obesity

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Sugar On The Brain Circuit: Mice Seeking Sweets May Hold Key To Compulsive Overeating

You know the feeling: you’re tired, cranky, low or just have a serious, relentless desire for something sweet. Part of your brain cries out, “No, don’t do it, this will end badly.” But another (louder) part wants what it wants and won’t let up until that pint of Cherry Garcia, or red velvet cupcake or Caramel Macchiato is in plain sight. It’s an itch that must be scratched.

Now, brain scientists at MIT say they’ve identified a specific neural circuit in mice that can increase that compulsive overeating of sweets, but doesn’t interfere with normal eating patterns necessary for survival. More specifically, turning on this set of neurons drove mice to seek the reward of a sugary drink even in the face of punishment (a shock to the foot); and compelled them to eat voraciously even when full.  When the researchers shut down this pathway, however, the compulsive sucrose-seeking decreased.

Why does this matter? The new research, published in the journal Cell, may ultimately provide a target for the treatment of compulsive overeating and sugar addiction in humans, without undermining the clearly critical drive of eating to live, the scientists say.

“Imagine if I told you that in the future, we could change the way our neural circuits communicate in a way that I did not want to binge on sweets, but still allowed me to eat healthy foods when I’m hungry?” says Kay Tye, the study’s senior author and an assistant professor in the Department of Brain & Cognitive Sciences at MIT. “Obviously there is a ton of work that needs to be done to make this vision a reality, but our study suggests that it is possible.”

A Binge-Free Future?

As obesity rates have spiked in recent decades, experts say that overeating in general and consuming too much sugar in particular are major threats to human health.

But Tye says “the real underlying problems are the cravings that lead to compulsive eating, and the behavior of compulsive overeating itself.”

To tease out what might be driving that compulsion, Tye looked to a particular set of neurons in the mouse brain.

She and her colleagues showed that when mice perform reward-seeking actions enough that they become habits, that activates neurons connecting two key areas: a brain region called the lateral hypothalamus (an area important for hunger, feeding and homeostasis) and the ventral tegmental area (a brain region important for motivation and reward).

“If we want to understand how the brain gives rise to these feelings, thoughts and actions, we need to know more than what they are saying, we need to know who they are talking to,” Tye said. The team used so-called “optogenetic projection-defined phototagging” [essentially using laser light to activate or silence neurons] to see “which neurons…were saying what…and who they were talking to…”

These neural communications are quite distinct, Tye said; for instance, it’s important to distinguish between two types of reward-seeking behavior: binge-eating and drug addiction: “You don’t need cocaine to survive, you need food to survive,” she said.

The “Wanting” Neurons

Tye says that one of the biggest challenges with treating the obesity that comes from compulsive overeating disorders is that “most treatments are just a band-aid — treating the symptoms instead of the core problems.  Gastric bypass for example, is something that just makes it harder to eat, it doesn’t always change a person’s habits and eventually many people relapse and regain the weight.” Again, she theorizes that it’s the craving embedded in the brain that drives the compulsive behavior. She says there may be a distinctive set of  “wanting neurons” as opposed to “liking neurons.” Continue reading

That Extra Slice: Study Finds When Kids Eat Pizza, They Eat More Calories

Pizza birthday party (Flickr Creative Commons)

Pizza birthday party (Flickr Creative Commons)

By Alvin Tran
Guest contributor

Parents, if you want to prevent your kids from eating too many extra calories, you might want to think twice about letting them have that “just one more” slice of chewy dough, tangy tomato sauce and glistening melted cheese.

In a new study, published Monday in the journal Pediatrics, researchers found that pizza contributed to children and adolescents consuming more calories, saturated fat, and sodium in their usual diet.

“They’re taking in substantially more nutrients we really want to be thinking about limiting,” said Lisa Powell, PhD, a University of Illinois at Chicago professor of health policy and administration and the study’s lead author.

Powell’s study, which analyzed 24-hour dietary recalls of more than 12,000 kids over a 7-year period, found that children between the ages of 2 and 11 consumed an extra 84 calories on the days they ate pizza, while adolescents consumed an extra 230 calories.

It’s not a good idea to eat pizza as a snack.
– Lisa Powell, PhD

They also consumed significantly more sodium and saturated fat, which nutrition and health experts often dub the “bad fat.”

There is a silver lining, however. Children’s overall caloric intake from pizza declined by 25 percent over the course of the study. The study’s adolescent population, which ranged from ages 12 and 19, also demonstrated similar trends: its caloric intake from pizza fell by 22 percent.

But while the number of calories that adolescents consumed dropped, their overall consumption, on average, did not significantly change over the course of the study. According to Powell and her co-authors, this may be due to a slight increase in pizza consumption.

“The average adolescent takes in 620 calories of pizza. By showing that they consume this extra 230 calories, that means that on days they consume pizza, they’re not adequately adjusting the caloric intake and other things they take in that day,” Powell said. “They may be eating pizza but they’re having this additional 230 calories that they’re taking in.”


Overall, pizza consumption remained highly prevalent across both groups. In 2009 to 2010, 20 percent of children and 23 percent of adolescents consumed pizza on a given day.

Powell and her colleagues also found that consuming pizza as a snack or from fast-food restaurants were the two greatest culprits influencing both children and adolescents’ overall daily calorie intake.

“It’s not a good idea to eat pizza as a snack. That’s one thing that teens and parents should keep in mind,” Powell said. Continue reading

Why To Exercise Today (Even A Short Walk): Avoiding A Premature Death

I’ve been having such a hard time dragging myself out in the frigid, icy cold to run or get to a gym lately: there are so many excellent reasons not to do it. But here’s the best I could come up with today for why I shouldn’t listen to that “stay-warm-and-slip-into-bed-with-a-laptop little voice in my head: exercise is truly the “best way to avoid an early death,” according to U.K researchers, who report that even small chunks of exercise — a brisk 20-minute walk, for instance — can provide benefits.

Steve Koukoulas/flickr

Steve Koukoulas/flickr

The U.K. Telegraph headline sums up the new study tidily: “Lack of exercise is twice as deadly as obesity, Cambridge University finds.”

Indeed, this cohort study of 334,161 European men and women over 12 years, published in the American Journal of Clinical Nutrition found that “physical inactivity may theoretically be responsible for twice as many total deaths as high BMI” and concludes: “The greatest reductions in all-cause mortality risk were observed between the inactive and the moderately inactive groups across levels of general and abdominal adiposity, which suggests that efforts to encourage even small increases in activity in inactive individuals may be of public health benefit.”

Here’s more from The Telegraph report:

Using the most recent available public data, the researchers calculated that 337,000 of the 9.2 million deaths that occurred in Europe in 2008 could be attributed to obesity.

But physical inactivity was thought to be responsible for almost double this number – 676,000 deaths. Continue reading

Hey, Guys: Post-Holiday Belly Fat? Better Start Lifting

(Mr.TGT/Flickr via Compfight)

(Mr.TGT/Flickr via Compfight)

If your resolutions included a re-energized commitment to cardio, you might want to reconsider your program.

A recent study by researchers at the Harvard School of Public Health reports that for men over 40, aerobic exercise alone may not be enough to rid you of your ring around the middle.

The study, published in the journal Obesity, found that men who did 20 minutes of daily weight training gained less abdominal fat than men who did 20 minutes of daily aerobic activity. A combination of cardio and weight training led to optimal results. Continue reading

Weight Loss 2015: How To Get A Little Help From Your (New) Friends

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If you made your resolution to lose weight in 2015 on New Year’s Eve, chances are you’re already feeling your initial determination start to flag. The dreary winter dusk calls for comfort food, and there’s slush between you and the gym.

So it’s time for a little help from your friends — only, maybe they should include new friends, not just the usual posse. Not the network that may have influenced you to over-indulge in the first place.

Dr. Sherry Pagoto, an associate professor of medicine at the University of Massachusetts Medical School and an obesity researcher, says studies show that social support is important for making lifestyle changes. “But just because you’ve decided to make a change, that doesn’t mean your friends or family members have. So what do you do? The best support comes from people who are on the same journey.” Social media lets you find people who are “exactly where you’re at, have the same interests and can support each other.”

“Maybe you don’t need everyone in your family to be as dedicated about the gym as you are,” she adds. “But if you can post to your online community — ‘I’m headed to the gym’ or ‘I just got back from the gym’ or ‘I’m on day 5 of my couch-to-5K’ — you’ll have someone who says, ‘Yay!'”

Here, Dr. Pagoto offers five top tips for using social media to help with weight loss:

1. Create a private Facebook group for friends interested in losing weight.

How? It’s easy: Post on Facebook asking if anyone wants to join a private weight loss group. Then create a group page (private, not public) and send invites to those interested. Identify a day when people report weight change from the last week, and a day to post goals for the coming week. Ask people to post helpful content, recipes, their exercise plans, questions, struggles and more throughout the week.

2. Find an existing weight loss community, such as those on Sparkpeople, Weight Watchers or MyFitnessPal websites.

Many are free. Just be sure they are promoting healthy lifestyle change, not a particular specialized diet.

3. Most commercial weight loss apps allow you to ‘friend’ other users. Connect with other serious users to increase your social support and motivation. Continue reading

Confessions Of A Physician Sugar Addict

(Mel B via Compfight)

(Mel B via Compfight)

By Terry L. Schraeder, M.D.
Guest contributor

In medical research, the “n” value is the number of people in a study. If n = 1, it is not generally considered a very powerful study. But when you are the “1” in “n = 1,” it somehow becomes more significant.

It all started with a can of soda disguised as sparkling orange juice. It had become my “go to” treat. My pick-me-up when I was low. In fact, it gave me a rush of energy every time I drank it. One day, I looked at the label to see if it contained caffeine. No caffeine, just added sugar. In fact, it contained 32 grams of sugar — eight teaspoons per can — with sugar second only to water as the largest ingredient. The World Health Organization recommends women not consume more than six teaspoons of added sugar per day — or about 5 percent of total calories as added sugar. Men can have up to nine teaspoons.

How much sugar was I consuming a day? I was also adding honey to my coffee, maple syrup to my oatmeal, consuming corn syrup in my “healthy” flavored yogurt (some brands add as much as 30 grams per serving) and enjoying muffins as a snack and dessert many evenings. Along with my routine stop for a drive-through flavored coffee drink, and occasional cookies or candy, I had officially joined our nation of fellow sugar addicts.

In the US, we are consuming on average 88 grams or 22 teaspoons of added sugar a day. (There are four grams of sugar per teaspoon.) My guess is that I was eating even more. Like many, I needed my fix of high fructose corn syrup or other sugar source every few hours.

For the last several years, there has been an increasing drumbeat of warnings linking sugar to obesity, diabetes, heart disease, cancer and nonalcoholic fatty liver disease from experts such as endocrinologist Dr. Robert H. Lustig at the University of California at San Francisco and media doctor Dr. Sanjay Gupta at CNN. But somehow the message had missed me. I did not think of myself, especially as a physician, as a high sugar consumer.

I have tried to stop the hourly IV drip of added sugar I was consuming throughout the day.

I have passed my 50th birthday and have a normal body weight and exercise regularly. I am not on any medication. My blood pressure and fasting blood glucose are normal. But last year, my triglyceride level was high. One reason might be that the high fructose corn syrup I was consuming is converted to triglycerides in the liver – hence the high level.

There were other concerns. I noticed that I felt shaky and had food cravings two hours after eating. I also noticed an afternoon slump of low energy, a growing bulge of belly fat, and plaque that needed to be vigorously scraped from my teeth every six months. How long had my sugar intake been so high?

Sugar consumption in the US has climbed into the stratosphere in the past three decades. Our added sugar consumption increased by 30 percent from 1977 to 2010, according to a study presented last week at ObesityWeek, a major obesity conference, in Boston. It seems we are slurping, sucking and chewing 300 calories of added sugar daily (up from 228) and far more than the recommended limit of 100 calories of added sugar per day. Continue reading

Studies: It May Be Better For Kids Who Are Overweight Not To Know It

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According to the scale, the 18-year-old girl is severely obese. But she doesn’t think so.

“I know I’m big, but I’m not obese,” she says. “I don’t take up three seats. My weight is high, but no higher than lots of people’s. It’s no problem.”

If you’re her doctor or school nurse or parent, what do you do? Do you bombard her with Body Mass Index charts and warnings of the health risks she faces? Knowledge is power, right? Certainly, that’s the principle behind the “BMI report cards” — colloquially known as “fat letters” — that schools send home in some states.

But research just presented at ObesityWeek, a major conference on obesity, suggests that it may not be wise to persuade that young woman that she has a problem.

One study found that overweight teens who “misperceive” their weight as normal end up gaining less weight over the next decade or so than teens who are overweight and know it. Another study found that those “misperceivers” blind to their extra pounds were also less likely to become depressed in later years.

The findings are at odds with the basic assumption behind BMI report cards, that it is helpful to inform kids and their families of their weight status, says researcher Kendrin Sonneville, an assistant professor at the University of Michigan School of Public Health who is also affiliated with Harvard and the Division of Adolescent/Young Adult Medicine at Boston Children’s Hospital.

Kendrin and IdiaXXX

Dr. Kendrin Sonneville and Dr. Idia Thurston at the Obesity Week conference, where they presented studies that found that weight “report cards” may backfire. (Carey Goldberg/WBUR)

“I think we can say the jury is still out,” she says. “Weight misperception is not something we should assume is harmful, and in the spirit of doing no harm, I think we need to proceed with caution on any type of programming that involves correcting weight misperception.”

The study she led, which followed more than 2700 young people beginning in high school, found that after about a decade, the overweight teens who had perceived their weight accurately gained more than one BMI unit — very roughly about 10 pounds — more than those overweight teens who had falsely believed their weight to be normal.

Why might this be? That’s one of the next avenues of research that need to be explored, but clinical psychologist Idia Thurston, an assistant professor at the University of Memphis, says the key could be the emotional baggage that comes with being told you’re overweight or obese.

More accurate weight perception may translate into more feelings of stigma and lower satisfaction with your own body, she says, “and that could affect your ability to cope — hence, depressive symptoms or hence, engaging in harmful eating behaviors.”

“So when we think about weight report cards and telling kids, ‘This is what your weight status is,’ you really need to think about how that information is being disseminated, and what kinds of protections are put into place, rather than just sending report cards home to kids and not knowing how kids will act on that information.”

Dr. Thurston’s study, also presented at ObesityWeek, found that overweight high-school-aged boys who accurately perceived their own weight as high were significantly more likely to develop depressive symptoms over the next decade or so. (The findings in girls were not statistically significant.) Once again, a false sense of being a normal weight appeared to be protective for overweight young people.

The idea of having schools screen kids for obesity began in 2003 in Arkansas during then-Gov. Mike Huckabee’s anti-obesity efforts, Dr. Sonneville says, and spread around the country without ever having a solid research base on what its effects might actually be.

About one-fourth of states track schoolchildren’s height and weight, and last year U.S. News reported that nine sent weight “report cards” home, including Massachusetts. But last October, facing pushback from nurses, parents and others, the state’s Public Health Council voted to stop sending the letters home, though the schools still gather the information. U.S. News reported that decision under the headline “Massachusetts Schools To Stop Sending ‘Fat Letters:'” Continue reading

Fat Stigma Fading? Fewer See Obesity As Problem Of Bad Personal Choices, Survey Says

Are public perceptions and stereotypes around obesity beginning to shift?

Maybe.

New research presented this week in Boston suggests that the general public and health care providers are starting to view obesity more as a “community problem of shared risks” as opposed to a personal problem stemming from “bad choices.”

These findings were presented as part of The Obesity Society’s Annual Meeting.

Americans’ view on fat has been evolving for some time, spurred by a robust “fat acceptance movement” and a decision last year by the American Medical Association to officially recognize obesity as a disease.  Also, a wave of media and advocacy revolving around healthier eating and lifestyles, from Michelle Obama’s Let’s Move campaign to the film Fed Up, has focused the national attention on the nitty gritty of food and weight.

The Obesity Society

The Obesity Society

The latest research shows that bias against fat people may also be evolving.

Here’s more from the Obesity Society news release:

…For adults in the United States, perception has moved away from seeing obesity as a personal problem resulting from bad choices. Healthcare professionals were already less likely than the public to view obesity as a personal problem of bad choices.

“Despite the high prevalence of obesity in the U.S. and worldwide, weight bias and stigma continue to complicate clinical and policy approaches to obesity treatment,” said study author Ted Kyle, RPh, MBA, of ConscienHealth in Pittsburgh, PA. “The goal of our study was to measure any shifts that might affect or result from public policy changes.” Continue reading

Berkeley ‘Says No To Big Soda,’ First To Pass Tax On Sugary Drinks

sodabottles

In the flurry of election results, don’t miss this milestone with potential public health significance from Caifornia: Berkeley has voted to tax sugary drinks one penny per ounce, and a majority of San Franciscans voted for a similar measure, though it fell short of the two-thirds it needed to pass.

From the Los Angeles Times, which reports that Berkeley is “the first electorate in the nation to approve a tax on sodas and other sugary beverages”:

The [Berkeley] measure was backed by public health advocates and the city’s elected leaders, who said the tax would reduce consumption of sugary drinks and raise awareness of the link between sugary drinks and diabetes and other diseases. The measure’s backers say a national soda tax in Mexico has caused people there to consume fewer sugary drinks.

The American Beverage Association spent $2.4 million to defeat Measure D, and an additional $9.1 million to fight San Francisco’s Proposition E, which would have imposed a 2-cents-an-ounce tax on sodas and other sugar-sweetened drinks.

Though 54.5% of San Francisco voters backed the sugary-drink tax, a tally of 66.67% was needed to pass the measure. The two-thirds threshold was required because the tax revenue would have gone to a special fund for recreation and nutrition programs in schools and parks. The Berkeley measure needed only a majority to pass because that revenue went into the city’s general fund.

“We’re saying no to Big Soda,” Berkeley Mayor Tom Bates said, according to the Associated Press. “We’re saying that Berkeley and the rest of the country need to pay attention that soda is such a destructive product.”

Proposals for a similar tax in Massachusetts have been floated for years now. A few examples:

• In 2009, a group of economists and public health experts, including those from Harvard Medical School and the Harvard School of Public Health, called for a tax on sugar-sweetened beverages to fight obesity and fund health care costs.

• In 2011, Massachusetts pediatricians and other health-promoters concerned about obesity officially launched a concerted campaign against sugary drinks and candy, pushing a bill to remove the sales tax exemption on soda.

• In 2013, Gov. Deval Patrick pushed the idea of removing the tax exemption in the legislature, saying candy and soda should not be considered food and thus exempt from the state’s 6.25 percent sales tax.

Thus far, the Mass. attempts to tax soda have failed. But meanwhile, evidence has been mounting that such efforts have an effect against obesity, and the Berkeley vote translates the data into political impact.

The Center For Science in the Public Interest hailed the vote as “a historic victory for public health,” saying Berkeley has “shown it can be done.”

On the other hand, the Associated Press quotes American Beverage Association spokesman Roger Salazar as unworried that Berkeley is a harbinger of sweeping change. Berkeley “doesn’t look like Anytown USA,” he says.

Readers? Do you think these California votes will have any effect elsewhere?

Study: Aerobics Plus Resistance Training May Be Best Against Teen Obesity

obese kid

A new study published online in JAMA Pediatrics finds that a combination of aerobic workouts plus resistance training offers the best hope for teenagers battling obesity.

From the abstract:

Aerobic, resistance, and combined training reduced total body fat and waist circumference in obese adolescents. In more adherent participants, combined training may cause greater decreases than aerobic or resistance training alone.

Here’s more from The New York Times coverage of the study, which found that “diet without exercise accomplishes little:”

Canadian researchers put 304 obese teenagers on a diet with a daily energy deficit of 250 calories (measured from their resting energy expenditure). Then they assigned them randomly to one of four groups for 22 weeks: aerobic training on exercise machines like treadmills, resistance exercise using weight machines and free weights, combined aerobic and resistance training, and a diet-only group with no exercise… Continue reading