Media ReleaseFrom: European Congress on Obesity
The obesity paradox: large study finds people hospitalised for infections are twice as likely to survive if they are overweight or obese
A study of more than 18,000 patients in Denmark, presented at this year's European Congress on Obesity in Vienna, Austria (23-26), shows that patients admitted to hospital for treatment for any infectious disease are around twice as likely to survive if they are overweight or obese. This research on the so called 'obesity paradox' is by Sigrid Gribsholt, Aarhus University Hospital Department of Clinical Epidemiology, Denmark, and colleagues.
The association between body mass index (BMI) and mortality remains controversial. From an evolutionary perspective, obesity and associated proinflammatory defences may protect against death from infections. In this new study, the authors examined the impact of body-mass index on outcome after any acute incident hospital admission for infection in a population-based study.
The study team identified 35,406* persons with an incident acute medical or surgical inpatient admission for an infectious disease during 2011-2015 in the Central Denmark Region. They examined risk of death within 90 days after discharge date in association with underweight, overweight and obesity, versus normal weight as reference. They adjusted for potential confounding factors, and examined the influence of recent weight change, comorbidities, cancer, and tobacco smoking on the association between BMI and mortality.
Compared with patients of normal weight, the adjusted risk of death following infection was 2.2 times higher in patients with underweight. However, no mortality increase was observed among patients with stable underweight, i.e., no recent weight loss which could indicate other health problems. In contrast, patients with overweight were 40% less likely to die and those who were obese 50% less likely to die than those of normal weight.
Among patients with obesity, presence or absence of recent weight changes, comorbidities, cancer, or smoking had little effect on the association with decreased mortality.
The authors conclude: "Overweight and obesity were associated with substantially reduced 90-day mortality following incident hospital admission for infection. An association between underweight and increased mortality was confined to patients with recent weight loss, suggesting confounding by other hidden disease."
Obese and overweight patients hospitalised with pneumonia are 20-30% less likely to die than normal weight patients
New research from over 1000 US hospitals* presented at this year's European Congress on Obesity in Vienna, Austria, shows that obese and overweight patients hospitalised for pneumonia are 20-30% less likely to die than patients of a normal weight. The study is by Professor Shy-Shin Chang and Dr Yu-Jiun Lin, Taipei Medical University Hospital, Taipei City, Taiwan, and Dr Jon Wolfshohl, Department of Emergency Medicine, John Peter Smith Hospital, Fort Worth, TX, USA, and colleagues.
Obesity prevalence is increasing steadily throughout the world's population in most countries and pneumonia is one of the most common infectious diseases; however, there is uncertainty about an inverse relationship between obesity and pneumonia mortality. A previous meta-analysis** has shown that an 'obesity survival paradox' exists for pneumonia (where obese people had better survival), but high variability existed among these studies. This study aimed to determine the impact of being overweight and obese on pneumonia patients, by using data from almost 1.7 million patient episodes of pneumonia across 1000 hospitals in the USA.
Using the Nationwide Readmission database of the US from 2013 to 2014, the authors identified patients hospitalised with pneumonia. A pneumonia-associated hospitalisation was defined as one in which the discharge record listed a principal diagnosis of pneumonia or a secondary diagnosis of pneumonia if the principal diagnosis was respiratory failure or sepsis. Use of mechanical ventilation was used to stratify pneumonia of different severity. Hospitalized pneumonia patients were categorized into normal (body mass index [BMI] under 25), overweight BMI between 25 and 30), and obese (BMI over 30).
To minimise baseline differences between patients with different body weight, the authors carried out a technique call propensity score (PS)-matched analysis. PS contains 41 variables including demographics, social economic status, chronic comorbidities, and severity of pneumonia. Patients were matched 1:1:1 using this technique across the three groups of normal weight, overweight and obese. The authors then used computer modelling on the PS-matched pairs to assess the association between body weight and 30-day in-hospital mortality.
A total of 1,690,760 pneumonia hospitalisation episode fulfilled the inclusion criteria, of which 17,992 were overweight, 195,889 were obese, and 1,476,879 were normal weight. Compared with normal weight patients without use of ventilator, overweight patients were 23% more likely to survive and obese patients 29% more likely to survive. Similar results were obtained in the cohort of more serious pneumonia requiring the use of ventilator - overweight and obese patients were 21% and 30% respectively more likely to survive than normal weight patients (see table 1 full abstract).
To investigate whether there was a differential risk of 30- day mortality among different obese populations, the authors stratified patients into different subgroups and adjust the risk for mortality using PS score (see Figure 1 full abstract). Although the survival benefit of obesity is consistent in all subgroups, patients with lower comorbidity burden/severity had substantially better survival. For example, being in the lowest comorbidity quartile compared with the highest is associated with 53% improvement in survival, and being in the group with the lowest severity of pneumonia was associated with 67% improvement in survival compared with the highest severity.
The authors conclude: "Using a large and nationally representative sample of over 1,000 hospitals in the US, we found that increase in body mass index was significantly associated with improved survival in patients hospitalised with pneumonia. We also found that severity and comorbidity burden had a modifying effect on survival."
Nationwide USA data shows that overweight and obese patients are less likely to die from sepsis in hospital than patients with normal weight
Data from 3.7 million hospital admissions for sepsis from 1,000 US hospitals*, presented at this year's European Congress on Obesity in Vienna, shows that patients who are overweight or obese are more likely to survive than those who are normal weight. The study is by Dr Yu-Jiun Lin, Taipei Medical University Hospital, Taipei City, Taiwan, and Dr Jon Wolfshohl, Department of Emergency Medicine, John PeterSmith Hospital, Fort Worth, TX, USA, and colleagues.
About 25 % of adults admitted to intensive care units in the United States(US) have overweight and obesity, and sepsis is a common cause for admission. Although obesity reduces overall lifespan, it is unclear whether it also impacts the outcome of critically ill patients in general, or with sepsis specifically. Previous studies have delivered mixed results on mortality rates of patients of patients in intensive care based on their weight.
In this new research, the authors determined the impact of being overweight and obese on sepsis patients. Using the Nationwide Readmission database of the US from 2013 to 2014, they identified patients hospitalised with sepsis. Hospitalised patients with sepsis were categorised into normal, overweight (BMI ?25 and <30), and obese (BMI ?30). To minimise baseline imbalance between patients with different body weight, we carried out PS-matched analysis, using 1:1:1 PS matching technique. PS contains 41 variables including demographics, social economic status, chronic comorbidities, and severity of sepsis.
Computer modelling was then used to estimate the association between body weight and 30-day in-hospital mortality. A total of 3,712,764 sepsis hospitalisation episodes fulfilled the inclusion criteria, of which 52,101 were overweight, 511,140 were obese, and 3,149,523 were normal weight.**
Compared with normal weight patients, overweight patients were 23% less likely to die and obese patients 22% less likely to die from admission to hospital for sepsis. 30-day readmission rate were also slightly lowered for overweight and obese patients, but total cost of hospital stay were highest in obese patients (see abstract table 1)
To investigate whether there was a differential risk of 30-day mortality among different obese populations (based on income, type of infection, and severity of sepsis). However, the effect of obesity on mortality was consistent among these different subgroups.
The authors conclude: "Using a large and nationally representative sample of over 1,000 hospitals in the US, we found that increase in BMI was significantly associated with improved survival and lowered readmission among hospitalized patients with sepsis. Our results suggest that BMI may be used for risk stratification of patients with sepsis."
Less muscle wasting in obese people in intensive care may mean they have a better chance of survival
Further evidence that obese people who are seriously ill could have a better chance of survival than their normal weight counterparts is presented at this year's European Congress on Obesity in Vienna, Austria (23-26 May).
The study, by Jeroen Molinger. Erasmus MC, University Medical Center Rotterdam, Netherlands, and colleagues suggests that obese people could potentially have a better. chance of survival during intensive care stay because the extra weight causes an adaptive response of the muscle, which in turn results in higher muscle quality; and lower rates of damaging muscle wasting.
While obesity and overweight are associated with an increased risk of death in the general population, a decrease in mortality has been reported in specific disease conditions. This so called 'obesity paradox' of critical illness refers to better survival with a higher body mass
Hyper-catabolism - the body breaking itself down - in the acute phase of the critical illness is presumed to be an adaptive response providing the essential fuel for energy production in vital organs. However, when this hypercatabolic state persists it may result in muscle wasting and muscle weakness. Skeletal muscle quality is recognised as a marker of function in healthy individuals and critically ill patients. To determine muscle histology on an ICU; a muscle biopsy is normally needed. However, this procedure is invasive and does not give a result of the whole muscle. In this new study, by using a new non-invasive ultrasound technology, assessment of muscle histology and morphology, the authors aimed to study muscle quality in obese and non-obese critically ill patients.
In the total group of 26 patients, nine were defined as obese by a body mass index higher than 30kg/m2. In this obese subgroup, the wasting patterns were distinctly different than the non-obese group, when comparing sepsis and neurotrauma. The obese group had a higher muscle quality index corrected by muscle thickness in regard to the non-obese. The speed of wasting, as defined in decline in muscle quality, was also lower in the first 4-5 days in the obese group in comparison with the non-obese.
The authors conclude: "Critically ill patients with obesity seem to have higher muscle quality, as measured by ultrasound at the point of admittance to intensive care compared to non-obese patients. This might be the metabolic protective shield also described as the 'obesity paradox'."
What your choice of clothing says about your weight
It's commonly said that you can tell a great deal about a person by the clothes they wear. Now new research suggests that choice of garment colour is a predictor of body mass index (BMI).
The findings being presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May) reveal that darker and multicolour clothes are preferred by women with higher BMIs, while men with larger BMIs are more likely to choose black or white garments.
Colour plays an important role in influencing moods and emotions, and previous research suggests that the colour of the clothes you wear says a lot about your personality, mood, and even how other people perceive you. The size and colour of the clothing you choose depends on a variety of personal factors, and these may include perceived or actual overweight or obesity.
To investigate this further, Dr Charoula Nikolaou and Professor Stuart Gilmour from St Luke's International University in Tokyo, and Professor Mike Lean from the University of Glasgow's School of Medicine, examined the relationship between BMI and the size and colours of clothes purchased from a global online retail service.
Between October and December 2017, data on body weight and height, clothing size, and colour were collected from over 34,000 customers who completed feedback forms. The data, publicly available online, was taken from the AliExpress website, part of the Alibaba group, the China-based multinational e-commerce site. Countries from which the orders were made were grouped by income: low-income, lower-middle income, upper-middle income, and high-income. Clothing colours were also grouped by dark, light, metal, pastel or print colours.
Over a two-month period (covering different seasons in different countries), 27,083 women (8,119 skirts and 18,964 dresses) and 7,295 men (7,295 trousers) from 119 countries purchased items of clothing from 26 clothing brands. Most were purchased by people living in high- and upper-middle income countries. Online sales were mostly to young and middle-aged customers. Over half of trousers sold, almost a quarter of dresses, and 15% of skirts were purchased by someone overweight or obese (BMI>25kg/m2).
The association between customers' BMI and size and colour garments was estimated using linear regression, a form of statistical modelling which adjusts for potential factors that could influence the relationship such as gender, country of origin, income of country of origin.
Results showed that clothing size was closely related to both BMI and waist circumference. Women with a higher BMI were more likely to buy black/blue/dark colour and floral dresses, and multicolour and dot-patterned skirts. Whilst men with a higher BMI tended to stick to black or white trousers.
The authors acknowledge that their findings show observational differences which are not necessarily evidence of cause and effect. They conclude: "Our study suggests that the size and colour of garments purchased can be indicators of weight problems. Online clothing purchase choices could be used to target non-judgemental messages about weight-management and preventing unwanted weight gain."
The authors say that two practical actions to help people with weight-management or preventing weight-gain could result from this study:
· Clothing size is a reliable indicator of BMI so non-judgemental messages about weight-management could be provided with purchases of large size-garments
· Advice for people who have successfully lost weight could include changing the wardrobe to smaller size garments and switching to colours and patterns favoured by thinner people and which more overweight people tend to avoid.
Study suggests that a novel wearable nasal device to reduce smelling ability can induce weight loss and changes to dietary preferences
New research presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May) shows that a daily use of a novel nasal device to reduce smelling ability can induce weight loss and changes to dietary preferences in people aged 50 years and under. The study was conducted by Dr. Dror Dicker, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel and colleagues.
Food odours and our sense of smell can have a significant influence on how much we eat as well as our dietary preferences. There has been extensive study into the role of olfaction (smell) in regulating appetite, food intake, and body weight, but the mechanisms involved are so complex that we have only begun to understand this system. We know that exposure to food odours increases how much we eat, while loss of smell may lead to reduced food intake.
Being overweight or obese can actually sometimes reduce our sense of smell, but overweight and obese people have also been found to have a greater sensitivity to food smells and higher stimulation of their appetite when exposed to food odours which leads them to eating larger portions of food. Olfaction declines as we age, typically beginning around the age of 50. No studies up to now have deliberately reduced the ability to smell and observed its effect on weight loss in human subjects.
The authors conducted a pilot study to determine if a soft silicone nasal insert (Beck Medical, Israel) could be used by obese subjects to reduce their ability to smell, with a resulting reduction in body weight, a change in dietary preferences, and an improvement in metabolic dysfunction. 65 obese adults completed the trial, device group (37) and control group (28). The participants in the study group wore the novel nasal insert daily, and those in the control group inserted "placebo" drops of saline into each nostril daily. All participants were put on a diet with a 500 calorie per day deficit from their regular diet, and follow-up visits occurred every two weeks. Measurements of each subject's weight, olfactory sensitivity, as well as glucose, insulin, and lipid levels were made at the start and end of the study period.
The study found that the nasal device worked as planned, causing a significant drop in olfactory sensitivity, while the placebo saline drops had no effect. Participants in both groups lost weight but when considering the research group as a whole, there was not significant difference in the amount of weight lost by those who used the device compared to the control group.
However, analysis of the results according to whether the subject's age was above or below 50 years, found that among participants ages ?50 years, weight loss in the nasal device group was significantly greater than in the control group (7.7% of body weight in device vs. 4.2% in control). In addition, dietary preferences for sugar, artificial sweeteners, and sweet beverages were significantly reduced in device relatively to control for the whole population and primarily for those age ?50. Furthermore, Insulin levels for the whole population reduced significantly in device group from beginning to end of the trial, while no significant difference occurred in control.
The team conclude: "This novel smell-reducing self-administered nasal device caused weight loss in subjects aged ?50 years and reduced dietary preference for sweet food for all participants,". They add: "Further studies should be conducted to explore this new option and to determine the role of this device for treatment of obesity and diabetes".
The wearable nasal insert is planned to be commercially available within few months, and will be marketed under the name NozNozT as a non-medical wellness device, while additional medical research is planned to further support its clinical future use.
Unsubstantiated health claims widespread within weight loss industry
New research investigating the legality of on-pack nutrition and health claims routinely found on commercially available meal replacement shakes for sale in the UK, reveals that more than three-quarters are unauthorised and do not comply with the EU Nutrition and Health Claims regulation.
This is one of the first studies to analyse how on-pack claims stack up to current regulation, and how much consumers actually understand and are influenced by such claims, and is being presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May).
Britain is the most obese nation in Western Europe, with rates rising faster than any other developed country. The Organisation for Economic Co-operation and Development (OECD) estimates that almost two-thirds (63%) of UK adults are overweight or obese, making the UK weight-loss market a ?26 billion business. In Europe, sales of meal replacement products are estimated to reach ?940 million by 2020.
'Meal replacement for weight control' products are simple, convenient and low in calories, and there is good evidence that they are an effective option for weight loss and weight maintenance. Their nutritional composition, labelling, and nutrition and health claims are governed by EU legislation which seeks to ensure that the products are nutritionally sound and that any reported benefits are clear, accurate, and based on scientific evidence.
In this study, Dr Kelly Johnston and colleagues from LighterLife and Kings College London in the UK analysed the nutrient composition, legal compliance, and consumer understanding of on-pack health and nutrition claims for all commercially available 'meal replacement for weight control' shakes sold in the UK in 2017. On-pack information was assessed for its compliance with composition, labelling, and nutrition and health claims in line with EU regulation.
The researchers found that only 10 of the brands provided enough information to demonstrate that they met all the EU compositional and labelling requirements and the majority of products did not meet the basic compositional criteria necessary to be called a 'meal replacement for weight control'.
Results also showed that more than 90% of products made at least one nutrition claim on pack and just over half made at least one health claim-yet 79% of these claims were not compliant with EU regulations.
In order to gauge their understanding of on-pack nutrition and health claims, internet-based questionnaires were completed by volunteers who were currently or had recently been engaged with the LighterLife weight loss programme. Of 240 respondents (44 men), three quarters (75%) reported being on a diet within the last 6 months.
The claims most likely to be reported as being understood by responders included common weight loss messages such as "low fat" (95%), "low calorie" (95%), and "high protein" (94%). In contrast, only around half of those questioned understood the claims: "protects against chronic diseases" (48%) and "low GI" (53%) - neither of which are authorised, nor should be on pack.
Interestingly, despite a relatively high overall reported level of understanding of on-pack claims, the majority of claims were perceived as being false.
Dr Johnston concludes: "Manufacturer's misleading labelling is confusing consumers about the healthiness and nutritional quality of meal replacement shakes. Some of these claims are clearly exaggerated and many are simply untrue. What we see from this group of consumers is that they generally have false perceptions about the efficacy of such products. In other words, even if they understand the claims, they often don't believe what they are reading."
She adds: "This situation doesn't benefit anyone but what it does mean is that reputable providers are disadvantaged by unscrupulous parties who sell products not fit for purpose. This study highlights the need for better enforcement to ensure products for sale meet the legally required compositional and labelling criteria which will both protect consumers whilst ensuring fair market competition."
The authors note that they only looked at one type of product-single serve meal replacement shakes-which is not representative of the entire sector.
Milk and dairy do not promote childhood obesity according to comprehensive new review
A comprehensive review of the scientific evidence over the last 27 years concludes that cow's milk and other dairy products do not play a role in the development of childhood obesity. The research being presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May) also found no "underlying mechanistic rationale" to support the theory that milk and dairy products promote excess weight gain or increase appetite.
"An important finding was the consistency of findings across different types of milk and dairy products and age groups," explains Dr Anestis Dougkas, Institut Paul Bocuse, Ecully, France who led the research.
"Our results should alleviate any concerns that parents may have about limiting their children's consumption of milk and dairy products on the grounds that they might promote obesity."
It's well known that dairy products such as milk, yogurt, and cheese are nutrient rich foods which provide many essential nutrients throughout life. Previous reviews have shown that milk and dairy are not associated with childhood obesity. But whether milk and dairy promote obesity in children continues to be hotly debated, and public health advice about how much milk and dairy children need, and when to stop having it, remains unclear.
To investigate this further, Dr Anestis Dougkas from the Institut Paul Bocuse in France and colleagues analysed data from 43 cross sectional studies, 32 longitudinal cohort studies, and 20 randomised trials examining the effects of both full and low fat milk and other dairy product intake on obesity in childhood between January 1990 and June 2017. They also examined the possible mechanisms underlying the effect of different milk and dairy products on body-weight regulation.
Analysis of 95 trials involving 203,269 individuals showed that milk and dairy products were not associated with body fatness in children. The researchers found no evidence to suggest that body fatness varied by type of milk or dairy products, or with age of the children. However, they acknowledge a lack of data in children aged 1 to 5 years old. Only nine studies, of which two assessed milk proteins as components of dairy, found a positive association between milk and dairy products and body fatness.
Although the authors note no precise effect size, they conclude: "There is no harmful effect on obesity from incorporating dairy and especially milk in the diet of children and adolescents. These results call into question current recommendations that restrict consumption of milk and dairy products. The new and emerging range of products (including plant-base alternatives being used as dairy milk substitutes) have yet to be evaluated in scientific studies."
The authors note some limitations, including that they did not look for literature in other languages than English and did not assess the quality of the studies. However, their paper is the first to combine results across many studies making it a valuable reference that can be used to update existing nutritional guidelines around milk and dairy consumption in children.
Study suggests obese children who consume recommended amount of milk at reduced risk of metabolic syndrome
But majority of children with obesity consume less than advised 2-3 cups of milk a day
"Our findings indicate that obese children who consume at least the daily recommended amount of milk may have more favourable sugar handling and this could help guard against metabolic syndrome", says author Dr Michael Yafi from McGovern Medical School at The University of Texas Health Science Center, Houston, USA. "Worryingly, only 1 in 10 young people in our study were consuming the recommended amount of milk."
Metabolic syndrome is defined as the presence of at least three of five conditions that increase the risk of diabetes, heart disease, and stroke - high blood pressure, high levels of blood sugar or triglycerides, excess belly fat, and low "good" cholesterol levels. At least a third of Americans are thought to have metabolic syndrome, while one in three American children and teens are overweight or obese.
Previous studies have shown that milk protects against metabolic syndrome and diabetes in adults, but studies investigating the effect of milk consumption on metabolic health and metabolic syndrome risk factors in obese children are scarce.
To investigate this further, Dr Yafi and colleagues assessed daily milk intake and its association with fasting insulin levels-the hormone that stabilises blood sugar and a biomarker for metabolic syndrome risk-in obese children and adolescents attending a paediatric weight management clinic. A high insulin level is a sign of insulin resistance or prediabetes, and can also signify metabolic syndrome.
They conducted a retrospective chart review of 353 obese children and adolescents aged 3 to 18 years between December 2008 and December 2010. Information on fasting serum insulin was available for 171 children at their first visit. The research team also recorded information on daily milk intake, milk types, daily fruit juice and other sugary drinks intake, fasting blood glucose, and insulin sensitivity. They used an upper normal level of fasting insulin (19 microunits per ml; uiu/ml) to link the results to insulin resistance.
Over half of the participants were male, three quarters were Hispanics, and had an average age of 11.3 years.
On average, just one in ten children (13%; 23/171) reported drinking the daily recommended milk intake of three cups or more. Girls reported drinking less milk than boys, but no difference in intake was noted by ethnicity.
The American Academy of Pediatrics and the 2015 Dietary Guidelines for Americans advise two to three cups of low fat (1% or 2%) milk a day for children over the age of two.
The study also found that under half (44%) of children who reported drinking less than one cup a day had fasting insulin levels of less than 19 uiu/ml, compared to almost three-quarters (72%) of children who reported drinking more than two cups a day.
Overall, children who drank less than one cup of milk each day had significantly higher levels of fasting insulin (median 23 uiu/ml) than those who drank less than two cups a day (15 uiu/ml), or at least two cups a day (13 uiu/ml).
After adjusting for other aspects that might affect insulin levels including race, ethnicity, gender, level of physical activity, sugary drinks intake, glucose levels, and type of milk based on fat content, the researchers found lower fasting insulin levels among children who drank at least two cups of milk a day. No association was noted between milk intake and blood glucose or lipid levels.
Dr Yafi concludes: "Many studies have linked sugary drinks to childhood obesity. In contrast, our pilot study suggests that milk intake is not only safe but also protective against metabolic syndrome. We should encourage our children, especially those with obesity who are at higher risk of insulin resistance and poor glycaemic control, to consume the recommended daily amount of milk."
The authors acknowledge that their findings show observational differences rather than cause and effect. They point to several limitations, including the small sample size, and that the study includes mainly Hispanic children making the generalizability of the findings to other ethnicities uncertain.