 men and women with an average age of 57 for a study of statins – cholesterol-lowering drugs.

Among other diet and lifestyle questions, participants were asked: “How many times a week do you consume chocolate?”

Chocolate is known to contain plant chemicals called polyphenols that combat heart disease and may influence metabolism.

The researchers suspected they might, to some extent at least, off-set the unwelcome effects of high saturated fat levels in chocolate bars and sweets.

No account was taken of different types of chocolate, some of which contain more healthy elements than others.

The results showed that chocolate was not only “calorie neutral” but actually appeared to make people slimmer.

Participants who ate chocolate on more days of the week than average were statistically likely to have a lower BMI than those who did not.

This was despite the fact that people who ate more chocolate did not consume fewer calories overall, or take more exercise.

In fact they ate more – chocolate consumption was associated with greater overall saturated fat intake.

Volunteers had an average BMI of 28 – meaning they were overweight – and ate chocolate on average twice a week. No link was seen between the amount of chocolate eaten and either higher or lower BMI.

The findings appear in Archives of Internal Medicine, published by the Journal of the American Medical Association.

Study leader Dr Beatrice Golomb, from the University of California at San Diego, said: “Our findings appear to add to a body of information suggesting that the composition of calories, not just the number of them, matters for determining their ultimate impact on weight.

“In the case of chocolate, this is good news – both for those who have a regular chocolate habit, and those who may wish to start one.”

The scientists pointed out that chocolate products “are often rich in sugar and fat, contributing to assumptions that chocolate boosts BMI”.

They added: “This study does not obviate the possibility that some chocolate-containing products do so, that some chocolate consumption profiles do so, or that for some people, even frequent modest chocolate consumption does so.

“Moreover, since findings are cross-sectional, causality in the observed association cannot be assumed. However, the finding fits with the literature suggesting benefits of chocolate for other metabolic factors.”

Previous research on rodents has suggested that chemicals in chocolate might speed up metabolism.

One chemical derived from the chocolate ingredient cocoa, epicatechin, has been shown to boost numbers of mitochondria, the cell’s energy-generating “power houses”. Mitochondria burn up calories.

Epicatechin reduced weight in rats whose calorie intake and exercise levels were unchanged.

“Parallel processes in humans, if present, could underlie our findings,” Dr Golomb’s team concluded in their research article.

The results justified a randomised trial looking at the metabolic benefits of chocolate in humans, said the scientists.

Forget the scale: the 5 numbers that really impact your health

If you want to maximize your chances of following through on your New Year’s resolution to lose weight and get fit, then you need to start tracking your progress. Doing so will give you a clear picture of where you are in relation to your goals, which is much better than some fuzzy notion of feeling like you’re doing well. But pile on too many metrics and it’s easy to get lost in all the data. Here are the five most important health and fitness numbers to strive for in 2012.

5.2

What: Your total cholesterol – which includes both “good” HDL and “bad” LDL cholesterol – should be below 5.2 millimoles per litre of blood.

Why track it: “Every adult should be aware of their lipid levels,” says Dr. Andy Wielgosz, a cardiologist and spokesman for the Heart and Stroke Foundation of Canada. Knowing your cholesterol levels will help you understand just how at risk you are for several conditions, and just how much you need to reduce your cholesterol, which can be done with plenty of fresh fruit and vegetables, Dr. Wielgosz says.

Health risks: “High cholesterol contributes to the build up of atherosclerosis, or plaque, which is that mucky stuff that plugs up the arteries. And that can result in strokes, heart attacks and pain in the legs,” Dr. Wielgosz. It can also cause aneurysms.

150

What: Canada’s latest physical activity guidelines, introduced earlier this year, recommend that adults 18 to 64 get at least 150 minutes of moderate to vigorous intensity aerobic physical activity each week.

Why track it: Many of us don’t make time for exercise, so we need to be diligent. More than half of Canadian adults are now deemed to be physically inactive. At the same time, obesity levels and the rates of several diseases, including many types of cancer and Type II diabetes, are on the rise. Be very conscious of when you’re exercising if you want to meet your goal of getting fit, says Audrey Hicks, former president of the Canadian Society for Exercise Physiology, which created the guidelines. “Scheduling physical activity into your weekly routine is probably much more likely to find success than just doing it if you find the time,” she says.

Health risks: Regular physical activity reduces your risk of chronic diseases, including hypertension, high blood-glucose levels, high blood-lipid levels and can even improve a person’s mental health, Dr. Hicks says. Inactivity has been linked to several types of cancers, obesity and Type II diabetes, among other diseases and conditions.

140 over 90

What: The measure of blood pressure over which is considered high.

Why track it: High blood pressure, or hypertension, “still remains the No. 1 risk for premature death in Canada, in North America and in the world,” says Dr. Ross Feldman, president of Hypertension Canada. One in five adults have hypertension, according to Statistics Canada. As a measure of overall cardiovascular health, there is no better metric than blood pressure. Ideally, your systolic pressure, or top number, should be between 115 to 120, Dr. Feldman says, “but there’s no evidence that lowering your blood pressure below 140 over 90 is of any benefit unless you have diabetes.”

Health risks: “The most direct risk is with stroke,” Dr. Feldman says. Other risks include to coronary heart disease and kidney disease, he says.

60 to 90

What: The normal range of an adult’s resting heart rate, as measured in beats per minute.

Why track it: Your resting heart rate is a good indicator of your overall cardiovascular efficiency. Very fit athletes, for instance, can see their resting heart rate in the 40s, says Dr. Hicks. “It’s an indication of the strength of your heart muscle,” she says. If you want to know how fit you are, there are few easier ways to measure than by getting a watch, finding your pulse and calculating your resting heart rate.

Health risks: “If somebody routinely has a resting heart rate above 90 beats per minute they should probably get themselves checked by a doctor because it could be reflective of some sort of problem with the heart itself,” Dr. Hicks says.

25

What: The turning point from normal weight to overweight on the BMI scale.

Why track it: The Body Mass Index is a measure of body fat based on a person’s height and weight (to calculate your BMI, simply divide your weight by your height). People with a BMI of between 18.5 and 24.9 are considered normal weight. Those with a BMI of 25 or higher are considered overweight, while 30 or higher means you’re obese. Nearly one-quarter of Canadian adults are now obese, according to Statistics Canada. “There’s no question that as BMI per se increases, unless you’re growing taller, then that’s generally associated with increased health risk,” says Dr. Robert Ross, director of the Centre for Obesity Research and Education at Queen’s University.

Health risks: “It’s hard to think of any kind of morbidity [not associated with increased BMI],” Dr. Ross says.

English: Heart rate versus age.

Image via Wikipedia

via Forget the scale: the 5 numbers that really impact your health – The Globe and Mail.

Obesity in middle age increases risk of dementia

obesity

Being obese can dramatically increase the risk of developing dementia later in life. Photograph: Fiona Hanson/PA

People who are obese in middle age are at almost four times greater risk of developing dementias such as Alzheimer’s disease in later life than people of normal weight, according to a study released today.

The study, published in the journal Neurology, examined data on more than 8,500 people over the age of 65. Of the sample, 350 had been diagnosed with Alzheimer’s disease or vascular dementia and a further 114 had possible dementia.

Scientists used records of the participants’ height and weight in the decades before and found that those who had been overweight in middle age had a 1.8 times (80%) higher risk of being diagnosed with dementia in later life. But for obese people, classified as those having a body mass index (BMI) of 30 or above, the risk soared. People with midlife obesity had an almost four times (300%) higher risk of dementia.

“Currently, 1.6 billion adults are overweight or obese worldwide and over 50% of adults in the US and Europe fit into this category,” said Weili Xu of the Karolinska Institutet in Stockholm, who led the research. “Our results contribute to the growing evidence that controlling body weight or losing weight in middle age could reduce your risk of dementia.”

According to the Alzheimer’s Society, around 750,000 people in the UK suffer from dementia, more than half of those with Alzheimer’s. By 2021, a million people will be living with dementia.

Obese people are classified as those with BMI greater than 30, overweight people are those with a BMI between 25 and 30. Between 20 and 25 is classified as normal. Almost 30% of those in the study, 2,541 in total, had been either overweight or obese between 40 and 60 years of age.

“Although the effect of midlife overweight on dementia is not as substantial as that of obesity, its impact on public health and clinical practice is significant due to the high prevalence of overweight adults worldwide,” said Xu.

Susanne Sorensen, head of research at the Alzheimer’s Society, said: “This robust study adds to the large body of evidence suggesting that if you pile on the pounds in middle age, your chances of developing dementia are also increased.By eating healthily and exercising regularly, you can lessen your risk of developing dementia. Not smoking and getting your cholesterol and blood pressure checked regularly is also very important.”

Xu agreed that healthy living in middle age can help to reduce a person’s risk of developing dementia in later life and added that a person’s experience of education also played a role in the rate of decline of the brain. “Based on this data, every one year in higher education is associated with about 10% reduced risk of overweight and obesity, and 8% decreased risk of dementia.”

Exactly how excess weight can influence the degradation of the brain is not certain, but Xu said there could many possible mechanisms. “Higher body fat is associated with diabetes and vascular diseases, which are related to dementia risk,” she said.

In addition, fatty tissue is the largest hormone-producing organ in the body and it can produce inflammatory molecules which may affect cognitive functioning or the process of neurodegeneration.

Sorensen said that further research was needed to find the links between being overweight and dementia. “One in three people over 65 will die with dementia, yet research into the condition is desperately underfunded.”

The Alzheimer’s Society has launched the Drug Discovery programme, which it says could lead to new treatments for dementia within a decade. Scientists will screen compounds that have already been licensed for other conditions, to see if they have any effect on the causes of Alzheimer’s disease.

Jeremy Hughes, chief executive of Alzheimer’s Society, said not enough clinical trials for dementia were taking place in the UK. “We need £4,000 every day for the next 10 years for the first phase of this groundbreaking initiative, and we are asking all those concerned with dementia to help us raise this. Together, we can transform hundreds of thousands of lives.”

Obesity in middle age increases risk of dementia | Science | The Guardian.