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Tag: body mass index (BMI)

Published on Leave a comment on Low Fitness Is Associated With Larger Waist Size and Higher Levels of Inflammation

A new study's results actually made me ask - this was a surprise? Of course more fit people have lower levels of chronic inflammation and smaller waist size, no matter their Body Mass Index (BMI) - which includes their weight. And the reverse is also true (lower fitness levels are associated with greater waist size and higher levels of chronic inflammation, no matter the BMI). Which means that being fit, no matter the weight, has health benefits. From Medical Xpress:

Low fitness is associated with larger waist size and higher degree of inflammation

Low fitness is associated with a larger waist size and a higher degree of inflammation, according to a study published January 17, 2018 in the open-access journal PLOS ONE by Anne-Sophie Wedell-Neergaard from the University of Copenhagen, Denmark, and colleagues.

Waist circumference can indicate the amount of excess fat found around the abdomen and previous studies have shown excess abdominal fat may increase the risk of chronic system inflammation and metabolic diseases. The authors of the present study sought to investigate the association between fitness and waist circumference as well as the association between fitness and low-grade inflammation, and whether there was a correlation with Body Mass Index (BMI).

The researchers analyzed the previously collected data of 10,976 individuals from The Danish National Health Examination Survey 2007-2008. These individuals took a maximal oxygen uptake (VO2max) test to assess their physical fitness. Their waist circumference, weight and height were measured, and blood samples were taken to measure their level of C-reactive protein, a nonspecific biomarker of low-grade inflammation.

The researchers found that higher levels of fitness were associated with a smaller waist circumference and a lower degree of inflammation independently of BMI. The researchers acknowledge that there are possible limitations that may affect the findings of the study, but overall the results suggest that increased fitness has the potential to reduce abdominal fat mass and inflammation which may improve metabolic health irrespective of BMI. 

Published on Leave a comment on Being Overweight In Midlife and Higher Risk of Dementia

Interesting study results - being overweight (a higher body mass index or BMI) is linked to dementia more than 20 years later, but in the few years before dementia onset body mass index (BMI) is lower in those who develop dementia than in those who don't develop dementia. The researchers hypothesize that 2 processes are going on:  A higher BMI (overweight or obese) in mid-life is harmful (a direct effect), and then there is weight loss during the preclinical dementia phase. Bottom line: best is a normal weight in mid-life to try to prevent dementia later on in life. From Science Daily:

Obesity increases dementia risk

People who have a high body mass index (BMI) are more likely to develop dementia than those with a normal weight, according to a new UCL-led study. The study, published in the Alzheimer's & Dementia journal, analysed data from 1.3 million adults living in the United States and Europe. The researchers also found that people near dementia onset, who then go on to develop dementia, tend to have lower body weight than their dementia-free counterparts.

"The BMI-dementia association observed in longitudinal population studies, such as ours, is actually attributable to two processes," said lead author of the study, Professor Mika Kivimäki (UCL Institute of Epidemiology & Health). "One is an adverse effect of excess body fat on dementia risk. The other is weight loss due to pre-clinical dementia. For this reason, people who develop dementia may have a higher-than-average body mass index some 20 years before dementia onset, but close to overt dementia have a lower BMI than those who remain healthy."

In this study, researchers from across Europe pooled individual-level data from 39 longitudinal population studies from the United States, the United Kingdom, France, Sweden, and Finland. A total of 1,349,857 dementia-free adults participated in these studies and their weight and height were assessed. Dementia was ascertained using linkage to electronic health records obtained from hospitalisation, prescribed medication and death registries.

A total of 6,894 participants developed dementia during up to 38 years of follow-up. Two decades before symptomatic dementia, higher BMI predicted dementia occurrence: each 5-unit increase in BMI was associated with a 16-33% higher risk of this condition (5 BMI units is 14.5 kg for a person 5'7" (170 cm) tall, approximately the difference in weight between the overweight and normal weight categories or between the obese and overweight categories). In contrast, the mean level of BMI during pre-clinical stage close to dementia onset was lower compared to that in participants who remained healthy. [Original study.]

Published on Leave a comment on Is ‘Fat But Fit’ A Myth?

Is "fat but fit" a myth or true? The results of this study suggest that it is a myth. That there is a higher risk of coronary heart disease, and even if everything looks OK initially, it is associated with an eventual metabolic changes (and problems). Just wait a while - as can be seen in the results of this study that followed people from 8 European countries over many years (about 12.2 years). The study found that being normal weight and fit is best, and that "metabolically healthy" obese people were more likely to go on to develop metabolic abnormalities (and become metabolically unhealthy obese people) over the years. Metabolically unhealthy signs included high blood pressure, low HDL-cholesterol, and hyperglycemia (high blood sugar).

Bottom line: aim for normal weight for a lower risk of heart disease (and of course, be physically active and eat a healthy diet - fewer processed foods, and more fruits, vegetables, whole grains, seeds, nuts, and legumes). From Science Daily:

'Fat but fit' are at increased risk of heart disease

Carrying extra weight could raise your risk of heart attack by more than a quarter, even if you are otherwise healthy.Researchers have found that being overweight or obese increases a person's risk of coronary heart disease (CHD) by up to 28 per cent compared to those with a healthy body weight, even if they have healthy blood pressure, blood sugar and cholesterol levels.The findings add to a growing body of evidence that suggests being 'fat but fit' is a myth, and that people should aim to maintain a body weight within a healthy range.  ...continue reading "Is ‘Fat But Fit’ A Myth?"

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Yup, according to a new mega-study, being overweight or obese is linked to higher risk of dying prematurely than being normal weight.  And the more you weigh, the greater the risk. This mega-study that looked at data from many studies and countries, also found that being underweight is linked to a higher risk of premature death. What's the best weight to be? A BMI of 22.5-<25 kg/m2 is considered a healthy weight range, and had the lowest mortality risk in the study. Being overweight was linked to higher rates of death from "all causes", and also from 4 major causes: coronary heart disease, stroke, respiratory disease, and cancer.

However, note that while other studies also agree that being underweight or obese increases the rate of dying prematurely, there is still some debate over whether being just overweight with BMI 25–<30 kg/m2 , really has a higher risk of dying prematurely. This was pointed out in the accompanying editorial in the journal Lancet (but not mentioned below). From Science Daily:

As overweight and obesity increase, so does risk of dying prematurely: Major study

Being overweight or obese is associated with a higher risk of dying prematurely than being normal weight -- and the risk increases with additional pounds, according to a large international collaborative study led by researchers at the Harvard T.H. Chan School of Public Health and the University of Cambridge, UK. The findings contradict recent reports that suggest a survival advantage to being overweight -- the so-called "obesity paradox."

The deleterious effects of excess body weight on chronic disease have been well documented. Recent studies suggesting otherwise have resulted in confusion among the public about what is a healthy weight. According to the authors of the new study, those prior studies had serious methodological limitations. One common problem is called reverse causation, in which a low body weight is the result of underlying or preclinical illness rather than the cause. Another problem is confounding by smoking because smokers tend to weigh less than nonsmokers but have much higher mortality rates.....Hu stressed that doctors should continue to counsel patients regarding the deleterious effects of excess body weight, which include a higher risk of diabetes, cardiovascular disease, and cancer.

For the new study, consortium researchers looked at data from more than 10.6 million participants from 239 large studies, conducted between 1970 and 2015, in 32 countries. A combined 1.6 million deaths were recorded across these studies, in which participants were followed for an average of 14 years. For the primary analyses, to address potential biases caused by smoking and preexisting diseases, the researchers excluded participants who were current or former smokers, those who had chronic diseases at the beginning of the study, and any who died in the first five years of follow-up, so that the group they analyzed included 4 million adults. They looked at participants' body mass index (BMI) -- an indicator of body fat calculated by dividing a person's weight in kilograms by their height in meters squared (kg/m2).

The results showed that participants with BMI of 22.5-<25 kg/m2 (considered a healthy weight range) had the lowest mortality risk during the time they were followed. The risk of mortality increased significantly throughout the overweight range: a BMI of 25-<27.5 kg/m2 was associated with a 7% higher risk of mortality; a BMI of 27.5-<30 kg/m2 was associated with a 20% higher risk; a BMI of 30.0-<35.0 kg/m2 was associated with a 45% higher risk; a BMI of 35.0-<40.0 kg/m2 was associated with a 94% higher risk; and a BMI of 40.0-<60.0 kg/m2 was associated with a nearly three-fold risk. Every 5 units higher BMI above 25 kg/m2 was associated with about 31% higher risk of premature death. Participants who were underweight also had a higher mortality risk.

Looking at specific causes of death, the study found that, for each 5-unit increase in BMI above 25 kg/m2, the corresponding increases in risk were 49% for cardiovascular mortality, 38% for respiratory disease mortality, and 19% for cancer mortality. Researchers also found that the hazards of excess body weight were greater in younger than in older people and in men than in women.

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Research found that more time spent standing rather than sitting is associated with improved blood sugar, fats in the blood and cholesterol levels, and replacing time spent sitting with time walking is associated with a smaller waistline and body mass index (BMI). The researchers' motto: Stand Up, Sit Less, Move More.

Activity adds up over the course of a day as Dr.Lopez-Jimenez of the Mayo Clinic points out: "A person walking while at work for two hours, standing for another four hours, and performing some daily chores at home for another hour will burn more calories than jogging or running for 60 minutes. From Medical Xpress:

Get up for your heart health and move for your waistline

More time spent standing rather than sitting could improve your blood sugar, fats in the blood and cholesterol levels, according to a new study published today (Friday) in the European Heart Journal. The study also shows that replacing time spent sitting with time walking could have additional benefits for your waistline and body mass index (BMI).

Researchers in Australia gave activity monitors to 782 men and women, aged 36-80 years, who were taking part in the Australian Diabetes, Obesity and Lifestyle Study. The monitors were capable of determining, very accurately, how long each participant spent sleeping, sitting or lying down, standing and stepping (which includes walking and running)....participants each wore an activity monitor on their thigh for 24 hours a day over a seven-day period. .

An extra two hours per day spent standing rather than sitting was associated with approximately 2% lower average fasting blood sugar levels and 11% lower average triglycerides (fats in the blood). Extra standing time was also associated with 0.06 mmol/L higher average levels of the "good" type of cholesterol, HDL, and a 6% lower average total/HDL cholesterol ratio, which indicates an improvement in the total amount of HDL cholesterol in relation to "bad" LDL cholesterol.

Replacing two hours a day of sitting time with stepping was associated with an approximately 11% lower average BMI and a 7.5cm smaller average waist circumference. In addition, average blood sugar levels fell by approximately 11% and average triglycerides by 14% for every two hours spent walking rather than sitting, while HDL cholesterol was 0.10 mmol/L higher. There was no significant effect on BMI or waistline of replacing sitting time with standing.

"However, it is important to say that not all sitting is bad; but if people can incorporate alternatives to sitting wherever possible, it may benefit their heart and metabolic health. Our message is to 'Stand Up, Sit Less, Move More'."She said the study had also produced evidence of how common standing is during the waking day. "Standing takes up nearly a third of waking hours, and among this group of participants who could choose when they sat, stood or walked, the standing had health benefits.

Published on

This study, like previous research, found an association between increased dietary fiber intake (specifically from cereal and vegetable fiber) and a reduced risk of developing type 2 diabetes. However, they did not find this link with fruit fiber, and also if the person was obese. From Medical Xpress;

Study adds to evidence that increasing dietary fiber reduces the risk of developing diabetes

New research published today in Diabetologia (the journal of the European Association for the Study of Diabetes) indicates that consuming greater quantities of dietary fiber reduces the risk of developing type 2 diabetes. In this article the authors evaluated the associations between total fiber as well as fiber from cereal, fruit, and vegetable sources, and new-onset type 2 diabetes in a large European cohort across eight countries, in the EPIC-InterAct Study.

The authors divided the study participants into four equally sized groups from lowest to highest fiber intake, and assessed their risk of developing type 2 diabetes over an average of 11 years' follow-up.They found that participants with the highest total fiber intake (more than 26 g/day) had an 18% lower risk of developing diabetes compared to those with the lowest total fiber intake (less than 19 g/day), after adjusting for the effect of other lifestyle and dietary factors. When the results were adjusted for body mass index (BMI) as a marker of obesity, higher total fiber intake was found to be no longer associated with a lower risk of developing diabetes, suggesting that the beneficial association with fiber intake may be mediated at least in part by BMI.

When the authors evaluated the different fiber sources, they found that cereal fiber had the strongest inverse association: those with the highest levels of cereal and vegetable fiber consumption had a 19% and 16% lower risk of developing diabetes respectively, compared with those with the lowest consumption of these types of fiber. Again, these associations disappeared when the results were adjusted for BMI. By contrast, fruit fiber was not associated with a reduction in diabetes risk. Cereals accounted for 38% of the total fiber intake, and were the main source of fiber in all the countries involved in the study (with the exception of France where vegetables were the main source).

The authors also undertook a meta-analysis, where they pooled the data from this EPIC-InterAct study with those from 18 other independent studies (eight in the United States, four in Europe, three in Australia, and three in Asia). The meta-analysis included over 41,000 new-onset cases of type 2 diabetes and found that the risk of diabetes fell by 9% for each 10 g/day increase in total fiber intake, and by 25% for each 10 g/day increase in cereal fiber intake. They did not find a statistically significant relationship between increasing either fruit or vegetable fiber and reducing diabetes risk.

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Published on 1 Comment on Obesity Markers Found In Urine

You can deceive yourself by calling yourself "big-boned" or "hefty", but your urine doesn't lie! Researchers found 29 biological markers in urine that are associated with body mass. These biological markers in urine are a "metabolic signature" of obesity. Note: Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. From Medical Xpress:

Urine profiles provide clues to how obesity causes disease

Scientists have identified chemical markers in urine associated with body mass, providing insights into how obesity causes disease. Being overweight or obese is associated with higher risk of heart disease, stroke, diabetes and cancer, but the mechanisms connecting body fat and disease are not well understood.

The new study, led by Imperial College London, shows that obesity has a 'metabolic signature' detectable in urine samples, pointing to processes that could be targeted to mitigate its effects on health. 

Urine contains a variety of chemicals known as metabolites, from a vast range of biochemical processes in the body. Technologies that analyse the metabolic makeup of a sample can therefore offer huge amounts of information that reflects both a person's genetic makeup and lifestyle factors.

The Imperial researchers analysed urine samples from over 2,000 volunteers in the US and the UK. They found 29 different metabolic products whose levels correlated with the person's body mass index, and how they fit together in a complex network that links many different parts of the body.

Some of these metabolites are produced by bacteria that live in the gut, highlighting the potentially important role these organisms play in obesity. Altered patterns of energy-related metabolites produced in the muscles were also identified as being linked to obesity.

Published on

According to a recent large Swedish study, a healthy lifestyle lowers the risk of ischemic stroke (caused by a blood clot) - up to 54% lower risk. But unfortunately it does not lower the risk for a hemorrhagic stroke.

A healthy lifestyle was considered to be: healthy diet, moderate alcohol consumption, not smoking, being physically active, and being a normal weight (not overweight or obese). The more healthy life-style factors, the lower the risk for an ischemic stroke. In this study, healthy foods were considered to be: fruits, vegetables, legumes (beans), nuts, low-fat dairy foods, whole grain foods, and fish. 

From Science Daily: Healthy lifestyle may cut stroke risk in half for women

Women with a healthy diet and lifestyle may be less likely to have a stroke by more than half, according to a study. The study looked at five factors that make up a healthy lifestyle: healthy diet; moderate alcohol consumption; never smoking; physically active; and healthy body mass index (BMI). Compared with women with none of the five healthy factors, women with all five factors had a 54-percent lower risk of stroke.

For the study, 31,696 Swedish women with an average age of about 60 completed a 350-item questionnaire about their diet and lifestyle. They were then followed for an average of 10 years. A healthy diet was defined as within the top 50 percent of a recommended food score measuring how often the participants ate healthy foods such as fruits, vegetables and low-fat dairy products. Moderate alcohol consumption was defined as three to nine drinks per week. Physically active was defined as walking or biking at least 40 minutes a day along with more vigorous exercise at least one hour per week. Healthy BMI was considered below 25.

Most of the women had two or three of the healthy factors. Only 589 women had all five healthy factors, and 1,535 had none. There were 1,554 strokes among study participants. The risk of stroke steadily decreased with each additional healthy lifestyle factor.

Women who had a healthier diet were 13 percent less likely to have a type of stroke called a cerebral infarction than those whose diet was not as healthy. Women with healthier diets had a rate of 28 strokes per 10,000 women per year compared to 43 strokes per 10,000 women per year among those with a less healthy diet.

Cerebral infarction is the most common cause of stroke, accounting for up to 80 to 85 percent of all strokes. Cerebral infarction is caused by a blockage in a blood vessel preventing blood and oxygen from getting to an area of the brain.

There was no relationship between the healthy factors and the risk of hemorrhagic stroke. Hemorrhagic stroke, which is caused by bleeding in and around the brain, accounts for about 15 to 20 percent of all strokes.

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Here it is, a list of 17 cancers linked to being overweight or obese. From Science Daily:

Overweight and obesity linked to 10 common cancers, over 12,000 cases every year in UK

A higher body mass index (BMI) increases the risk of developing 10 of the most common cancers, the largest study of its kind on BMI and cancer, involving more than 5 million adults in the UK, shows. Each 5 kg/m² increase in BMI was clearly linked with higher risk of cancers of the uterus (62% increase), gallbladder (31%), kidney (25%), cervix (10%), thyroid (9%), and leukemia (9%). Higher BMI also increased the overall risk of liver, colon, ovarian, and breast cancers.

Using data from general practitioner records in the UK's Clinical Practice Research Datalink (CPRD), the researchers identified 5·24 million individuals aged 16 and older who were cancer-free and had been followed for an average of 7·5 years. The risk of developing 22 of the most common cancers, which represent 90% of the cancers diagnosed in the UK, was measured according to BMI after adjusting for individual factors such as age, sex, smoking status, and socioeconomic status. A total of 166 955 people developed one of the 22 cancers studied over the follow-up period. BMI was associated with 17 out of the 22 specific types of cancer examined.

Each 5 kg/m² increase in BMI was clearly linked with higher risk of cancers of the uterus (62% increase), gallbladder (31%), kidney (25%), cervix (10%), thyroid (9%), and leukemia (9%). Higher BMI also increased the overall risk of liver (19% increase), colon (10%), ovarian (9%), and breast cancers (5%), but the effects on these cancers varied by underlying BMI and by individual-level factors such as sex and menopausal status. Even within normal BMI ranges, higher BMI was associated with increased risk of some cancers.

There was some evidence that those with high BMI were at a slightly reduced risk of prostate cancer and premenopausal breast cancer. Based on the results, the researchers estimate that excess weight could account for 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers in the UK.