obesity

Anyone not living under a rock is aware that the prevalence of obesity in this country (and indeed around the world) has been increasing for decades. In this country alone, the spread of obesity (BMI>30) and severe obesity (BMI>40) has been appalling. For example, in 2011 between 30 and 35 percent of adults in 12 states had a BMI of 30 or more. By 2016, 25 states were in that category, and 5 of those had a prevalence of 35 percent or more.

So how are we doing now? A recent report provides a mixed message. Dr. Craig M. Hales and colleagues from the CDC analyzed trends in obesity prevalence of both adults (18 +) and youth (7-17 years)...

Parasitic worms aren't all bad.

Parts of the world in which people are still regularly infected by them tend to have lower levels of autoimmune disease. This and other observations have led to the hygiene hypothesis, which posits that the ultra-clean, super-hygienic setting of the developed world may be responsible for the rise of chronic conditions such as allergies and asthma.

In theory, some health conditions that involve dysregulation of the immune system, especially out-of-control inflammation, might be treated by making the patient less hygienic. This, in turn, has led to helminth therapy, the purposeful infection of a patient with parasitic worms. To survive, some parasites "turn down" the host's immune response, and...

Twenty years ago an expert panel at the NIH created a furor among obesity researchers by suggesting that the BMI cutoff point for a person to be considered overweight be lowered from 27 to 25. That guidance was accepted, and Americans' girths continued to rise. Now, an editorial in JAMA has suggested that we should lower that cut point even more — but for only one group — postmenopausal women.

We, and plenty of others, have pointed out the weakness of using BMI to indicate fatness, whether overweight, obese or extremely obese. In a...

In addition to the numerous metabolic problems (e.g. diabetes) associated with obesity, we can add problems with lung function. For example sleep apnea, a condition in which a person repeatedly awakens from sleep because of breathing problems is significantly associated with obesity. Other than this type of problem, which seems to be associated with mechanical restrictions, researchers question whether obesity, particularly abdominal obesity, is related to decreased lung functioning and whether such decreases are reversible if a person becomes less obese. Further, if excess fat around the middle is the issue, does it matter if that fat is subcutaneous (just under the skin) or visceral (around the abdominal organs).

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Noting that about 30 percent of obese individuals are metabolically healthy (1), Dr. Ann-Sophie Wedell-Neergaard from the University of Copenhagen in Denmark and colleagues, asked whether physical fitness or lack thereof was significantly associated with those characteristics. In particular, they examined possible correlations between fitness and abdominal obesity, which is the type most closely associated with negative metabolic characteristics, as well as with the presence of low-grade inflammation. Their hypothesis was that there was such an association — independent of Body Mass Index (BMI), which is an indicator of the degree of overall adiposity. Their report was published in PLOS ONE...

Severe obesity (BMI = or > 40, or 35 if there are coincident health conditions) carries with it a variety of increased health risks, such as for type 2 diabetes, high blood pressure, and heart problems. Bariatric surgery can successfully deal with the excess weight, and both prevent the occurrence of diabetes and, in some cases, cause its remission. However, there are several procedures that can be used: Roux-en-Y gastric bypass; sleeve gastrectomy; adjustable gastric banding. How to choose among them can be gleaned from a group of articles in the Journal of the American Medical Association (JAMA). Two of...

Weight stigma is real. Overweight and obese people are the targets of bias at work, school, at the doctor's office, within personal relationships and in the media.

A recent study published in Nature Genetics, describes a genetic link to obesity in humans discovered by studying obese children in Pakistan. One of the reasons that the genetics were uncovered in this region is because of the frequency of consanguinous (within the family) relationships. The genes that were identified are recessive mutations and exhibit a trait when two copies of the mutation are present - something that is much more likely to occur when families interbreed. 

Saeed et al. used genome sequencing to find mutations in one specific gene related to obesity, adenylate cyclase 3 (ADCY3). What...

Back in 2012, we noted the good news that the prevalence of obesity and severe obesity in children served by federal food assistance programs had diminished. The trend seems to be continuing according to more recent research. Between 2000 and 2014, the prevalence of severe obesity in children aged 2 to 4 years who were enrolled in the WIC (1) nutrition supplementation program, declined slightly, but significantly.

Dr. Liping Pan from the CDC...

It's common knowledge that as a country, we've been getting fatter for decades. In some states the prevalence of obesity is over 35 percent, as it is in adults over all, as shown in the graphic below.

 

Probably it's less widely known that there are at least 13 different types of cancer that are associated with overweight (BMI = 25-29.9) and obesity (BMI = or > 30), according to Dr. C. Brooke Steele of the CDC, and colleagues. These include: adenocarcinoma of the esophagus; cancers of the breast [in postmenopausal women], colon and rectum, endometrium,...

Insulin resistance is a hallmark of type 2 diabetes, and occurs in more than one type of body tissue. For example, insulin-resistant muscle will not respond normally when insulin directs it to take up glucose from the blood. And the liver of an insulin - resistant person won't stop its production and secretion of glucose into the blood as it should. As a result, blood glucose rises to abnormal, and possibly dangerous levels. In other words, a person becomes diabetic. Obesity is a major risk factor for diabetes and for insulin-resistant tissues, but how excess fat tissue causes insulin resistance isn't understood. A recent study in mice elucidates at least partially, a mechanism for how obesity instigates insulin resistance and type 2 diabetes.

Writing in the journal Cell...