Stress is more deadly for obese people than for lean ones

Researchers found that overweight people repeatedly placed in a stressful situation exhibited increasing amounts of interleukin-6, an inflmmatory marker, in their saliva.

This cytokine is secreted by T cells and macrophages to stimulate immune response, e.g. during infection and after trauma, especially burns or other tissue damage leading to inflammation. Additionally, interleukin-6 has been associated with a number of conditions for which obesity itself creates an increased risk, including atherosclerosis, type 2 diabetes, cancer and fatty liver disease.

The experiment consisted in placing subjects in stressful situations, including a very unfriendly job interview and a difficult oral math exercise. They then took saliva samples to see how the stress affected the release of inflammatory mediators.

Researchers observed that lean people started out with lower interleukin-6 levels than obese people, but all participants exhibited similar amounts of biochemical response to stress. However, when the stress situation were repeated the following day, obese people doubled the concentrations while lean people's response was similar to the previous day. Interestingly, on the second day, intrerleukin-6 concentrations in saliva correlated with body mass index.

Source: http://www.cbsnews.com/news/for-obese-stress-may-be-even-more-deadly/

Combining BMI with Central Obesity for risk of mortality in subjects with Coronary Disease

In patients with coronary artery disease (CAD), normal weight in combination with central obesity is associated with the highest risk of mortality. This is the conclusion of a meta-analysis conducted with data of 15,547 participants (mean age 66 years) with CAD who took part in 5 studies from 3 continents. 

The researchers identified 4,699 deaths in 4.7 years. After adjusting for potential confounders, the worst long-term survival was observed in the subjects with normal weight but who had central obesity. In other words: a person with a BMI below 25 kg/m², but who had a waist-to-hip ratio (WHR) of 0.98 had significantly higher mortality than a person with a similar BMI and a WHR of 0.89. More surprisingly, these people had significantly higher mortality than a person with a BMI of 30 kg/m² and WHR of 0.89 or 0.98.

Source: Journal of the American College of Cardiology

During a median follow-up of 4.7 years, the researchers identified 4,699 deaths. The worst long-term survival was observed in people of normal weight who displayed central obesity: a person with a BMI of 22 kg/m² who had a waist-to-hip ratio (WHR) of 0.98 had significantly higher mortality than a person with a similar BMI and a WHR of 0.89 (hazard ratio, 1.10); they also had significantly higher mortality than a person with a BMI of 30 kg/m² and WHR of 0.89 or 0.98 (hazard ratios, 1.61 and 1.27, respectively).

Read more at: http://medicalxpress.com/news/2013-01-cad-highest-mortality-central-obesity.html#jCp

During a median follow-up of 4.7 years, the researchers identified 4,699 deaths. The worst long-term survival was observed in people of normal weight who displayed central obesity: a person with a BMI of 22 kg/m² who had a waist-to-hip ratio (WHR) of 0.98 had significantly higher mortality than a person with a similar BMI and a WHR of 0.89 (hazard ratio, 1.10); they also had significantly higher mortality than a person with a BMI of 30 kg/m² and WHR of 0.89 or 0.98 (hazard ratios, 1.61 and 1.27, respectively).

Read more at: http://medicalxpress.com/news/2013-01-cad-highest-mortality-central-obesity.html#jCp

During a median follow-up of 4.7 years, the researchers identified 4,699 deaths. The worst long-term survival was observed in people of normal weight who displayed central obesity: a person with a BMI of 22 kg/m² who had a waist-to-hip ratio (WHR) of 0.98 had significantly higher mortality than a person with a similar BMI and a WHR of 0.89 (hazard ratio, 1.10); they also had significantly higher mortality than a person with a BMI of 30 kg/m² and WHR of 0.89 or 0.98 (hazard ratios, 1.61 and 1.27, respectively).

Read more at: http://medicalxpress.com/news/2013-01-cad-highest-mortality-central-obesity.html#jCp

Do all dietary fats increase body weight? The Olive oil case

Is it paradoxical that olive oil intake does not increase body weight? It seems so, as olive oil is an energy-dense food, frequently consumed in south European countries. These countries have increasingly high obesity prevalence, according to different international organizations, including the World Health Organization. Actually, in 2008 the New York Times published that the Mediterranean Diet had succumbed to fast food.

However, recent evidences are pointing out in the opposite direction, indicating that olive oil could be helpful against body weight gain. A cross-sectional study on 6,352 Spanish adults, published early this year, showed that olive oil intake did not affect body mass index (BMI) and the risk of obesity after adjustment for total energy intake.


Alright, but this is a cross-sectional study. ¿What happens if olive oil is administrated to a group of human subjects? The strongest evidence we have to date is the results of the PREDIMED study. This is a three-arm randomized trial aimed to assess the effects of Mediterranean Diet in primary cardiovascular prevention in more than 7000 individuals at high cardiovascular risk. A substudy of the PREDIMED trial showed that increased adherence to the Mediterranean Diet, with 1L per week of olive oil, was inversely associated with diabetes incidence, which occurred in the absence of significant changes in body weight or physical activity.

It has been even suggested that olive oil intake, as part of a Mediterranean Diet, is inversely associated with BMI and obesity in adults and children. Therefore, it might not be the excess of fat from olive oil intake what is causing the epidemic of obesity in Southern Europe, but as the New York Times suggested, but the retreat of the traditional diet of the region.

Another way to measure obesity

Traditionally, Body Mass Index (BMI) has been used to measure obesity. Now, scientists propose a novel method that includes waist circumference (WC) in addition to BMI, providing better information about the risk of premature death for an individual. Known as A Body Shape Index (ABSI), the metric was tested on national health and nutrition data from 14,000 adults in the United States. This new parameter is based on WC adjusted for height and weight and was found to show a better correlation with death rate than does the BMI.

Death rates increased approximately exponentially with above average baseline ABSI, whereas elevated death rates were found for both high and low values of BMI and WC. The association of death rate with ABSI held even when adjusted for other known risk factors including smoking, diabetes, blood pressure, and serum cholesterol. ABSI correlation with mortality hazard held across the range of age, sex, and BMI, and for both white and black ethnicities (but not for Mexican ethnicity), and was not weakened by excluding deaths from the first 3 yr of follow-up.

Source: PloS ONE

Weight-loss drug obtains FDA approval

After 13 suspenseful years, the US Food and Drug Administration (FDA) has approved a pill that could help to fight the US obesity epidemic.

According to the FDA, Belviq (lorcaserin) can help people to lose about 3–4% of their body weight when combined with a healthy diet and exercise. The drug has been approved for use by obese people with a body mass index (BMI) greater than 30, and for a subset of overweight people (with a BMI of more than 27) who have health conditions such as high blood pressure, elevated cholesterol and type 2 diabetes.

The FDA had already rejected Arena’s first application for approval of Belviq in September 2010 because the compound seemed to produce tumours in rats and because the company could not statistically rule out an increase in the risk of heart-valve problems. Similar to fenfluramine, Belviq suppresses food cravings by mimicking the effects of serotonin in the brain, making people eat less and feel full. However, Belviq seems to activate only the serotonin 2C receptor in the brain, not the serotonin 2B receptor that is present in heart muscle.

The FDA’s turnaround this week came after Arena performed echocardiograms in nearly 8,000 people to measure heart-valve function, which revealed that there was no increase in heart-valve abnormalities among those taking the drug. The firm has agreed to run six post-marketing studies, including a long-term cardiovascular trial, and patients with congestive heart failure are advised not to take the drug.

Source: Nature (doi:10.1038/nature.2012.10923) http://www.nature.com/news/weight-loss-drug-wins-us-approval-1.10923

Doctors need to be honest with their patients and say ‘Your kid’s overweight’

According to a study published online in Archives of Pediatrics & Adolescent Medicine, doctor should tell parents when their children are overweight as this would improve their motivation to follow healthy eating and activity.

Perrin and co-authors Asheley Cockrell Skinner, and Michael J. Steiner, performed a secondary statistical analysis of data collected from 4,985 children ages 2 to 15 years old who had a body mass index (BMI) at or above the 85th percentile based on measured height and weight. The data were collected as part of the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2008.

During that time, only 22 percent of parents reported that a doctor or other health professional told them their child was overweight. This percentage increased from 19.4 percent in 1999 to 23.4 percent in 2004, and then to 29.1 percent in 2007-2008. Even among parents of very obese children, only 58 percent recall a doctor telling them.

However, as shown in the journal Pediatrics parents are reluctant to be told that their children have an unhealthy weight.

Source: http://www.sciencedaily.com/releases/2011/12/111205165122.htm

Are diet and exercise enough to lose weight and keep it low?

A new study, published in The New England Journal of Medicine, shows that regaining weight after a period of diet and exercise may be inevitable due to hormones.

Australian researchers found that after losing weight, hormone levels - particularly those that influence hunger - shifted in the body, leading to increase appetites and weight regain.

The study involved 50 adults with a body mass index (BMI) between 27 and 40, who were on a diet and exercise for 10 weeks. After an initial loss scientists found that the levels of appetite-regulating hormones changed, resulting in a regain of 1/3 of the lost weight over the course of a year.

The results of the Australian study corroborate findings in another paper released earlier this year, in which researchers from Spain confirmed that people with high levels of the hormone leptin and low levels of ghrelin are more likely to gain the weight they lost.

Instead of playing the diet and exercise message on repeat - an ineffective longterm weight loss strategy for some - the Spanish authors suggested that endocrinologists and nutritionists consider the possibility of hormonal imbalances when developing weight loss strategies.

Source: http://www.nydailynews.com/life-style/health/diet-exercise-fight-obesity-study-article-1.971052#ixzz1cjDgPJ3S

BMI may not be the right tool to measure health risks

The BMI is easy to measure, cheap to compile and track, and simple to convey to patients, but it was never meant to be a predictor of an individual's health risks. It was intended as a useful metric to track changes in the health and nutrition of large populations. For patients who are very muscular, and for African Americans, BMI is often a poor gauge of body composition. For Asians and people who are sedentary but slim, a reliance on BMI can lead a physician to overlook signs of elevated disease risk. A child's BMI, which is calculated differently than that of an adult, is also an imperfect predictor of illness or early death.

The BMI continues to dominate research on obesity and guide physicians' advice to patients. But some researchers have launched a rear-guard effort to knock the measure from its place atop the public-health pedestal. To replace — or at least supplement — the BMI, they are searching for measures that might offer individual patients a better gauge of their health risks, as well as a wider range of options to better their odds of staying healthy.

They'll also need tools to do so that are as cheap and simple as the BMI. Most techniques that measure body composition, including the Bod-Pod, the dual-energy X-ray absorption test (DEXA), and hydrostatic underwater weigh-in, are costly and time-consuming. Bioelectrical Impedance Analysis, an inexpensive and reliable gauge of body composition increasingly used in weight-management programs, may be practical in some general medical practices. But researchers are increasingly looking for ways to capture such information with tools as simple and inexpensive as tape measures.

One of the easiest alternatives to the BMI is waist measurement. With growing evidence that fat girdling the waist and visceral organs disturbs metabolism, the circumference of a patient's midsection has been shown to be a better predictor of Type 2 diabetes risk than the BMI.

Finally, an increasing number of researchers cite a major gap in the BMI: its inability to reflect the health effects of an individual's exercise habits. At least seven high-profile studies in the last decade have established that even for people with high BMIs, cardiovascular risk and the likelihood of early death are driven down significantly by maintaining a high level of fitness or at least regular physical activity. The risk of Type 2 diabetes also falls, although in that case, studies suggest that whittling waist circumference is a better strategy still.

Source: L.A. Times

BMI in adolescence, a substantial risk factor for obesity-related disorders

What you weigh in your teen years can have far-reaching effects on your heart health in the future, suggests new research.

The higher your body mass index (BMI) in your late teens, even if it is well within the normal range, the greater your risk of heart disease decades later, according to a large study published in the April 7 issue of the New England Journal of Medicine.

For every one unit increase in BMI in the teen years, the study found a 12 percent increase in the risk of heart disease around 20 years later. And, for every one unit increase in BMI, the study found a nearly 10 percent increase in the risk of type 2 diabetes, though this risk may largely be related to a higher BMI in adulthood as well.

Data for the study came from a large group of young men entering the Israeli army. The researchers followed 37,674 males from the time they were first examined for military service at the age of 17, until an average of 17.4 years later, according to the study.

Overall, men with the highest BMIs in their teens were 2.76 times more likely to develop type 2 diabetes and 5.43 times more likely to have coronary heart disease later in life compared to those with the lowest BMIs, reported the study.

However, when a normal adult BMI was factored into the analysis, the increased risk of type 2 diabetes disappeared, suggesting that weight in adulthood is far more of a risk factor for the development of type 2 diabetes than weight status in your teens.

But, the researchers found that the risk of heart disease was elevated whether or not someone was heavy in their teens or heavy as an adult, suggesting that extra weight at any age affects cardiovascular health.

Education on healthy lifestyle factors should start as early as possible in schools and at home, he said. Parents should make healthy eating and exercise part of the family routine. And, he said, it's important to start as early as possible.

Source: Serena Gordon, Health Day. 

Cannabis use and obesity. Can it be protective?

The American Journal of Drug and Alcohol Abuse has just published a follow-up study on the relationship between cannabis and obesity in young adults.

The authors, who examined the data of cannabis consumption and BMI for 21 years, found that 50.9% of young adults reported use of cannabis in the last month or year and 34.1% had BMI ≤ 25. Multivariate analysis showed that those who had used cannabis were less likely to be categorised in the BMI ≥ 25 group with the least prevalence of overweight/obesity being observed in every day cannabis users. 

Therefore, they concluded that there is a lower prevalence of overweight and obesity among young adult cannabis users. However, they also admit athat further research is needed to examine the mechanism of this association.