2012 September 26 Wednesday
Some Obese People Perfectly Healthy?

Are 30% to 40% of the obese at no higher risk of mortality than normal weight people?

A person can be obese and metabolically healthy at the same time, which means that this person will have the same mortality risk for heart disease or cancer that people of normal weight. This is the conclusion of a study published in the prestigious journal European Heart Journal [1].

"Obesity is associated with a large number of chronic diseases as heart diseases or cancer. However, there is a group of obese people that do not suffer the metabolic complications associated with obesity", the author of the study, Prof. Francisco B.Ortega, explains.

If the existence of a healthy minority of obese people is real then why? Exercise or genetic adaptation to higher weight?

Prof. Ortega et al. observed in their study that between 30-40% of obese patients were metabolically healthy. "We made two findings: firstly, metabolically-healthy obese people exhibited better cardiorespiratory fitness –or aerobic fitness-. Secondly, this subgroup has a lower mortality risk rate for heart disease or cancer than other obese people, and has the same mortality risk than people of normal weight." "This study concludes that, regardless of body weight and fat, people with better aerobic fitness have a lower risk for heart or cancer disease and death", Dr. Ortega states.

The obese probably ought to be metabolically profiled to identify those who most need to lose weight.

By Randall Parker    2012 September 26 10:14 PM   Entry Permalink | Comments (4)
2010 December 02 Thursday
Body Mass Index Above 25 Raises Mortality Risk

Pooling data from 19 long term studies researchers find shorter life expectancies for body mass indexes above 24.9.

A study looking at deaths from any cause found that a body mass index (BMI) between 20.0 and 24.9 is associated with the lowest risk of death in healthy non-smoking adults. Investigators also provided precise estimates of the increased risk of death among people who are overweight and obese. Previous studies that examined the risks from being overweight were inconclusive, with some reporting only modestly increased risks of death and others showing a reduced risk. Also, the precise risks for different levels of obesity were uncertain. The research team included investigators from the National Cancer Institute (NCI), part of the National Institutes of Health, and collaborators from a dozen other major research institutions worldwide. The results appear in the Dec. 2, 2010, issue of the New England Journal of Medicine.

From 25 to 29.9 BMI all cause mortality went up 13%. Your risk will be higher at 29.9 than at 25.

They found that healthy women who had never smoked and who were overweight were 13 percent more likely to die during the study follow-up period than those with a BMI between 22.5 and 24.9. Women categorized as obese or severely obese had a dramatically higher risk of death. As compared with a BMI of 22.5 to 24.9, the researchers report a 44 percent increase in risk of death for participants with a BMI of 30.0 to 34.9; an 88 percent increase in risk for those with a BMI of 35.0 to 39.9; and a 2.5 times (250 percent) higher risk of death for participants whose BMI was 40.0 to 49.9. Results were broadly similar for men. Overall for men and women combined, for every five unit increase in BMI, the researchers observed a 31 percent increase in risk of death.

You can calculate your BMI here. Then dial back your weight to see how low it has to go to get below a BMI of 25. That's the goal to shot for.

Update If you are a low fat, high muscle guy then you could have a high BMI that does not indicate higher disease risk. But usually BMI is a decent proxy for body fat because so few people are buff, especially among those in middle age and beyond.

By Randall Parker    2010 December 02 10:30 PM   Entry Permalink | Comments (12)
2010 September 30 Thursday
Trans Fats Boost Baby Obesity?

One can easily find lots of competing theories for the obesity boom including omega 6 fatty acids and fructose. Here's another possibility: Does mom's consumption of junk foods high in trans fats boost baby obesity?

Athens, Ga. – A new University of Georgia study suggests that mothers who consume a diet high in trans fats double the likelihood that their infants will have high levels of body fat.

What fructose, trans fats, and omega 6 fatty acids all have in common: their portion of our diets went up as obesity rose. From that perspective they make obvious suspects. So it makes sense to pay attention to research linking any of them to the rise in obesity, insulin resistant diabetes, and other elements of metabolic syndrome.

Researchers, whose results appear in the early online edition of the European Journal of Clinical Nutrition, found that infants whose mothers consumed more than 4.5 grams of trans fats per day while breastfeeding were twice as likely to have high percentages of body fat, or adiposity, than infants whose mothers consumed less than 4.5 grams per day of trans fats.

The researchers investigated different fatty acids, but determined trans fats to be the most important contributor to excess body fat. "Trans fats stuck out as a predictor to increased adiposity in both mothers and their babies," said study co-author Alex Anderson, assistant professor in the UGA College of Family and Consumer Sciences.

Trans fats are certainly harmful and to be avoided. You might think, however, that since trans fat consumption is an approximate proxy for junk food consumption that other elements of junk food are as much to blame as trans fats. For example, a medium order of french fries can over 3 times the 4.5 grams threshold reported in this study. But in the last 5 years fast food restaurants such as McDonald's dropping the use of trans fats in french fry oil. Many commercial doughnuts have 5 grams of trans fat. But if you must eat doughnuts be aware that Dunkin Donuts stopped using trans fats in October 2007. I quite like the honesty of Dunkin Donuts about this move: They only made the doughnut less unhealthy, no pretending.

“The goal was not to make a healthy doughnut, it was really to create a doughnut that was better,” said Joe Scafido, Dunkin’s chief creative and innovation officer. “Certainly, we did not create a healthy doughnut.”

KFC eliminated trans fat from chicken frying in 2007. Other restaurant chains have cut trans fats as well including Wendy's. But your lowest odds of eating trans fat in restaurants comes from eating in jurisdictions where it is banned: California, NYC, some New York State counties and some other jurisdictions have banned restaurant trans fats. But it isn't clear to me whether any of these bans extend to grocery store food food. Anyone know?

My advice: avoid trans fats entirely. Cut your omega 6 fatty acid consumption. Get more omega 3s. Avoid high fructose corn syrup too. Roll back the big changes in diet that accompanied the rise in obesity.

By Randall Parker    2010 September 30 10:04 PM   Entry Permalink | Comments (5)
2010 June 30 Wednesday
Multivitamin Causes Weight Loss In Obese

Neurobiology researcher and nutrition blogger Stephan Guyenet points to a study which found that a multivitamin supplement caused weight loss in obese people.

A new study in the journal Obesity, by Y. Li and colleagues, showed that compared to a placebo, a low-dose multivitamin caused obese volunteers to lose 7 lb (3.2 kg) of fat mass in 6 months, mostly from the abdominal region (4). The supplement also reduced LDL by 27%, increased HDL by a whopping 40% and increased resting energy expenditure.

Click thru to see a list of what was in the supplement and Stephan Guyenet's discussion of the study. He is correct that this study should be repeated with Western populations. Be sure to read the comments as he attracts some commenters who are familiar with research literature and his responses to commenters are enlightening. Note one commenter points to research on high doses niacin and niacinamide as potential contributors to obesity.

Has any reader come across a study comparing the diet of the average obese person to that of the average non-obese person of the same age? Do obese people eat food that is, on average, lower in micronutrients than non-obese people?

On a similar note: On average do obese people have lower levels of any micronutrients as compared to non-obese people?

By Randall Parker    2010 June 30 10:51 PM   Entry Permalink | Comments (1)
2010 May 04 Tuesday
Obesity Lowers Male Testosterone?

A connection exists between obesity and testosterone.

BUFFALO, N.Y. -- Obesity, a condition linked to heart disease and diabetes, now appears to be associated with another health problem, but one that affects men only -- low testosterone levels.

Results of a study published online ahead of print in the journal Diabetes Care, conducted by University at Buffalo endocrinologists, showed that 40 percent of obese participants involved in the Hypogonadism in Males (HIM) study had lower-than-normal testosterone readings.

The percentage rose to 50 percent among obese men with diabetes. Results also revealed that as body mass index (BMI) -- a relationship of weight–to-height -- increased, testosterone levels fell.

Longitudinal studies to show how testosterone varies with time as people diet and gain weight would help to sort out the direction of causation. Does obesity lower testosterone or does the causality flow from a testosterone drop causing a weight gain?

Diabetes also might lower testosterone.

"The effect of diabetes on lowering testosterone levels was similar to that of a weight gain of approximately 20 pounds," says Sandeep Dhindsa, MD, an endocrinology specialist in the UB Department of Medicine and first author on the study.

Obese men could try testosterone to see if it helped take the weight off.

By Randall Parker    2010 May 04 12:43 AM   Entry Permalink | Comments (13)
2010 March 02 Tuesday
Inflammation In Obese 3 Year Olds

You might be wondering why 3 year olds are fed to the point of obesity. I know I am.

CHAPEL HILL – A study by University of North Carolina at Chapel Hill researchers found that obese children as young as 3 years old have elevated levels of C-reactive protein, a marker of inflammation that in adults is considered an early warning sign for possible future heart disease.

In addition, the study found elevated levels of two other inflammatory markers – the ratio of ferritin/transferrin saturation (F/T) and the absolute neutrophil count (ANC) – in obese children. Elevated F/T levels started at age 6 and elevated ANC levels were found starting at age 9.

High fructose corn syrup in baby foods is probably contributing to this outcome. But parents with obese babies really ought to notice and respond appropriately.

By Randall Parker    2010 March 02 10:01 PM   Entry Permalink | Comments (18)
2010 January 28 Thursday
Moderately Overweight Elderly Live Longer?

Once you hit 70 is being overweight actually adaptive?

Adults aged over 70 years who are classified as overweight are less likely to die over a ten year period than adults who are in the 'normal' weight range, according to a new study published today in the Journal of The American Geriatrics Society.

It is hard to tease out the direction of cause and effect in a study such as this one. For example, a person who was overweight in their 50s and into their 60s could develop a disease that causes weight loss down to a "normal" weight by the time they hit 70. Then they die in their 70s from a disease that caused them to lose weight in their 60s. Not saying this result is explained by that possibility. But one must consider the possibility of disease causing weight loss years before diagnosis.

Researchers looked at data taken over a decade among more than 9,200 Australian men and women aged between 70 and 75 at the beginning of the study, who were assessed for their health and lifestyle as part of a study into healthy aging. The paper sheds light on the situation in Australia, which is ranked the third most obese country, behind the United States and the United Kingdom.

Obesity and overweight are most commonly defined according to body mass index (BMI), which is calculated by dividing bodyweight (in kg) by the square of height (in metres). The World Health Organisation (WHO) defines four principal categories: underweight, normal weight, overweight, and obese. The thresholds for these categories were primarily based on evidence from studies of morbidity and mortality risk in younger and middle-aged adults, but it remains unclear whether the overweight and obese cut-points are overly restrictive measures for predicting mortality in older people.

The study began in 1996 and recruited 4,677 men and 4,563 women. The participants were followed for ten years or until their death, whichever was sooner, and factors such as lifestyle, demographics, and health were measured. The research uncovered that mortality risk was lowest for participants with a BMI classified as overweight, with the risk of death reduced by 13% compared with normal weight participants. The benefits were only seen in the overweight category not in those people who are obese.

It is also possible that a moderately overweight person who develops a disease that causes weight loss in their 70s might live longer than a skinnier person because overweight person has stored fat to live off of while their appetite is poor due to disease. I've watched someone close to me die from cancer where the death came sooner due to loss of appetite.

By Randall Parker    2010 January 28 11:46 PM   Entry Permalink | Comments (19)
2010 January 19 Tuesday
Gastric Bypass Benefit For Morbidly Obese

University of Cincinnati researchers found that gastric bypass surgery increases average life expectancy of the morbidly obese by 3 years.

Researchers led by Daniel Schauer, an assistant professor of medicine at UC, found the surgery added three years to the life expectancy of the average morbidly obese gastric bypass patient - a 42-year-old woman with a body mass index (BMI) of 45.

The benefits were greatest for younger patients.

The efficacy of surgery in reducing mortality was less important for older men, the analysis also showed. A 75-year-man with a BMI of 35 could expect only a very slight gain in life span -- perhaps one or two months.

"Younger patients have lower surgical risk and more time over which to realize the benefits of surgery. For older patients, the gain is smaller, and for some, gastric bypass surgery will decrease life expectancy," Schauer and colleagues wrote.

Mind you, surgical teams that do a lot of these procedures probably do so at lower risk. Since some people die due to complications of the surgery one needs to weigh the risks against the potential benefits.

Type 2 diabetes combined with obesity might also justify gastric bypass.

Jan 18, 2010 – Recent research shows surgical weight loss procedures like gastric banding and gastric bypass can help more type 2 diabetics manage, and potentially cure, their disease. In a study reviewed by the Diabetes Surgery Summit Consensus Conference, weight loss surgery was shown to help type 2 diabetics with a body mass index, also called BMI, of 30 or more control their disease. Surgery was previously recommended as an option to treat only those with a BMI of 35 or higher. The summit revised its recommendations for surgical treatment to include suitable candidates with a BMI between 30 and 35.

Gastric bypass cures type 2 diabetes in many overweight patients.

An Australian study published in the Journal of the American Medical Association in 2008 found that 73 percent of type 2 diabetics with BMIs between 30 and 40 were cured of the disease after receiving an adjustable gastric band. Just 13 percent of patients in the study achieved the same result with conventional therapies.

We really need safer ways to control appetite and weight.

By Randall Parker    2010 January 19 12:09 AM   Entry Permalink | Comments (2)
2009 November 22 Sunday
Some Obese See Themselves As Healthy

Some obese people even think they could gain weight.

ORLANDO, FLA., Nov. 17, 2009 — Some obese people misperceive that their body size is normal and think they don’t need to lose weight, according to research presented at the American Heart Association’s Scientific Sessions 2009.

In the Dallas Heart Study of 5,893 people, researchers found that 8 percent of the 2,056 who were obese said they were satisfied with their body size or felt they could gain weight.

“Almost one in 10 obese individuals are satisfied with their body size and didn’t perceive that they need to lose weight,” said Tiffany Powell, M.D., lead author of the study and a cardiology fellow at the University of Texas Southwestern Medical Center in Dallas. “That is a sizeable percentage who don’t understand they are overweight and believe they are healthy.”

Obesity contributes to a lot of health problems including breast cancer, prostate cancer and pancreatic cancer. So body weight delusions kill.

Update: Since obesity and blood risk factors are increasing delusions about weight are becoming more costly.

In a new study, researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 1988–2006, representing 8,264 adult men and women, 20 to 85 years old. All had complete risk factor profiles of their blood pressure, fasting glucose, low density lipoprotein (LDL or “bad” cholesterol) and smoking status.

Researchers found that during this time period, the average body mass index (BMI) increased from 26.5 to 28.8 kg/m2, a significant change. BMI – a measure of body fatness – is calculated by dividing a person’s weight in kilograms by height in meters squared. In the same period, the number of people with optimal blood pressure decreased from 48 percent in NHANES III, 1988–94, to 43 percent in NHANES in 2005–06, and the number of people with optimal fasting glucose decreased from 67 percent to 58 percent. Both blood pressure and blood glucose are closely linked to obesity and these adverse trends track with the change in body weight.

By Randall Parker    2009 November 22 08:12 PM   Entry Permalink | Comments (5)
2009 October 19 Monday
Moderately Overweight Live Just As Long?

Obesity is still seen as deadly but a body mass index between 25 and 30 might not reduce life expectancy.

Contrary to what was previously assumed, overweight is not increasing the overall death rate in the German population. Matthias Lenz of the Faculty of Mathematics, Computer Science, and Natural Sciences of the University of Hamburg and his co-authors present these and other results in the current issue of Deutsches Ärtzeblatt International (Dtsch Artzebl Int 2009; 106[40]: 641𔃆).

Most Germans are overweight, with a body mass index (BMI) between 25 and 29.9 kg/m2. About 20% are obese (BMI of 30 or over), with age- and gender-related differences. The authors systematically evaluated 42 studies of the relationships between weight, life expectancy, and disease.

The Süddeutsche Zeitung published an advance notice of the report (http://www.sueddeutsche.de/gesundheit/140/489526/text/), which shows that overweight does not increase death rates, although obesity does increase them by 20%. As people grow older, obesity makes less and less difference.

Keep in mind if you are gaining weight that even if your BMI is still under 30 you might be on path to a BMI up in the danger zone.

Being overweight does boost heart disease risk. But people who break their hips become less mobile and a lot less healthy. Being overweight trades off between different health risks.

For coronary heart disease, overweight increases risk by about 20% and obesity increases it by about 50%. On the other hand, a larger BMI is associated with a lower risk of bone and hip fracture.

In relation to cancer, the overall death rate among extremely obese men (BMI above 40) is no higher than among those of normal weight. Men who are overweight even have a 7% lower death rate. No significant association was found in women.

What I'm expecting: Genetic testing might show us what our relative risks are for a large variety of diseases and this knowledge could push us toward different ideal weights depending on which diseases we have the greater risks for. Also, some people are probably genetically better adapted to carrying more weight.

Note that you have other options for slowing bone decay aside from carrying more weight around. Exercise, better food, and a combination of vitamin D and vitamin K might cut bone fracture risks with age.

Weight studies are problematic because weight can vary due to muscle mass as well (albeit less often). Also, people can lose weight during the early stages of an illness before they even know they are sick. How well did the researchers adjust for these factors?

By Randall Parker    2009 October 19 10:39 PM   Entry Permalink | Comments (7)
2009 March 18 Wednesday
Biomarkers Show Faster Aging From Obesity, Stress

Telomere caps on chromosomes shorten with age. Obesity and stress are correlated with faster shrinking of telomere caps.

Women who maintain a healthy weight and who have lower perceived stress may be less likely to have chromosome changes associated with aging than obese and stressed women, according to a pilot study that was part of the Sister Study. The long-term Sister Study is looking at the environmental and genetic characteristics of women whose sister had breast cancer to identify factors associated with developing breast cancer. This early pilot used baseline questionnaires and samples provided by participants when they joined the Sister Study.

Two recent papers published in Cancer Epidemiology Biomarkers and Prevention looked at the length of telomeres, or the repeating DNA sequences that cap the ends of a person's chromosomes. Telomere length is one of the many measures being looked at in the Sister Study. Telomeres protect the ends of chromosomes and buffer them against the loss of important genes during cell replication. Over the course of an individual's lifetime, telomeres shorten, gradually becoming so short that they can trigger cell death. The papers show that factors such as obesity and perceived stress may shorten telomeres and accelerate the aging process.

Avoid obesity and stress. Easier said than done of course.

If you get overweight by 40 it is worse than getting overweight later. Probably it is a cumulative effect. The earlier you start the more total cellular damage builds up.

One of the studies published this week found that women who were obese for a long time had reduced telomere length. The researchers looked at the relationship between various measures of current and past body size and telomere length in 647 women enrolled in the Sister Study. They found that women who had an overweight or obese body mass index (BMI) before or during their 30s, and maintained that status since those years, had shorter telomeres than those who became overweight or obese after their 30s. "This suggests that duration of obesity may be more important than weight change per se, although other measures of overweight and obesity were also important," said Sangmi Kim, Ph.D., epidemiologist and lead author on the paper. "Our results support the hypothesis that obesity accelerates the aging process," said Kim.

If you feel stressed and your body has more stress hormones in it then that maximizes the effect of stress on telomere aging.

The other paper published in February looked at the association between telomere length and the perceived stress levels of 647 women enrolled in the Sister Study, and found that similar to the obesity finding, stress can also impact telomere length. The researchers extracted DNA from blood drawn during initial enrollment to estimate telomere length, and measured levels of stress hormones in urine samples the women provided. Additionally, the researchers used a standardized scale to characterize levels of perceived stress based on answers to questions about how stressful participants perceived their life situations. In general, the researchers report that women in the Sister Study typically reported low levels of perceived stress.

"Even so, women who reported above-average stress had somewhat shorter telomeres, but the difference in telomere length was most striking when we looked at the relationship between perceived stress and telomere length among women with the highest levels of stress hormones," said Christine Parks, Ph.D., an NIEHS epidemiologist and lead author on the paper. "Among women with both higher perceived stress and elevated levels of the stress hormone epinephrine, the difference in telomere length was equivalent to or greater than the effects of being obese, smoking or 10 years of aging."

Think about your job decisions, relationship decisions, investment decisions, and spending decisions from the standpoint of which potential decisions carry the risk of creating stress. Avoid putting yourself in situations where you stand a higher chance of feeling stressed. You'll age more slowly and live longer as a result.

Obesity cuts about 3 years off of life expectancy and extreme obesity cuts about 10 years off of life expectancy.

•Above a healthy weight, every 5-point increase in BMI increases the risk of early death by about 30%.

•People who are overweight but not obese, with a BMI between 25 and 29.9, could be shortening their life span by a year.

•People with the lowest risk of dying early are in the high end of the healthy weight range with a BMI of about 22.5 to 25.

Since most people by middle age are overweight a substantial number of people are losing out on some years of life. Here are more details on the study. Go calculate your body mass index (BMI).

By Randall Parker    2009 March 18 12:11 AM   Entry Permalink | Comments (3)
2008 June 19 Thursday
Weight Loss Surgery Cuts Cancer Risk

For those who are morbidly obese bariatric surgery causes a large cut in cancer risk.

Montreal, 19 June 2008 – Successful bariatric surgery allows morbidly obese patients to lose up to 70 percent of their excess weight and to maintain weight loss. The latest study by Dr. Nicolas Christou of the McGill University Health Centre (MUHC) and McGill University shows that this surgery also decreases the risk of developing cancer by up to 80 percent. Dr. Christou presented his preliminary results yesterday at the 25th Annual Meeting of the American Society for Metabolic & Bariatric Surgery.

The researchers compared 1,035 morbidly obese patients who underwent bariatric surgery at the MUHC between 1986 and 2002 with 5,746 patients with the same weight profile who did not undergo the operation. The number of cancer diagnoses in first group was 85 percent lower for breast cancer and 70 percent lower for colon and pancreatic cancers, and was also distinctly lower for several other types of cancer.

"The relationship between obesity and many forms of cancer is well established," said Dr. Christou. "This is one of the first studies to suggest that bariatric surgery might prevent the risk of cancer for a significant percentage of morbidly obese people."

By Randall Parker    2008 June 19 10:36 PM   Entry Permalink | Comments (1)
2007 August 27 Monday
Weight Gain With Age Slows As Muscle Converts To Fat

Down with aging. First people gain weight and then their muscles start dissolving into fat.

Researchers have discovered that middle age spread seems to have an effect on waistlines but not weight as people get older.

Researchers, funded by the Medical Research Council, have found that people in early middle age seem to put on more weight more quickly than people slightly older. But the waistlines of the older group seem to grow more quickly.

The stage when the waistlines start expanding more rapidly is when the muscles wither.

One of the researchers Geoff Der, from the MRC’s Social and Public Health Sciences Unit in Glasgow explained:

“As people get older it seems that their bodies change… they lose muscle and get fatter – this explains why middle-age spread might not be reflected on the bathroom scales.”

He goes on: “This challenges the traditional method of measuring how fat a person is: the body mass index. The BMI is a good measure of lean body tissue, but an expanding waistline may be a more reliable measure of the amount of fatty tissue a person has gained. Although the people in the older middle age group in this study appeared to put on less weight than the younger people, their waist circumferences continued to grow over time. What appears to have been happening is that the increase in fat was being obscured by a loss of muscle mass.’’

So first you gain weight. Then your weight gain slows but some of your muscle mass gradually converts to fat. How disgusting. Really, we need rejuvenation therapies. Aging takes away your muscles and makes you fat. This is something we can do without. We should support bigger efforts to figure out how to avoid the decay of aging.

When you head into middle age the odds of keeping the weight off are definitely against you.

The researchers carried out a nine-year study of 1044 people aged either 39 or 59 in 1991. The height, waist circumference and weight of each participant was measured in 1991, 1995 and 2000, and used to measure changes in body mass index over time.

Only one in five (20%) of the people maintained a stable weight as the study progressed. Steady weight gain was measured in the younger group, more than 42% of study participants put on 10kg, 17% gained 5kg.

On average, both men and women in the younger group gained between 0.5kg and 1kg a year. This weight gain was fastest in their younger years. Those in the older age group gained least weight in the second half of the study, however, although their overall weight may not have changed their waist circumference did.

Aging is bad. The physical changes that come from the accumulation of damage to your body are a big and increasing negative. I'm talking downsides. I'm talking losses. Something to be avoided.

We need to seriously try to develop treatments that will reverse the aging process. The defeat of aging is an achievable goal and it is a goal that will be achieved in this century. But whether it comes soon enough for most of us depends on how hard we push to achieve it.

By Randall Parker    2007 August 27 11:54 PM   Entry Permalink | Comments (15)
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