Published by
Stanford Medicine

Category

Obesity

Big data, Cardiovascular Medicine, Health and Fitness, Obesity, Research

High BMI and low fitness linked with higher hypertension risk

High BMI and low fitness linked with higher hypertension risk

USMC-120412-M-UY543-003Unfit adolescents who have a high body mass index are more likely to suffer from hypertension when they are older than their peers, according to a new study from researchers at Stanford and Lund University in Sweden.

The paper, the first to discover this connection, was published today in JAMA Internal Medicine.

Lead author Casey Crump, MD, PhD, who recently left Stanford to join the Mount Sinai School of Medicine in New York, and his colleagues tapped a unique data source to uncover the relationship: the Swedish military. In the past in Sweden, all males had to join the military at age 18, and Crump and his team examined fitness and health records from more than 1.5 million military conscripts between 1969 and 1997. Thanks to the Swedish national health-care system, they were also able to obtain follow-up information to see when and if adults were diagnosed with hypertension.

I exchanged emails about the study with Crump, who is vice chair for research in the Department of Family Medicine and Community Health; below is our conversation.

Why did you decide to look at this?

Low physical fitness and obesity are very common, modifiable, and have an enormous public health impact.

What is the primary lesson from this work?

We found that both overweight/obesity and low aerobic fitness at age 18 were linked with higher long-term risk of hypertension in adulthood. Importantly, low aerobic fitness was a strong risk factor for hypertension even among those with normal body mass index (BMI). These findings suggest that interventions to prevent hypertension should begin early in life and include not only weight control but also aerobic fitness, even among persons with normal BMI.

Continue Reading »

Global Health, Nutrition, Obesity, Parenting, Rural Health

Chinese children face obesity risk

Chinese children face obesity risk

69186639_e78742d08a_zWith the parents gone away, the children have time to play — and eat, according to new research that examines the health of the millions of Chinese children left with families when their parents move to urban centers.

Researchers from the University of Manchester in England analyzed the dietary choices of 975 children from 140 rural villages. Led by graduate student Nan Zhang, the team found children living with their grandparents or a single parent ate more fat and less protein than children living with two parents. The research appeared in Public Health Nutrition.

The diets of boys particularly worsened, a finding that has complex implications in a society where males are favored, Zhang said in a news release.

The study did not examine why the childrens’ diets changed, but Zhang has several theories. From the release:

The researchers speculate that mothers moving away from home generally earn less, and that these lower earnings act in combination with grandparents’ poorer dietary knowledge or willingness to spend more on food…

Another factor at work could be that prices of protein-based foods such as eggs and meat have increased faster than many households’ incomes.

The study highlights the need for increased public education on nutrition, she said.

Previously: Building the case for a national hepatitis B treatment program in China, Seeking solutions to childhood anemia in China and  “We should act now”: Stanford expert calls for more targeted anti-obesity policies
Photo by T Chu

Health Policy, Obesity, Public Health, Stanford News

“We should act now”: Stanford expert calls for more targeted anti-obesity policies

"We should act now": Stanford expert calls for more targeted anti-obesity policies

U. S. Department of Agriculture's Food Nutrition Service (FNS) helps educate shoppers about the value of food labeling in December 1975. Photo courtesy National Archives and Records Administration.

Reality TV shows like “The Biggest Loser” are popular in part because the audience can relate to the participants — more than two-thirds of adults and about one-third of children and adolescents are obese or overweight in the U.S. The Surgeon General and the Centers for Disease Control and Prevention have declared obesity to be a national epidemic and a major contributor to leading causes of death, including heart disease, stroke, diabetes and some types of cancer.

Although our country is committed to finding solutions to the increase in obesity, public policies have fallen short, according to Deborah Rhode, JD, a Stanford law professor and legal ethics scholar. In a recent journal article, she wrote:

Many policy responses have proven controversial, and those most often recommended have frequently faced an uphill battle at the federal, state, and local level. At the same time that obesity rates have been rising sharply, many jurisdictions have resisted, or rolled back, strategies such as soda taxes or regulation of advertising directed at children.

In the article, Rhode goes on to evaluate anti-obesity policies, including calorie disclosure requirements, taxes or bans on sugar-sweetened beverages, food stamp modifications, zoning regulations, children’s marketing restrictions, physical activities initiatives, food policies and education. She suggests that a more targeted approach is needed to combat obesity. For instance, Rhode recommends creative zoning regulations that restrict the location of fast-food restaurants near schools while encouraging healthy food retailers in underserved neighborhoods.

In a Stanford news release, Rhode noted that the first lady Michelle Obama’s “Let’s Move!” campaign against childhood obesity applies to politics as well as physical activity. Rhode summarized, “Although we need more evaluation of policy strategies, we know enough about what works to chart a course of reform. We should act now on what we know.”

Jennifer Huber, PhD, is a science writer with extensive technical communications experience as an academic research scientist, freelance science journalist, and writing instructor.

Previously: Finding the sweet spot in public health law to regulate sugary drinksStudy shows banning soda purchase using food stamps would reduce obesity and type-2 diabetesCapturing the metabolic signature of obesity and How to combat childhood obesity? Try everything
Photo by U.S. Department of Agriculture

Obesity, Pregnancy, Research, Stanford News, Women's Health

Maternal obesity increases risk for stillbirth, new Stanford study finds

Maternal obesity increases risk for stillbirth, new Stanford study finds

bassinetWomen who are obese when they become pregnant are more likely than other expectant mothers to have a stillborn baby. But most studies of this relationship have included too few people to give detailed information about which obese women are at greatest risk, or which stages of pregnancy are most likely to be affected.

New Stanford research, led by Suzan Carmichael, PhD, and published online this week in PLOS ONE, changes that. The study used a very large California database of vital records on live births and stillbirths, allowing Carmichael’s team to compare 4,000 stillbirths – in which the baby was born dead after at least 20 weeks of pregnancy – to a control group of 1.1 million live births that followed full-term pregnancies.

With the large data set, the researchers were able to examine the effect of mothers’ race and ethnicity, whether the mothers had previously given birth, and how far along the pregnancies were at the time of the stillbirths. They excluded from analysis the cases in which an obvious fetal factor (such as a chromosomal abnormality) or a known maternal disease (such as diabetes) was probably responsible for the stillbirth.

What emerged is a complicated picture. Overall, greater obesity was linked with greater risk of stillbirth, with a 10-unit increase in body mass index equivalent to a 1.5- to twofold increase in stillbirth risk, a finding echoed by other recent research.

But the increase in risk wasn’t equal across all groups of women, or all stages of pregnancy. For instance, among Hispanic women who had never had a child before, the most extreme level of obesity conferred a five- to sixfold increase in the risk of having a stillbirth between 20 and 23 weeks of pregnancy and about a twofold increase in the risk of stillbirth near the baby’s due date, but was not linked with any change in the risk of having a stillbirth between 24 and 36 weeks’ gestation.

A few themes did emerge, however. Obesity consistently increased the risk for the very earliest stillbirths (between 20 and 23 weeks), regardless of a mother’s ethnicity or whether she had had other children. This is similar to another recent Stanford finding that obesity increases the risk for the earliest premature live births.

In the paper’s discussion section, the authors write:

Obesity and stillbirth are both complex, and many potential factors may contribute to their association. Stillbirth may stem from a variety of adverse conditions, including placental insufficiency, preterm onset of labor or rupture of membranes, infection and cord abnormalities. Obesity could contribute to any of these problems. In addition, obesity may contribute to lower sensitivity with regard to detection of fetal complications, on the part of monitoring tools or maternal ability to detect changes in fetal movement.

The authors hope their findings will help shed light on what causes stillbirth and how, perhaps, some cases might be prevented.

The research was funded by the March of Dimes Prematurity Research Center at Stanford University and the Stanford Child Health Research Institute.

Previously: Women who have had a stillbirth are more likely to experience long-term depression, study shows, Losing Jules: Breaking the silence around stillbirth and A call to “break the silence” of stillbirth
Photo by sincerely, brenda sue

Chronic Disease, Health and Fitness, In the News, Nutrition, Obesity, Stanford News

A conversation about the diabetes epidemic

A conversation about the diabetes epidemic

On this morning’s KQED’s morning radio show, Forum, several doctors including Stanford’s Bryant Lin, MD, discussed how diabetes is affecting the health of millions of people globally.

A recent study in the Journal of the American Medical Association estimated that about half of all adults have diabetes (diagnosed or undiagnosed) or pre-diabetes. Lin and his fellow panelists talked about how changes in our diet and lifestyle have fueled the number of diabetic cases, as well as how genetics can tip the odds against certain patients. Lin mentioned that Asians have a higher rate of diabetes than whites, for example.

Like Lin, I have a family history of diabetes. (Like Lin, I’ve also struggled to maintain my weight). That history has made me keenly interested in staying abreast of recent findings about diabetes – and I surprised to hear that among young people, high rates of liquor consumption is influencing diabetes rates. It’s not just soda intake that we have to watch out for.

Another surprising finding that Lin described was that for pre-diabetics, taking Metformin, a drug that helps control diabetes and blood sugar, can help stave off full-blown diabetes. Eventually, it may become routine to prescribe this medication in certain populations, but Lin said that guidelines haven’t caught up with this aspect of diabetes care.

Other factors at play, Lin noted, include the role of the microbiome in promoting or protecting people from diabetes. And people who undergo bariatric surgery for weight management often find their diabetes is cured, but doctors don’t understand exactly why that’s the case.

Despite the staggering number of people affected, it’s clear that we still don’t understand all the complex factors that influence this disease.

Previously: Faulty fat cells may help explain how Type 2 diabetes beginsThe role of nutrition in diabetes prevention and managementThe importance of regular exercise in delaying and treating diabetes and Examining the role of exercise in managing and preventing diabetes

Health and Fitness, Obesity, Pediatrics, Public Health

Taking breaks for physical activity may benefit children’s long-term health

Taking breaks for physical activity may benefit children’s long-term health

109320999_8b61257d14_zHere’s an eye-opening statistic: Children in the United States spend on average 6 hours per day sitting or reclining. As we head into the fall and winter months, it’s likely that the shorter, darker days and chilly weather will only add to our kids being more sedentary.

National exercise standards advocate for children getting at least 30 minutes of exercise daily to curb the risk of obesity, diabetes and other conditions. But for those days when achieving this goal isn’t possible, new research shows that short activity breaks can help offset a lack of exercise.

In the study (subscription required), researchers invited 28 healthy, normal-weight children to visit the National Institutes of Health on two separate occasions. During the first visit, participants were randomly assigned to two groups. One group watched TV, read or engaged in other sedentary activities for three hours; the other group alternated sitting with three minutes of moderate-intensity walking on a treadmill every 30 minutes for the three-hour period. On the return visit, the children switched groups. Each one took an oral glucose tolerance test at both visits. According to an NIH release:

On the days they walked, the children had blood glucose levels that were, on average, 7 percent lower than on the day they spent all 3 hours sitting. Their insulin levels were 32 percent lower.   Similarly, blood levels of free fatty acids — high levels of which are linked to type 2 diabetes — were also lower, as were levels of C-peptide, an indicator of how hard the pancreas is working to control blood sugar.

After the sessions, the children were allowed to choose their lunch from food items on a buffet table. Based on the nutrient content of each item, the researchers were able to calculate the calorie and nutrient content of what each child ate. The short, moderate-intensity walking sessions did not appear to stimulate the children to eat more than they ordinarily would, as the children consumed roughly the same amounts and kinds of foods after each of the sessions.

The study authors concluded that, if larger studies confirm their findings, interrupting periods of prolonged sitting with regular intervals of moderate-intensity walking might be an effective strategy for reducing children’s risk of diabetes and heart disease.

While regular walking breaks may not excite the average child, three-minute dance parties or stomping on bubbles are other options for getting kids out of their seat and moving.

Previously: Pediatrics group issues new recommendations for building strong bones in kids, Understanding the impact of sedentary behavior on children’s health and British government urging toddlers to ‘get physical’
Photo by Miika Silfverberg

Nutrition, Obesity, Research

A call to focus on the nutritional value of foods, rather than calorie counts

A call to focus on the nutritional value of foods, rather than calorie counts

10331709463_60f2188a69_zTo reduce obesity rates, cardiovascular risk and chronic diseases, ditch calorie counting and instead emphasize the nutritional content of foods. That’s the message from a group of British researchers in an editorial recently published in Open Heart.

Drawing on past scientific evidence, the authors argue that physicians, patients and society’s focus on low-calorie foods and diets has resulted in a sacrifice of good nutrition and failed to improve overall public health. According to a press release:

Daily consumption of a sugary drink (150 calories) is associated with a significantly increased risk of type 2 diabetes whereas daily consumption of a handful of nuts (30 g of walnuts, 15 g of almonds and 15 g hazelnuts) or four tablespoons of extra virgin olive oil (around 500 calories) is associated with a significantly reduced risk of heart attack and stroke.

It has been estimated that increasing nut consumption by two servings a week could stave off 90,000 deaths from cardiovascular disease in the US alone.

And the Action for Health in Diabetes trial shows that a low calorie diet on top of increased physical activity in patients with type 2 diabetes was not associated with a reduced risk of cardiovascular death despite significant weight loss and a monitoring period of 13.5 years, [the authors] point out.

“It is time to stop counting calories, and time to instead promote good nutrition and dietary changes that can rapidly and substantially reduce cardiovascular mortality. The evidence indeed supports the mantra that ‘food can be the most powerful form of medicine or the slowest form of poison’,” they write.

Previously: The trouble with the current calorie-counting system, Homemade: Community-based project teaches how to cook for health and Cooked food, calorie counts and food labels
Photo by Mariya Chorna

Ask Stanford Med, Health and Fitness, Nutrition, Obesity, Precision health, Stanford News

A Stanford physician takes a precision health approach to living a healthier lifestyle

A Stanford physician takes a precision health approach to living a healthier lifestyle

timthumbNearly 70 percent of Americans ages 20 or older are overweight or obese, including Larry Chu, MD, a Stanford anesthesiologist and executive director of Medicine X.

Chu, who has struggled with his weight for over a decade, knew he was overweight but didn’t think it was a serious threat to his health. This changed during a routine doctor’s visit. As he explains in a podcast, Chu was shocked to learn that lab results showed he was at high risk for stroke and heart attack. He decided to take action and launch precision:me, a personal blog project chronicling the first 90 days of his journey to live a healthier lifestyle.

Why most of us try to slim down by shunning carbs, stepping up our exercise routines and secretly weighing ourselves each morning, Chu is tracking his health data using a range of gadgets and other tools and sharing the every detail of his progress publicly on his blog. He is also posting photos and podcasts.

Below Chu discusses why he choose to take this unique approach to achieve his weight-loss goals, how he hopes it will inform the broader conversation about obesity and its potential to demonstrate the value of digital tools in enhancing personal health.

What was the catalyst for precision:me?

One of the misconceptions about obesity is that it is a lifestyle disease and if people would only eat less and move more they would be fit. In my case, this is a health journey I have been struggling with since my residency training at Stanford. Using precision health tools to address obesity is a new approach that we are focusing on in precision:me. Stanford has recently announced exciting plans for precision health. I thought it was a good time to share how we at Medicine X see precision health as a novel approach that individuals and their providers can use today to tailor precise and individualized care. It is a very practical and personal dive into developing and implementing a precise plan to modify my diet and metabolic profile to forestall the development of more significant chronic diseases, such as diabetes and heart disease, using data and analytics provided through digital health tools and expert medical, nutritional and fitness collaborators.

Why did you decide to make all of your health data available online for public consumption?

It was an easy and difficult decision at the same time. There is incredible stigma associated with obesity, which we discuss on the precision:me website. Being overweight or obese is a subject that many of us find difficult to talk about. Sharing information can make it easier to start a dialogue. Advances in precision health at Stanford and around the world will depend upon patients sharing their personal health data in a secure and protected fashion with researchers. By sharing my data with the public, I hope to help everyone see what it is like to live with obesity as a condition, break down misconceptions and misperceptions about the disease, and help shine a light on the value of sharing data to help others.

Continue Reading »

Health and Fitness, Nutrition, Obesity, Research

Can food mentions in newspapers predict national obesity rates?

Can food mentions in newspapers predict national obesity rates?

New_York_TimesFood words trending in today’s newspapers could help predict a country’s obesity rates in three years, according to findings recently published in the journal BMC Public Health. 

In the study, researchers examined whether media mentions of food predate obesity prevalence by analyzing mentions of foods in New York Times and London Times articles over the past 50 years. Using this data, they statistically correlated it with each country’s annual Body Mass Index, or BMI. Brennan Davis, PhD, lead author of the study and an associate professor of marketing at California Polytechnic State University, said in a release that results showed:

The more sweet snacks are mentioned and the fewer fruits and vegetables that are mentioned in your newspaper, the fatter your country’s population is going to be in 3 years, according to trends we found from the past fifty years … But the less often they’re mentioned and the more vegetables are mentioned, the skinnier the public will be.

Researchers say the research could help public health officials better understand the effectiveness of current obesity interventions.

Previously: Adventurous eaters more likely to be healthy, new study shows, Want kids to eat their veggies? Researchers suggest labeling foods with snazzy names, Can edible “stop signs” revive portion control and curb overeating? and Can dish color influence how much you eat?
Photo by Jaysin Trevino

Behavioral Science, Health and Fitness, Obesity, Public Health, Sleep

How insufficient sleep can lead to weight gain

How insufficient sleep can lead to weight gain

SnackNap

I don’t think I’ve ever met a person who hates sleep and can’t wait to get less of it. Yet, even though most people want more sleep and know it’s important for their health, few people get as much shut-eye as they need. If you’re one of the many who needs a bit more motivation to get to bed earlier, a recent BeWell@Stanford article on how sleep can affect your weight may do the trick.

In the Q&A, sleep expert Emmanuel Mignot, MD, PhD, director of the Stanford Center for Sleep Sciences and Medicine, explains why and how insufficient sleep can increase your risk of weight gain:

It is very clear that if you’re not sleeping enough, you’re putting yourself at risk for increasing your weight.  If you sleep less than six hours a night, you’re likely to have a higher BMI (body mass index). Longitudinal data — and the evidence is quite strong — shows that if you sleep more over time, you’ll lower your BMI, which correlates with weight reduction.

In the first centuries of human life on earth, if humans weren’t sleeping they were probably looking for food or fleeing a predator. Not sleeping enough was a sign that we were in danger or that we were under stress. When we are sleep deprived, we feel hungry. Data indicates that if you sleep less, you eat more, and it disrupts your hormones. This problem is magnified in today’s world because food is too available!

Mignot also discusses the top reasons why people sleep so little, the importance of naps, and how being sleep-deprived skews our perception of doing and performing well. “[W]e have to make sure we don’t burn the candle at both ends, Mignot said. “Sleeping brings creativity, productivity and the ability to perform at a higher level.”

The piece is a quick, and informative, read.

Previously: Exploring the history and study of sleep with Stanford’s William Dement“Father of Sleep Medicine” talks with CNN about what happens when we don’t sleep wellStanford doc gives teens a crash course on the dangers of sleep deprivation, Narcoleptic Chihuahua joins Stanford sleep researcher’s family and More evidence linking sleep deprivation and obesity
Photo by Goodiez

Stanford Medicine Resources: