Tag Archives: studies

Studying autism in girls may help reveal the disorder’s secrets

Think autism and an image of an awkward boy typically emerges, but the way autism strikes girls — or doesn’t — may help reveal some of the developmental disorder’s frustrating secrets.

Autism is at least four times more common in boys, but scientists taking a closer look are finding some gender-based surprises: Many girls with autism have social skills that can mask the condition. And some girls do not show symptoms of autism even when they have the same genetic mutations seen in boys with the condition.

“Autism may not be the same thing in boys and girls,” said Kevin Pelphrey, an autism researcher at George Washington University.

The causes of autism aren’t known. Genetic mutations are thought to play a role, and outside factors including older parents and premature birth also may be factors. But the gender effect is now a hot topic in autism research and one that could lead to new ways of diagnosing and treating a condition that affects at least 1 in 68 U.S. children.

 

WHAT SCIENCE SHOWS

Brain imaging suggests there may be an additional explanation for why many girls with autism have more subtle symptoms than boys, Pelphrey said. Even in girls who clearly have autism, he said, brain regions involved in social behavior that are normally affected are less severely impaired.

Also, recent studies on autism-linked genes have found that girls can have the same kinds of genetic mutations seen in boys with autism, but not show symptoms. They “even need to have twice as many mutations on average to actually manifest with autism,” said Joseph Buxbaum, director of an autism center at Mount Sinai medical school in New York.

He is among researchers trying to identify a “protective factor” that may explain how some girls at genetic risk remain unaffected — perhaps a protein or other biological marker that could be turned into a drug or other therapy to treat or even prevent autism.

That possibility is likely a long way off, but Pelphrey said this line of research has prompted excitement among autism scientists.

 

AUTISM SISTERS PROJECT

Buxbaum is involved in the Autism Sisters Project, which is seeking to enroll hundreds of families with autistic sons but unaffected daughters. The project began last year with the goal of building a big database that scientists can use to look for genetic clues and protective factors. Girls and their families visit the New York lab to give saliva samples for DNA analysis and efforts are underway to expand DNA collection to other sites.

Evee Bak, 15, hopes her samples will eventually benefit her older brother Tommy. The suburban Philadelphia siblings are just a year apart. They play in a garage band — Evee on drums, Tommy on guitar and vocals. He’s a masterful musician, but has trouble reading social cues and doing things that come easy to other teens, like shopping alone or using public transportation.

Her focus is “taking care of Tommy and making sure he’s happy and healthy,” Evee said.

Tommy was diagnosed at age 3, after he stopped using words he’d learned months earlier and showed unusual behavior including repetitively lining up toys instead of playing with them.

“He’s a wonderful person and I don’t think that we’d ever want to change him,” said his mother, Erin Lopes. But they’d welcome anything that could help him function as independently as possible “because I think that’s what he really wants, is to be independent.”

 

MAKING A DIAGNOSIS

Autism is diagnosed by observing behavior, there’s no blood test for it. Some experts say gender-based differences highlight a need to develop different ways to evaluate boys and girls.

Autism screening, recommended for kids starting at 18 months, uses tools based on research in autistic boys, said Rachel Loftin, clinical director of an autism center at Rush University Medical Center in Chicago.

One widely used screening questionnaire for parents includes questions like “Does your child play make-believe, make eye contact, seek praise, show interest in other children?” Girls with autism, especially mild cases, often don’t show obvious problems in those categories _ they’re more likely than affected boys to play pretend with toys rather than lining them up by size or shape. Loftin said they’re also more likely to show concern for another person’s feelings.

Government data show that all forms of autism, mild to severe, are more common in boys and that the average age at diagnosis is 4 years in boys and girls. But Loftin said anecdotal evidence suggests a two-year lag time in diagnosis for girls, especially those with mild cases. And she suspects many cases are missed or misdiagnosed. That means a delay in early intensive behavior therapy that is the main treatment for autism.

Some girls manage to camouflage symptoms until pressures to fit in at school become overwhelming, delaying diagnosis until around age 8 or 9, said Alycia Halladay, chief science officer at the Autism Science Foundation, a nonprofit educational and research-funding group which is paying for the Sisters Project.

The prominent autism advocate, professor and author Temple Grandin wasn’t fully verbal until age 4.ß “It was obvious something was drastically wrong with me,” Grandin said. But she said she learned to adapt, in part because with “1950’s parenting” she was faced with intense encouragement to develop social skills and other talents.

 

PARENTS’ CONCERNS

Allison Klein worried about her daughter, Jillian, for three years before the little girl was finally diagnosed with mild autism. Jillian couldn’t tolerate loud noises, she grew withdrawn around her preschool classmates and she lagged behind academically. She was labeled anxious, not autistic.

“She didn’t meet the stereotypical behaviors of no eye contact, no communication, hand flapping,” Klein said. Teachers and doctors suggested she was just shy and would grow out of it.

A few months ago, just before Jillian turned 6, Loftin confirmed Klein’s concerns.

Even Pelphrey, the autism researcher, had a similar experience. His daughter, Frances, was diagnosed almost four years after her behavior raised concerns. She didn’t walk or talk until she was almost 3 years old. She tried to be “cuddly” and interact with others, but sometimes she did so awkwardly.

“Nobody really wanted to make the call,” Pelphrey said. “Had she been a boy, there would have been much more pressure to look into it.”

 

On the Web

CDC & Autism: http://tinyurl.com/zarznp2

Wisconsin poverty rate remains unchanged

Wisconsin’s poverty rate remained unchanged from 2013 to 2014, despite the addition of almost 60,000 jobs.

University of Wisconsin-Madison researchers studying economic and policy forces affecting poverty said the rate remained unchanged at 10.8 percent in the eighth annual Wisconsin Poverty Report.

They cited low-wage jobs and part-time employment as factors in the unchanged poverty rate. Other factors included Republican initiatives to decrease antipoverty efforts — including food assistance and refundable tax credits and increases in medical expenses and work-related costs.

Four counties had poverty rates higher than the statewide average of 10.8:

• Dane County, 13.5 percent.

• Walworth County, 16.6 percent.

• Kenosha County, 16.7 percent.

• Milwaukee County, 17.3 percent.

Poverty rates in Washington/Ozaukee, Fond du Lac/Calumet, St. Croix/Dunn, Marathon, Sheboygan and Waukesha were lower than the state average.

Timothy Smeeding, an economist at UW-Madison’s La Follette School of Public Affairs, and Katherine Thornton, a programmer analyst at the Institute for Research on Poverty, developed the analysis outlined in the study.

Meanwhile, a new analysis of poverty in the United States from the Food Research and Action Center finds one in six households struggled to put food on the table in 2015.

“The data in this report represent an economic and political failure that is leaving tens of millions of Americans struggling with hunger and this struggle is happening in every community in America,” FRAC president Jim Weill said. “We must redouble our efforts to ensure no American is left behind.”

Food hardship was highest in Mississippi, where 23 percent of households struggled to buy food.

The low, 8.4 percent, was in North Dakota.

Wisconsin’s hardship rate was 12 percent.

FRAC, in its How Hungry is America? report, called for boosting wages and strengthening government programs, including the Supplemental Nutrition Assistance Program and child nutrition campaigns.

Hard times

How is food hardship measured? Gallup, in the Gallup-Healthways Well-Being Index, measures food hardship with the following question: “Have there been times in the past 12 months when you did not have enough money to buy food that you or your family needed?”

On the Web

Go online to www.wisconsingazette.com to find the Wisconsin Center for Investigative Journalism’s special report on poverty’s toll on young brains and work to close the academic achievement gap.

Seas rising faster than any time in past 2,800 years

Sea levels on Earth are rising several times faster than they have in the past 2,800 years and are accelerating because of man-made global warming, according to new studies.

An international team of scientists dug into two dozen locations across the globe to chart gently rising and falling seas over centuries and millennia. Until the 1880s and the world’s industrialization, the fastest seas rose was about 1 to 1.5 inches (3 to 4 centimeters) a century, plus or minus a bit. During that time global sea level really didn’t get much higher or lower than 3 inches above or below the 2,000-year average.

By 2100 that the world’s oceans will rise between 11 to 52 inches, depending on how much heat-trapping gas Earth’s industries and vehicles expel.

But in the 20th century the world’s seas rose 5.5 inches (14 centimeters). Since 1993 the rate has soared to a foot per century (30 centimeters). And two different studies published this week in the journal Proceedings of the National Academy of Sciences, said by 2100 that the world’s oceans will rise between 11 to 52 inches (28 to 131 centimeters), depending on how much heat-trapping gas Earth’s industries and vehicles expel.

“There’s no question that the 20th century is the fastest,” said Rutgers earth and planetary sciences professor Bob Kopp, lead author of the study that looked back at sea levels over the past three millennia. “It’s because of the temperature increase in the 20th century which has been driven by fossil fuel use.”

To figure out past sea levels and rates of rise and fall, scientists engaged in a “geological detective story,” said study co-author Ben Horton, a Rutgers marine scientist. They went around the world looking at salt marshes and other coastal locations and used different clues to figure out what the sea level was at different times. They used single cell organisms that are sensitive to salinity, mangroves, coral, sediments and other clues in cores, Horton said. On top of that they checked their figures by easy markers such as the rise of lead with the start of the industrial age and isotopes only seen in the atomic age.

When Kopp and colleagues charted the sea level rise over the centuries — they went back 3,000 years, but aren’t confident in the most distant 200 years — they saw Earth’s sea level was on a downward trend until the industrial age.

Sea level rise in the 20th century is mostly man-made, the study authors said. A separate, not-yet-published study by Kopp and others found since 1950, about two-thirds of the U.S. nuisance coastal floods in 27 locales have the fingerprints of man-made warming.

And if seas continue to rise, as projected, another 18 inches of sea level rise is going to cause lots of problems and expense, especially with surge during storms, said study co-author Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany.

“There is such a tight relationship between sea level and temperature,” Horton said. “I wish there wasn’t, then we wouldn’t be as worried.”

The link to temperature is basic science, the study’s authors said. Warm water expands. Cold water contracts. The scientists pointed to specific past eras when temperatures and sea rose and fell together.

The Kopp study and a separate one published by another team projected future sea level rise based on various techniques. They came to the same general estimates, despite using different methods, said Anders Levermann, a co-author of the second paper and a researcher at the Potsdam Institute.

If greenhouse gas pollution continues at the current pace, both studies project increases of about 22 to 52 inches (57 to 131 centimeters). If countries fulfill the treaty agreed upon last year in Paris and limit further warming to another 2 degrees Fahrenheit, sea level rise would be in the 11 to 22 inch range (28 to 56 centimeters).

Jonathan Overpeck at the University of Arizona, who wasn’t part of the studies, praised them, saying they show a clear cause and effect between warming and sea level rise.

On the Web

Journal: http://www.pnas.org

No place like home: Larry Sultan’s MAM retrospective

Is a photograph truth? Whose truth? To what degree? 

The lens of late photographer Larry Sultan (1946–2009) frames those questions and more in the numerous series created throughout his career, and in his major retrospective, at the Milwaukee Art Museum, the viewer may be left to muse over those questions long after leaving the show. 

Larry Sultan: Here and Home begins with an early project embarked upon by the artist and his collaborator, Mike Mandel. Called Evidence, it consists of black-and-white photographs drawn from archives of various institutions — some public, some private. Corporations, government agencies and the academic realm are all opened up, yielding pictures that offer few definitive statements about just what is going on or who is involved, but instead leave a lingering sense of subterfuge. 

In various shots, men in suits hang out on top of a grassy hill and animatedly talk, one gesturing with a walkie-talkie. In another a car burns out in flames. Others isolate strange metallic objects and machines. These are hidden areas of the world, the experiments and endeavors that we only know exist through these photos.

Some of Sultan’s photos aren’t as investigative as these. Some are perusals of intimate, unseen moments, often lurking in the idealized world of California suburbs. 

His parents provide subject material for his Pictures from Home series. A patina of middle-class comfort colors these images. His mother and father are shown in the midst of daily life, as they chat at the kitchen table, hang around the patio, read in bed. 

The project stemmed from revisiting old family movies, which Sultan considered to have the quality of quiet, epic narratives. Some of those movie stills are included in the gallery and are like a time capsule of a sort of mid-century optimism, bathed in golden light. Photographs of his parents at glamorous receptions and even a party dressed as pirates offer evidence of a carefree life of enjoyment. Sultan’s mother, usually with impeccably painted fingernails and polished makeup, embodies an attentiveness to personal image. 

Sultan doesn’t draw away the curtain to reveal a rawer underside, but it is as though he captures the process of self-projection, the accouterments of style and a sense of being cultivated by their personalities. 

Things are more transient in other series, such as The Valley. These images are a glimpse into ordinary homes and settings, temporarily populated by performers and crews shooting adult films. 

Here, Sultan’s lens reveals the artifice, the behind-the-scenes of bodies, cameras, cords and onlookers who exist outside of the filming frame. The Valley series originated from images taken near the photographer’s childhood residence and point to multilayered strata of a constructed fantasy. The sets are ordinary, recognizable slices of Americana, against which fantasies of sex and desire are set with the tacit understanding of their own artificiality. 

Sultan’s final series before his death was called Homeland. Here, the liminal spaces of suburbia are explored: tracts of land behind houses where manicured lawns and swimming pools are separated by fences from the wild bramble that marks neighboring territory, or the tall wild grasses that rise undeterred by the lawn mower’s penchant for uniformity. 

Among these scenes are migrant Latino workers, engaged in activities such as boating or carrying dishes of food through wild paths behind houses. The men were found as laborers waiting to be hired for day jobs. In Sultan’s work their personal sense of transience resonates with spaces that lie in between the tidy notions of the American Dream. 

But as Sultan shows in this retrospective exhibition, these ideas are often cloudy, despite the ubiquitous sunshine, and in many ways, consciously constructed. 

ON DISPLAY

Larry Sultan: Here and Home continues through Jan. 24 at the Milwaukee Art Museum, 700 N. Art Museum Dr. Visit mam.org for more details.

RELATED PROGRAMS AND EVENTS 

DIY Larry Sultan Style 

As part of the exhibition Larry Sultan: Here and Home, the Milwaukee Art Museum has put together Here and Home: The MKE Challenge. Over the course of six weeks, interested participants will be given an assignment to make photographs in the spirit of some of Sultan’s themes and ideas. The first assignment, “Fake Evidence,” involves making an image that takes after the ideas in Sultan’s first major series, Evidence. New assignments are offered weekly, and the event is open to novice and experienced photographers alike. For more information, see mam.org/Larry-Sultan/here-and-home-mke-challenge.php.

Gallery Talk 

Tour the Larry Sultan: Here and Home exhibition with a museum staff expert for a additional information on the work of this highly influential photographer. Thirty-minute Express Talks will be held on Nov. 5 at noon and 5:30 p.m. Curator of photography and media arts, Lisa Sutcliffe, will offer a tour at 1:30 on Nov. 24, the first day the new permanent collection galleries will reopen to the public.

UW-Madison researcher changes monkey study that drew outcry

A mental health researcher at the University of Wisconsin-Madison won’t take newborn monkeys away from their mothers as part of an upcoming study.

Dr. Ned Kalin told the Wisconsin State Journal that complaints from animal rights groups weren’t behind the change in the study. Rather, he says other research found anxiety isn’t increased when newborn monkeys are separated from their mothers.

“We’re changing the experiment based on science, not based on pressure that I’ve had,” Kalin said.

More than 383,000 people had signed an online petition asking that the study be canceled. The study plans to put monkeys through stress tests and euthanize them after a year to study their brains.

Hannah West, executive director of Alliance for Animals and the Environment, said the group still opposes the study. But she said she’s happy the newborns won’t be taken from mothers, no matter the reason.

“The part about removing the babies from the mothers really touches the heartstrings,” West said. “But these tests are really invasive, and they’re killing the monkeys at a really young age.”

Kalin said the study is being done to try to better understand anxiety and depression. Such studies could lead to new drugs and treatments, he said.

Another study done by Kalin had used monkeys that were neglected or abused by their mothers and were removed from them. That study found those monkeys were not more anxious than others not removed from their mothers.

“We actually found less anxiety, to our surprise,” Kalin said.

Kalin plans to begin the new study by June. It was approved nearly a year ago by the school’s animal research committee, and it will include 40 rhesus macaque monkeys.

Overby pursues ‘Higher Ground’ of world music

It’s not unusual this time of year for Wisconsin residents to escape the state’s wintry weather for the Caribbean’s sunny climate. Milwaukee native Jonathan Overby is no different, but the ethnomusicologist is traveling with a purpose greater than mere tourism.

Overby is host and executive producer of Wisconsin Public Radio’s Higher Ground, a show broadcast weekly on Saturday nights from 7 p.m. to 11 p.m. from the UW-Madison campus that “celebrates music with African roots, and more.” An average playlist may include artists as diverse as Senegalese pop singer Baba Maal, The Egyptian Orchestra, a cappella vocalists Chanticleer, jazz giant Duke Ellington or bluegrass banjo-picker Bela Fleck, all of whom Overby says have their roots in traditional African rhythms.

Overby left on Feb. 6 for a 10-day cultural research trip to Cuba. While there, he says, he’ll be exploring the music of Santeria, a religion that blends Old World Catholicism with Yoruba, an African religion brought west by slaves from Nigeria, Benin and Togo. 

Overby holds a Ph.D. in administrative leadership in higher education from Madison’s Edgewood College, but he is making the trip as part of his Edgewood postdoctoral studies in sacred world music. It’s one of nine trips he will make over the next three years to countries around the globe, all while expanding the scope of his radio program.

“What’s powerful about Cuban music, which has been heavily influenced by African motifs, is that it has had a major influence on American music, particularly jazz,” Overby says. “Africa went through the middle passage to this part of the world, particularly to Cuba, where they allowed their enslaved citizens to make musical instruments. That didn’t happen in the U.S.”

Ironically, African-influenced Cuban music made it back to Africa in the 1930s and ‘40s, Overby added, resulting in a unique and influential fusion dubbed “Afro-Cuban jazz.” 

The power of diverse music is nothing new for Overby. He grew up on the corner of Second and Burleigh Streets in Milwaukee’s Harambee neighborhood, the son of a white mother and a black father. His father owned the Club Chateau Lounge on what is now Dr. Martin Luther King Jr. Drive, which opened Overby’s eyes to the depths and variations found in African-American music.

“All that music ignited a fire in my soul,” says Overby, who holds an undergraduate degree in voice and choral conducting from San Francisco State University and a master’s degree from Edgewood with an emphasis on African-American sacred music. “I wanted to unpack that music and flesh it out.”

What Overby found is that access to various forms of music, like much of mid-20th century society, was highly segregated by culture and race. That was an issue already in the forefront of Overby’s mind, growing up in Milwaukee, still ranked the second-most racially segregated city in the United States, behind Detroit. 

Music both sacred and secular formed a cultural bridge for Overby, a trained lyric baritone who loved going to church as a child and is a gospel artist and former music director for the Madison Campus Ministry. The power of music to cross between cultures provided a setting that helped him decide where he would land in service to the global community, he says.

“That is the underpinning of why I do the radio show and what the content of the show includes,” Overby says. “I don’t overtly say what music can do in terms of reducing human hated of things that are different. I don’t say, for example, that the Bible and Quran have been marginalized to justify the killing of certain people. And yet these are two amazing documents that, in my view, offer lessons on how to live life and worship a higher being in the process.”

Overby lets the music speak for him. The show’s name, taken from a spiritual that Overby himself wrote that serves as a theme song, speaks to how music functions to better integrate a society of diverse individuals and cultures that too often is driven by unfamiliarity, fear and hatred.

Higher Ground is centered on music with African roots, but examples of musical integration are legion among every musical genre and origin point. A single example: When Czech composer Antonín Dvořák composed his Symphony No. 9, “From the New World,” in 1893, he integrated the spiritual “Goin’ Home” after hearing it performed by African-American singer Harry Burley. 

Rather than segregating their art, many musicians integrate their influences to communicate across cultures. This became the thesis for Higher Ground, which is broadcast throughout Wisconsin and streamed online for listeners as far off as the U.K., Germany, Iran and Morocco. That sense of humanity also drove a lifetime of study and defined a sense of purpose for Overby.

“I believe there is something viable to the idea of playing a role, even marginally, in reducing human hatred,” Overby says. “That’s where I have landed and that’s where I want to spend some time studying, learning and embracing these other traditions.”

As Overby pursues sacred music in his postdoctoral work, he hopes that the ideas and influences found in the show rub off on his listeners.

“If in listening to the show people find it in any way, shape or form transformative in what they have learned, enjoyed and found educational, then that would be an enormous gift to me,” Overby says.

Wisconsin plays key role in music, memory study

Mike Knutson taught himself to play the harmonica as a child, and the 96-year-old sang with his family for most of his life. Even now, as he suffers from dementia, music is an important part of his life thanks to a study looking at the impact of a nationwide music program aimed at helping dementia patients.

The study being led by the University of Wisconsin-Milwaukee is the largest yet on the impact of the Music and Memory program, which is in hundreds of nursing homes across the U.S. and Canada, said program founder Dan Cohen. Similar studies will be conducted in Utah and Ohio.

Researchers are monitoring the responses of 1,500 Alzheimer’s and dementia patients who were given iPods at Wisconsin nursing homes through the program, which was highlighted in a documentary honored at the Sundance Film Festival this year. Their mental state will then be compared to the same number of people in 100 other nursing homes who haven’t received iPods.

Knutson is often sleepy, but he perks up when nurses put headphones on him or when his family sings with him during visits at the Wisconsin Veteran’s Home in Union Grove, south of Milwaukee.

He smiles, taps his feet and gently claps his hands upon hearing big-band music, which is part of his personalized playlist.

“The music really does something to wake him up and help him to be more engaged with what is going on around him,” said his daughter, Barb Knutson, who lives in Madison.

The state and UW-Milwaukee are investing about $300,000 in the program and study, money received through federal funds acquired from nursing home penalties. The program will be expanded to another 150 Wisconsin nursing homes next year.

For the study, nursing homes put together personalized playlists for residents. Researchers then document residents’ interactions, watch sleep patterns, put on wrist monitors that track movement and collect music data.

The study started this summer, and final data should be available by next summer.

“You may see the immediate effects shown on the residents, but we don’t really know if it actually has longer-term effects,” said Jung Kwak, an associate professor of social work at the university.

Researchers hope to determine whether music improves mood and behavior, which residents might benefit and then tailor activities accordingly. They also want to see if music could someday reduce the need for prescription drugs, Kwak and Cohen said.

Cohen, who founded Music and Memory in New York in 2006, said he hopes the Wisconsin study informs the health care system of the program’s benefits and potential cost savings. He said there’s also fear of visiting dementia patients, so he hopes the program will encourage families and friends to visit more often.

“Then (the patients) will feel more alive and won’t feel as isolated in these facilities,” he said.

Sex to burn calories? Authors expose weight myths

Fact or fiction? Sex burns a lot of calories. Snacking or skipping breakfast is bad. School gym classes make a big difference in kids’ weight.

All are myths or at least presumptions that may not be true, say researchers who reviewed the science behind some widely held beliefs about weight and found it lacking.

Their report in the newest issue of New England Journal of Medicine says dogma and fallacies are detracting from real solutions to the nation’s weight problems.

“The evidence is what matters,” and many feel-good ideas repeated by well-meaning health experts just don’t have it, said the lead author, David Allison, a biostatistician at the University of Alabama at Birmingham.

Independent researchers say the authors have some valid points. But many of the report’s authors also have deep financial ties to food, beverage and weight-loss product makers – the disclosures take up half a page of fine print in the journal.

“It raises questions about what the purpose of this paper is” and whether it’s aimed at promoting drugs, meal replacement products and bariatric surgery as solutions, said Marion Nestle, a New York University professor of nutrition and food studies.

“The big issues in weight loss are how you change the food environment in order for people to make healthy choices,” such as limits on soda sizes and marketing junk food to children, she said. Some of the myths they cite are “straw men” issues, she said.

But some are pretty interesting.

Sex, for instance. Not that people do it to try to lose weight, but claims that it burns 100 to 300 calories are common, Allison said. Yet the only study that scientifically measured the energy output found that sex lasted six minutes on average – “disappointing, isn’t it?” – and burned a mere 21 calories, about as much as walking, he said.

That’s for a man. The study was done in 1984 and didn’t measure an experience for a woman.

Among the other myths or assumptions the authors cite, based on their review of the most rigorous studies on each topic:

• Small changes in diet or exercise lead to large, long-term weight changes. Fact: The body adapts to changes, so small steps to cut calories don’t have the same effect over time, studies suggest. At least one outside expert agrees with the authors that the “small changes” concept is based on an “oversimplified” 3,500-calorie rule, that adding or cutting that many calories alters weight by one pound.

• School gym classes have a big impact on kids’ weight. Fact: Classes typically are not long, often or intense enough to make much difference.

• Losing a lot of weight quickly is worse than losing a little slowly over the long term. Fact: Although many dieters regain weight, those who lose a lot to start with often end up at a lower weight than people who drop more modest amounts.

• Snacking leads to weight gain. Fact: No high quality studies support that, the authors say.

• Regularly eating breakfast helps prevent obesity. Fact: Two studies found no effect on weight and one suggested that the effect depended on whether people were used to skipping breakfast or not.

• Setting overly ambitious goals leads to frustration and less weight loss. Fact: Some studies suggest people do better with high goals.

Some things may not have the strongest evidence for preventing obesity but are good for other reasons, such as breastfeeding and eating plenty of fruits and vegetables, the authors write. And exercise helps prevent a host of health problems regardless of whether it helps a person shed weight.

“I agree with most of the points” except the authors’ conclusions that meal replacement products and diet drugs work for battling obesity, said Dr. David Ludwig, a prominent obesity research with Boston Children’s Hospital who has no industry ties. Most weight-loss drugs sold over the last century had to be recalled because of serious side effects, so “there’s much more evidence of failure than success,” he said.