Above-normal weight alone does not increase the short-term risk of death: study
An evaluation of national data by UC Davis researchers has found that extra weight is not necessarily linked with a higher risk of death.
When compared to those with normal weight, people who were overweight or obese had no increased risk of death during a follow-up period of six years. People who were severely obese did have a higher risk, but only if they also had diabetes or hypertension.
The findings, which appear in the July-August issue of The Journal of American Board of Family Medicine, call into question previous studies -- using data collected when obesity was less common -- linking higher short-term mortality with any amount of extra weight.
"There is currently a widespread belief that any degree of overweight or obesity increases the risk of death, however our findings suggest this may not be the case," said Anthony Jerant, professor of family and community medicine and lead author of the study. "In the six-year timeframe of our evaluation, we found that only severe obesity was associated with an increased risk of death, due to co-occurring diabetes and hypertension."
Based on the study, Jerant recommends that doctors' conversations with patients who are overweight or obese, but not severely obese, focus on the known negative effects of these conditions on mental and physical functioning, rather than on an increased short-term risk of death.
By contrast, Jerant added that it is important for doctors to talk with severely obese patients who also have diabetes or hypertension about their increased short-term mortality risk and treatment, including weight loss.
"Our results do not mean that being overweight or obese is not a threat to individual or public health," said Jerant. "These conditions can have a significant impact on quality of life, and for this reason alone weight loss may be advisable."
In conducting the study, Jerant used nationwide data from 2000 to 2005 of nearly 51,000 adults aged 18 to 90 years who participated in the Medical Expenditure Panel Surveys on health-care utilization and costs. The surveys include information on health conditions such as diabetes and hypertension.
Body mass index (BMI), or weight adjusted for height, was calculated for each respondent. The study categorized people as underweight (BMI < 20), normal weight (BMI 20 to < 25), overweight (BMI 25 to < 30), obese (BMI 30 to 35) or severely obese (BMI > 35).
Mortality was assessed using the National Death Index. Of the 50,994 people included in the UC Davis analysis, just over 3 percent (1,683) died during the six years of follow-up.
The investigators found that severely obese people were 1.26 times more likely to die during follow-up than people in the normal weight group. However, if people with diabetes or hypertension were eliminated from the data, those who were overweight, obese or even severely obese had similar or even lower death rates than people of normal weight. Consistent with a number of prior studies, underweight people were nearly twice as likely to die than people with normal weight, regardless of whether diabetes or hypertension was present.
The prevalence of overweight and obesity has increased dramatically in recent decades. An estimated one-third of all U.S. adults over age 20 are obese and another one-third are overweight. In addition to diabetes and hypertension, health problems associated with these conditions include heart disease, osteoarthritis and sleep apnea.
The relationship between weight and mortality is a controversial topic in public health. Although studies based on data collected 30 years ago showed that mortality risk rose as weight increased, analyses of more recently collected data, including the current one, call this assumption into question.
"Our findings indicate that the risk of having an above-normal BMI may be lower than in the past," said Jerant. "While this study cannot explain the reasons, it is possible that as overweight and obesity have become more common, physicians have become more aware of associated health issues like high blood pressure, cholesterol and blood sugar, and are more aggressive about early detection and treatment of these conditions."
Jerant said that the six-year period of his investigation limits the ability to make assumptions about the link between unhealthy weight and the risk of death over a longer timeframe.
"We hope our findings will trigger studies that re-examine the relationship of being overweight or obese with long-term mortality," said Jerant.
More information: A copy of "Body mass index, diabetes, hypertension and short-term mortality: A population-based observational study 2000-2006" is available at www.jabfm.org/content/current .
Provided by Queen's University Belfast
- Weight gain may be healthy when it comes to type 1 diabetes Jun 07, 2008 | not rated yet | 0
- Study examines association between weight amount and cause of death Nov 08, 2007 | not rated yet | 0
- Obese and overweight women, children underestimate true weight Mar 23, 2011 | not rated yet | 0
- Physician's weight may influence obesity diagnosis and care Jan 26, 2012 | not rated yet | 0
- Being overweight just as risky to health as being a smoker Feb 25, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
A new way of interpreting information from a low-tech, age-old method used in pregnancy care is expected to more accurately identify potential health issues for mothers and babies.
Health 2 minutes ago | not rated yet | 0
Artemio Martinez balanced his corpulent frame on a stool in a Mexico City street taco stand, downing a sweet soda and eating a final pork-filled corn tortilla.
Health 2 hours ago | not rated yet | 0
People eating at fast food restaurants largely underestimate the calorie content of meals, especially large ones, according to a paper published today in BMJ.
Health 13 hours ago | not rated yet | 0
Don't doubt it when a woman harried by hot flashes says she's having a hard time remembering things. A new study published online in Menopause, the journal of The North American Menopause Society (NAMS), helps confirm with o ...
Health 15 hours ago | not rated yet | 0
(Medical Xpress)—The way Alzheimer's disease is portrayed by advocacy groups and the media is having undue influence on the euthanasia debate, according to a Deakin University nursing ethics professor.
32 minutes ago | not rated yet | 0
(Medical Xpress)—Patients with diabetes who are depressed are much more likely to develop episodes of dangerously low blood sugars, or hypoglycemia, than are those who are not depressed, a new study has ...
28 minutes ago | not rated yet | 0 |
(Medical Xpress)—Curtin University researchers have found evidence that targeting specific cells in the body can reverse the effects of cancer on the immune system.
2 minutes ago | not rated yet | 0
Can human genes be patented? That was the question posed by Alan J. Snyder, vice president and associate provost for research and graduate studies at Lehigh, and Lee Kaplan, scientific director of cellular and molecular genetics ...
45 minutes ago | 4 / 5 (1) | 0
A new program for treating the emotional health of mothers of children with ADHD has shown significant benefits for the children themselves, finds a new study by University of Maryland researchers. The program combines treatment ...
2 minutes ago | not rated yet | 0
Cardiac study used as source for new guidelines on treating people undergoing coronary artery bypass surgery
Cardiac research from the University of Alberta had serious impact as a source for the American College of Cardiology and the American Heart Association's new guidelines on how to treat patients undergoing coronary artery ...
22 minutes ago | not rated yet | 0