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By Gina Kolata A national survey released on Friday by KFF, a nonprofit organization focused on health policy, has found that Americans long for safe and effective drugs for weight loss. But the more they learn about new drugs like Wegovy that are transforming obesity treatment, the more their enthusiasm fades. The survey found that 59 percent of people who were trying to lose weight said they were interested in taking a safe and effective drug. But only 23 percent remained interested when asked if they would take such a drug if it had to be injected. And just 16 percent were still interested if their insurance would not pay for the drug. The list price of the drugs is about $1,300 a month. When they heard they would regain their lost weight it they stopped taking the drug, interest declined to 14 percent. “People always want that magic pill,” said Ashley Kirzinger, director of survey methodology at KFF. “There is no magic.” The survey was conducted in July online and by telephone with a representative sample of 1,327 U.S. adults. That’s the median weight loss experienced by people who take Wegovy, a drug from Novo Nordisk. The new drugs are the first truly effective obesity medicines. They act by stemming people’s appetites and cravings for food. Many patients started by taking Ozempic, a diabetes drug also by Novo Nordisk that led to weight loss as a side effect. But many more patients are asking for Wegovy, which is approved for obesity. Mounjaro, made by Eli Lilly and approved for treating diabetes, is expected to be approved soon for obesity. People taking it lose a median of 20 percent of their body weight. Obesity is a chronic disease that can result in diabetes and other conditions like high blood pressure, heart disease, sleep apnea and joint problems. But it was so difficult to treat obesity that many doctors and patients had all but given up. © 2023 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28865 - Posted: 08.05.2023

McKenzie Prillaman It’s rare to find a product so successful that its makers stop advertising it. But that’s what happened to the weight-loss drug Wegovy in May. In the United States, where prescription drugs can be advertised, developer Novo Nordisk pulled its television adverts because it couldn’t keep up with demand. The injectable medication, called semaglutide, works by imitating a hormone that curbs appetite and was approved as an obesity treatment by the US Food and Drug Administration (FDA) in 2021. In a study, participants who took semaglutide for over a year lost more than twice as much body weight on average — almost 16% — as did people taking an older weight-loss drug that mimics the same hormone1. Semaglutide’s approval for treatment of weight loss came four years after the drug was approved for type 2 diabetes under the trade name Ozempic, also made by Novo Nordisk, based in Bagsværd, Denmark. Demand for Ozempic has skyrocketed as physicians prescribe it for weight loss outside its approved use. Now, even more-potent medications for obesity are on the way. The drug tirzepatide, which is FDA-approved for type 2 diabetes under the name Mounjaro and made by Eli Lilly in Indianapolis, Indiana, imitates two hunger-related hormones. And the company’s drug retatrutide, which mimics three hormones, showed promising results for weight loss in its mid-stage clinical trial, announced at a conference in June. Neither of these newcomers has been approved for obesity. But treating the condition is more urgent than ever. Obesity rates have tripled in the past 50 years, and carrying significant extra weight often brings a heightened risk of other health complications, including type 2 diabetes, heart disease and some cancers. It can also impede quality of life in other ways, such as limiting a person’s range of movement or resulting in feelings of shame because of weight stigma. With this wave of drugs comes a fresh set of questions for researchers. “We are currently in such a dynamic phase of these transformative developments,” says physician-scientist Matthias Tschöp, chief executive of Helmholtz Munich, a research centre in Germany. “We’re still overwhelmed with curiosity.” © 2023 Springer Nature Limited

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28862 - Posted: 08.02.2023

Will Stone Intermittent fasting has taken off in popularity in recent years as an alternative to more traditional weight loss advice, including counting calories, which can be cumbersome and hard to sustain for some people. Intermittent fasting can take different forms. One approach — called time-restricted eating — limits when people eat to a specific window of time, often around six to eight hours. Some research suggests this can be successful for weight loss in the short term because people end up eating less, but it has been less clear how well it works over a longer stretch of time. A study published Monday may have an answer. "We really wanted to see if people can lose weight with this over a year. Can they maintain the weight loss?" says Krista Varady, a professor of nutrition at the University of Illinois Chicago, who has studied intermittent fasting for the past two decades and led the new study. Varady's research finds that intermittent fasting can indeed help people lose weight and keep it off over the course of a year, with effects similar to tracking calories. The results of the clinical trial were published in the Annals of Internal Medicine. Sponsor Message The amount of weight loss wasn't dramatic — equivalent to about 5% of body weight — but the findings are encouraging to researchers in the field, in part because they underscore that people could keep this habit up over a long stretch of time. "That is pretty exciting," says Courtney Peterson, a professor of nutrition at the University of Alabama at Birmingham, who wasn't involved in the research. "This study has the most compelling results suggesting that people can stick with it, that it's not a fad diet in the sense that people can do it for three months and they fall off the wagon for a year." © 2023 npr

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28833 - Posted: 06.28.2023

By Dani Blum Until she started taking the weight loss drug Wegovy, Staci Klemmer’s days revolved around food. When she woke up, she plotted out what she would eat; as soon as she had lunch, she thought about dinner. After leaving work as a high school teacher in Bucks County, Pa., she would often drive to Taco Bell or McDonald’s to quell what she called a “24/7 chatter” in the back of her mind. Even when she was full, she wanted to eat. Almost immediately after Ms. Klemmer’s first dose of medication in February, she was hit with side effects: acid reflux, constipation, queasiness, fatigue. But, she said, it was like a switch flipped in her brain — the “food noise” went silent. “I don’t think about tacos all the time anymore,” Ms. Klemmer, 57, said. “I don’t have cravings anymore. At all. It’s the weirdest thing.” Dr. Andrew Kraftson, a clinical associate professor at Michigan Medicine, said that over his 13 years as an obesity medicine specialist, people he treated would often say they couldn’t stop thinking about food. So when he started prescribing Wegovy and Ozempic, a diabetes medication that contains the same compound, and patients began to use the term food noise, saying it had disappeared, he knew exactly what they meant. As interest has intensified around Ozempic and other injectable diabetes medications like Mounjaro, which works in similar ways, that term has gained traction. Videos related to the subject “food noise explained” have been viewed 1.8 billion times on TikTok. And some of the people who have managed to get their hands on these medications — despite persistent shortages and list prices that can near or surpass a thousand dollars — have shared stories on social media about their experiences. When food noise fades Wendy Gantt, 56, said she first heard the term food noise on TikTok, where she had also learned about Mounjaro. She found a telehealth platform and received a prescription within a few hours. She can remember the first day she started taking it last summer. “It was like a sense of freedom from that loop of, ‘What am I going to eat? I’m never full; there’s not enough. What can I snack on?’” she said. “It’s like someone took an eraser to it.” © 2023 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28830 - Posted: 06.21.2023

By Gina Kolata Eileen Isotalo was always able to lose weight, but always gained it back. Now 66, her first diet was with Weight Watchers at age 14. She went on to try one diet after another and bought so many books on weight loss that she thinks she has more than the public library. In desperation, she finally went to a weight management clinic at the University of Michigan. She had sleep apnea and aching knees, but could not curb her appetite. “It’s just this drive to eat,” said Ms. Isoltalo, a retired interior design coordinator. “It’s almost like this panic feeling when you start craving food.” “My mental shame was profound,” she said. Now, though, since she started taking Wegovy, one of a new class of drugs for obesity that was prescribed by her doctor at the clinic, those cravings are gone. She has lost 50 pounds and jettisoned the dark clothes she wore to hide her body. Her obesity-related medical problems have vanished along with much of the stigma that caused her to retreat from family and friends. But like others at the clinic, she still struggles with the fear others will judge her for receiving injections to treat her obesity rather than finding the willpower to lose weight and keep it off. Yet the drug, she said, “changed my life.” Wegovy and drugs like it make this “a very exciting time in the field,” said Dr. Susan Yanovski, co-director of the office of obesity research at the National Institute of Diabetes and Digestive and Kidney Diseases. About 100 million Americans, or 42 percent of the adult population, have obesity, according to the Centers for Disease Control and Prevention. For the first time, people with obesity, who faced a lifetime of medical jeopardy, can escape the ruthless trap of fruitless dieting and see their obesity-related health problems mitigated, along with the weight loss. But there is still the taint. © 2023 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28821 - Posted: 06.14.2023

By Amber Dance Maybe it starts with a low-energy feeling, or maybe you’re getting a little cranky. You might have a headache or difficulty concentrating. Your brain is sending you a message: You’re hungry. Find food. Studies in mice have pinpointed a cluster of cells called AgRP neurons near the underside of the brain that may create this unpleasant hungry, even “hangry,” feeling. They sit near the brain’s blood supply, giving them access to hormones arriving from the stomach and fat tissue that indicate energy levels. When energy is low, they act on a variety of other brain areas to promote feeding. By eavesdropping on AgRP neurons in mice, scientists have begun to untangle how these cells switch on and encourage animals to seek food when they’re low on nutrients, and how they sense food landing in the gut to turn back off. Researchers have also found that the activity of AgRP neurons goes awry in mice with symptoms akin to those of anorexia, and that activating these neurons can help to restore normal eating patterns in those animals. Understanding and manipulating AgRP neurons might lead to new treatments for both anorexia and overeating. “If we could control this hangry feeling, we might be better able to control our diets,” says Amber Alhadeff, a neuroscientist at the Monell Chemical Senses Center in Philadelphia. AgRP neurons appear to be key players in appetite: Deactivating them in adult mice causes the animals to stop eating — they may even die of starvation. Conversely, if researchers activate the neurons, mice hop into their food dishes and gorge themselves. © 2023 Annual Reviews

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28799 - Posted: 05.27.2023

By Leo Sands Just under half of obese adolescents administered the latest in a new generation of recently approved weight-loss drugs were no longer considered to be clinically obese by the end of a 16-month trial, a study found. The findings support a small but growing body of evidence that the drug semaglutide, which goes by the brand names of Ozempic and Wegovy, can be an effective treatment option for chronic weight management for a range of ages. Obesity rates for children and adolescents are now alarmingly high in many countries, with such significant implications for young lives that the World Health Organization considers childhood obesity “one of the most serious public health challenges of the 21st century.” The authors of the new peer-reviewed study, published Wednesday in the journal Obesity, found that semaglutide was “highly effective” in reducing body mass index among teens. The weights of 134 clinically obese adolescents were monitored for 68 weeks, with participants given a 2.4 milligram injection of semaglutide weekly. By the end of the study, 45 percent of the group recorded a drop in BMI to below the clinical threshold for obesity. Just 12 percent of participants in a separate group who received a placebo were no longer considered to be obese at the end of the trial. Both groups also got lifestyle counseling and had a daily goal of 60 minutes of moderate- to high-intensity physical activity.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28784 - Posted: 05.18.2023

By Erin Blakemore Newly published research suggests that the sons of women with polycystic ovary syndrome (PCOS) are up to twice as likely to develop obesity as their peers. The study in Cell Reports Medicine used data from cohort research following 467,275 male infants born in Sweden between July 2006 and December 2015. Of those, 9,828 were born to a mother with PCOS — and 147 of those boys were eventually diagnosed with obesity. About 2 in 100 Swedish boys who were born to mothers with PCOS became obese during childhood, compared with about 1 in 100 for boys whose mothers did not have PCOS. The risk was higher among the sons of women who had PCOS and a body mass index (BMI) greater than 25 and highest among the sons of women who both had PCOS and did not take metformin during pregnancy. Researchers followed up the analysis with an RNA sequencing study that found higher cholesterol in sons of Chilean women with PCOS than controls. In another analysis, researchers fed a group of mice a fatty, sugary diet and exposed them to high levels of dihydrotestosterone, a hormone that mimics that of pregnant women with PCOS. Their sons were born with metabolic problems that persisted into adulthood, even when they ate a healthy diet throughout their lives. “We could see that these male mice had more fat tissue, larger fat cells, and a disordered basal metabolism, despite eating a healthy diet,” says Elisabet Stener-Victorin, a reproductive endocrinology and metabolism investigator at the Karolinska Institute in Sweden and the study’s lead author, in a news release.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 8: Hormones and Sex
Link ID: 28776 - Posted: 05.10.2023

By Tim Vernimmen This story starts in an unusual place for an article about human nutrition: a cramped, humid and hot room somewhere in the Zoology building of the University of Oxford in England, filled with a couple hundred migratory locusts, each in its own plastic box. It was there, in the late 1980s, that entomologists Stephen Simpson and David Raubenheimer began working together on a curious job: rearing these notoriously voracious insects, to try and find out whether they were picky eaters. Every day, Simpson and Raubenheimer would weigh each locust and feed it precise amounts of powdered foods containing varying proportions of proteins and carbohydrates. To their surprise, the young scientists found that whatever food the insects were fed, they ended up eating almost exactly the same amount of protein. In fact, locusts feeding on food that was low in protein ate so much extra in order to reach their protein target that they ended up overweight — not chubby on the outside, since their exoskeleton doesn’t allow for bulges, but chock-full of fat on the inside. Inevitably, this made Simpson and Raubenheimer wonder whether something similar might be causing the documented rise in obesity among humans. Many studies had reported that even as our consumption of fats and carbohydrates increased, our consumption of protein did not. Might it be that, like locusts, we are tricked into overeating, in our case by the irresistible, low-protein, ultraprocessed foods on the shelves of the stores where we do most of our foraging? That’s what Raubenheimer and Simpson, both now at the University of Sydney, argue in their recent book “Eat Like the Animals” and in an overview in the Annual Review of Nutrition. © 2023 Annual Reviews

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 14: Attention and Higher Cognition
Link ID: 28764 - Posted: 05.03.2023

By Darius Tahir & Hannah Norman, KHN Suzette Zuena is her own best advertisement for weight loss. Zuena, the “founder/visionary” of LH Spa & Rejuvenation in Livingston and Madison, New Jersey, has dropped 30 pounds. Her husband has lost 42 pounds. “We go out a lot,” Zuena said of the pair’s social routine. “People saw us basically shrinking.” They would ask how the couple did it. Her response: point people to her spa and a relatively new type of medication — GLP-1 agonists, a class of drug that’s become a weight loss phenomenon. But she’s not just spreading her message in person. She’s also doing it on Instagram. And she’s not alone. A chorus of voices is singing these drugs’ praises. Last summer, investment bank Morgan Stanley found mentions of one of these drugs on TikTok had tripled. People are streaming into doctors’ office to inquire about what they’ve heard are miracle drugs. What these patients have heard, doctors said, is nonstop hype, even misinformation, from social media influencers. “I’ll catch people asking for the skinny pen, the weight loss shot, or Ozempic,” said Priya Jaisinghani, an endocrinologist and clinical assistant professor at New York University’s Grossman School of Medicine. Competition to claim a market that could be worth $100 billion a year for drugmakers alone has triggered a wave of advertising that has provoked the concern of regulators and doctors worldwide. But their tools for curbing the ads that go too far are limited — especially when it comes to social media. Regulatory systems are most interested in pharma’s claims, not necessarily those of doctors or their enthused patients.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28754 - Posted: 04.26.2023

Heidi Ledford Under the right circumstances, even moderately hungry mice prefer to socialize with the opposite sex than to eat, researchers have found1. In research published on 23 February in Cell Metabolism, scientists treated male mice with a technique that mimics the effects of leptin, a hormone that acts on the brain to suppress appetite. Treated mice were more likely to approach female mice than their food bowls — even if the test rodents had been deprived of food for almost an entire day. The findings reveal a surprising role for leptin in social behaviour. They are also a step towards understanding how animals prioritize different behavioural options in response to ongoing needs — an enduring question in neuroscience, says Gina Leinninger, who studies the neural regulation of feeding at Michigan State University in East Lansing. The paper “addresses a huge gap in the field”, she says. “When you no longer need to eat urgently, it should free you up to do other things.” The new work, Leinninger says, illuminates how the brain juggles these various demands. Food versus friends Neuroscientists Anne Petzold and Tatiana Korotkova at the University of Cologne in Germany, and their colleagues, sought to understand how such decision-making is affected by leptin, which activates a subset of cells in the brain and promotes a feeling of fullness. The researchers injected male mice with leptin and saw that it suppressed feeding, as expected — but also promoted interactions with female mice. The team examined neurons in the brain’s ‘hunger center’, the lateral hypothalamus, that are activated by leptin. The authors’ experiments showed that neurons that can sense leptin were activated when mice interacted with members of the opposite sex. Artificially activating those neurons using a technique called optogenetics raised the likelihood that a mouse would approach a member of the opposite sex. Both results suggest that leptin plays a part in promoting social behaviour. © 2023 Springer Nature Limited

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28682 - Posted: 02.25.2023

McKenzie Prillaman The hotel ballroom was packed to near capacity with scientists when Susan Yanovski arrived. Despite being 10 minutes early, she had to manoeuvre her way to one of the few empty seats near the back. The audience at the ObesityWeek conference in San Diego, California, in November 2022, was waiting to hear the results of a hotly anticipated drug trial. The presenters — researchers affiliated with pharmaceutical company Novo Nordisk, based in Bagsværd, Denmark — did not disappoint. They described the details of an investigation of a promising anti-obesity medication in teenagers, a group that is notoriously resistant to such treatment. The results astonished researchers: a weekly injection for almost 16 months, along with some lifestyle changes, reduced body weight by at least 20% in more than one-third of the participants1. Previous studies2,3 had shown that the drug, semaglutide, was just as impressive in adults. The presentation concluded like no other at the conference, says Yanovski, co-director of the Office of Obesity Research at the US National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, Maryland. Sustained applause echoed through the room “like you were at a Broadway show”, she says. This energy has pervaded the field of obesity medicine for the past few years. After decades of work, researchers are finally seeing signs of success: a new generation of anti-obesity medications that drastically diminish weight without the serious side effects that have plagued previous efforts. These drugs are arriving in an era in which obesity is growing exponentially. Worldwide obesity has tripled since 1975; in 2016, about 40% of adults were considered overweight and 13% had obesity, according to the World Health Organization (WHO). With extra weight often comes heightened risk of health conditions such as type 2 diabetes, heart disease and certain cancers. The WHO recommends healthier diets and physical activity to reduce obesity, but medication might help when lifestyle changes aren’t enough. The new drugs mimic hormones known as incretins, which lower blood sugar and curb appetite. Some have already been approved for treating type 2 diabetes, and they are starting to win approval for inducing weight loss. © 2023 Springer Nature Limited

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28621 - Posted: 01.04.2023

By Laurie McGinley and  Lenny Bernstein Rachel Graham has battled excess weight for years, cycling through trendy diets, various drugs, even bariatric surgery. Nothing worked for long. But last summer, she started a new medication, and today is 40 pounds lighter — and still shedding weight. “It used to be that if I saw food, I would want to eat it,” said the 54-year-old Graham, who is 5-foot-7 and 190 pounds. “Now, if I have three or four bites of food, I don’t want to eat more.” The drug she’s taking, Mounjaro by Eli Lilly, is part of a new crop of therapies that experts are hailing as a medical milestone — a long-sought way to transform the treatment of obesity, one of the nation’s most serious health threats. Designed for diabetes but used for obesity at higher doses, the medications induce loss of 15 to 22 percent of body weight on average — more than enough to significantly reduce cardiovascular and other health risks. That makes them far superior to old-style diet pills that delivered smaller benefits along with nasty side effects such as high blood pressure and loose stools. But during the past year, soaring demand for the drugs has ignited a mad scramble, exposing some of the most persistent problems in the nation’s health-care system, including supply shortages, high costs and health-care inequities. Tensions are surging as patients with diabetes and those with weight problems sometimes compete for the same medications, which are self-administered in weekly injections. Some doctors worry that the drugs, which might have to be taken for life, will overshadow the need for lifestyle changes involving diet and exercise.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28606 - Posted: 12.21.2022

ByElizabeth Pennisi Willpower might be key to getting off the couch to exercise, but bacteria may lend a helping hand. Studies in mice reported today in Nature suggest microbes in the gut may be behind differences in the desire to work out. A research team has homed in on specific microbial molecules that stimulate a rodent’s desire to run—and keep running. By revealing exactly how these molecules talk to the brain, this group has set the stage for finding out whether similar signals help keep humans active. The work “establishes just how critical the microbiome is for exercise and goes incredibly deep in providing a new gut-brain [connection],” says Aleksandar Kostic, a microbiologist at Harvard Medical School who is co-founder of FitBiomics, a company developing probiotics to improve fitness. Kostic, who wasn’t involved in the research, and others speculate that exercise-inducing commands from the microbes might one day be packaged into pills people could take. To explore why some people like to exercise and others don’t, University of Pennsylvania microbiologist Christoph Thaiss studied mice bred to have a lot of genetic and behavioral variation. His team found more than a fivefold difference in how far the mice ran on wheels in their cages—some covered more than 30 kilometers in 48 hours, whereas others rarely moved in their wheels. The active and lazy mice didn’t show any significant differences in their genetics or biochemistry. But the researchers did notice one clue: When treated with antibiotics, mice that were normally highly energetic tended to exercise less. Follow-up studies showed the antibiotic treatment affected the brains of the formerly active mice. The activity of certain brain genes declined, along with levels of dopamine, a neurotransmitter that has been linked to “runner’s high”—that sense of wellbeing that comes with prolonged exercise.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28596 - Posted: 12.15.2022

By Allison Gasparini Are you drinking enough water? The question seems like it should have a straightforward answer — a specific amount of water you need to drink daily to combat dehydration.      But the rate and way in which the human body takes in and excretes water is not as universal as you might expect. By studying more than 5,000 people living in 23 countries and ranging in age from 8 days to 96 years, researchers have found that the turnover of water in a person’s body varies widely depending on the individual’s physical and environmental factors. The results, published in the Nov. 24 Science, suggest that the idea that a person should ideally consume eight 8-ounce glasses of water a day is not a one-size-fits-all solution to peak hydration.     Even within the calculations, “individual variabilities could be huge,” says biomedical engineer Kong Chen, director of the metabolic research program at the National Institutes of Health’s Clinical Center. Yosuke Yamada, a physiologist at the National Institute of Biomedical Innovation, Health and Nutrition in Japan, and colleagues used a stable isotope of hydrogen known as deuterium to track the movement of water through people’s bodies. Drinking water accounts for only half of the total water intake by humans, with the rest coming from food. Simply measuring the amount of water that a person drinks in a day is not enough to accurately gauge water turnover or the amount of water used by the body daily. © Society for Science & the Public 2000–2022.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28592 - Posted: 12.13.2022

By Veronique Greenwood Anyone who’s had a shady oyster or a mushroom soup that didn’t sit well remembers the ominous queasiness heralding impending bad times. Bacteria release toxins that start the body’s process of speedily evacuating the contents of the stomach. It’s a protective mechanism of sorts — getting rid of the invaders en masse is probably helpful in the long term, even if it’s unpleasant in the short. But it has remained something of a mystery how the brain gets the alarm signal, then sends another one to tell the stomach to initiate a technicolor yawn. Your next bout of food poisoning isn’t the only reason to understand this particular neural pathway. Figuring out how to counter it could be helpful for people who develop nausea caused by chemotherapy medication and other drugs. As if fighting cancer isn’t painful and scary enough, patients are often so turned off by food that keeping their weight up becomes a major struggle. In a new study, researchers report that both bacteria and chemotherapy drugs appear to trigger the same molecular pathways in the gut. The findings, which were based on experiments with mice and published Tuesday in the journal Cell, showed that a bacterial toxin and a chemo medication both set in motion a cascade of similar neural messages that cause queasiness. Choosing mice for the study was unusual. Mice, it turns out, can’t puke — a little foible that typically makes it difficult to use them to study nausea. Researchers have used cats and dogs in the past, but the biology of mice in general is so much better understood, with much better tools available to scientists to do so. Cao Peng, a professor at Tsinghua University in Beijing, and his colleagues wondered whether mice might still be capable of feeling ill in the way people do after ingesting a chemo drug or a bad salad — or close enough, anyway, that researchers could use the creatures to understand the origins of the sensation. © 2022 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 11: Emotions, Aggression, and Stress
Link ID: 28537 - Posted: 11.02.2022

By Alice Callahan Katherine Flegal wanted to be an archaeologist. But it was the 1960s, and Flegal, an anthropology major at the University of California, Berkeley, couldn’t see a clear path to this profession at a time when nearly all the summer archaeology field schools admitted only men. “The accepted wisdom among female archaeology students was that there was just one sure way for a woman to become an archaeologist: marry one,” Flegal wrote in a career retrospective published in the 2022 Annual Review of Nutrition. And so Flegal set her archaeology aspirations aside and paved her own path, ultimately serving nearly 30 years as an epidemiologist at the National Center for Health Statistics (NCHS), part of the US Centers for Disease Control and Prevention. There, she spent decades crunching numbers to describe the health of the nation’s people, especially as it related to body size, until she retired from the agency in 2016. At the time of her retirement, her work had been cited in 143,000 books and articles. In the 1990s, Flegal and her CDC colleagues published some of the first reports of a national increase in the proportion of people categorized as overweight based on body mass index (BMI), a ratio of weight and height. The upward trend in BMI alarmed public health officials and eventually came to be called the “obesity epidemic.” But when Flegal, along with other senior government scientists, published estimates on how BMI related to mortality — reporting that being overweight was associated with a lower death rate than having a “normal” BMI — she became the subject of intense criticism and attacks. Flegal and her coauthors were not the first to publish this seemingly counterintuitive observation, but they were among the most prominent. Some researchers in the field, particularly from the Harvard School of Public Health, argued that the findings would detract from the public health message that excess body fat was hazardous, and they took issue with some of the study’s methods. Flegal’s group responded with several subsequent publications reporting that the suggested methodological adjustments didn’t change their findings. © 2022 Annual Reviews

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28469 - Posted: 09.10.2022

Short ribs glazed in a sweet sticky sauce and slow-cooked to perfection, potato chips hand-fried and tossed with a generous coating of sour cream, chicken wings battered and double-fried so that they stay crispy for hours. What is it about these, and other, mouth-watering — but incredibly fatty — foods that makes us reach out, and keep coming back for more? How they taste on the tongue is one part of the story, but to really understand what drives “our insatiable appetite for fat,” we have to examine what happens after fat is consumed, says Columbia University’s Charles Zuker, a neuroscientist and molecular geneticist who has been a Howard Hughes Medical Institute (HHMI) Investigator since 1989. Two years ago, Zuker and his team reported how sugar, upon reaching the gut, triggers signals that are sent to the brain, thus fueling cravings for sweet treats. Now, in an article published in Nature on September 7, 2022, they describe a similar gut-to-brain circuit that underlies a preference for fat. “The gut is the source of our great desire for fat and sugar,” says Zuker. The topic in question is an incredibly timely one, given the current global obesity epidemic. An estimated 13 percent of adults worldwide are obese — thrice that in 1975. In the US, that figure is even higher — at a staggering 42 percent. “It’s a very significant and important health problem,” says Zuker. Having a high body-mass index is a risk factor for stroke, diabetes, and several other diseases. “It’s clear that if we want to help make a difference here, we need to understand the biological basis for our strong appetite for fat and sugar,” he says. Doing so will help us design interventions in the future to “suppress this strong drive to consume” and combat obesity.

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 8: Hormones and Sex
Link ID: 28468 - Posted: 09.10.2022

Sascha Pare Homer Simpson may not be the only one with a region of the brain dedicated to doughnuts: researchers have found that images of food appear to trigger a specific set of neurons. Previous research found that similar regions of the brain are highly specialised to identify and remember faces, places, bodies and words. The team, based at the Massachusetts Institute of Technology (MIT), say they stumbled upon the food-sensitive neurons by accident – and they could have evolved due to the evolutionary and cultural importance of food for humans. “Our most novel result is the discovery of a new neural response that has not been reported previously for the ventral visual pathway and that is highly selective for images of food,” the scientists wrote in the journal Current Biology. The researchers examined brain scans of eight participants taken as they viewed 10,000 images. Pictures of food appeared to trigger a population of neurons in the ventral visual cortex, which processes visual information. “We were quite puzzled by this because food is not a visually homogenous category,” said Meenakshi Khosla, one of the lead authors of the study. “Things like apples and corn and pasta all look so unlike each other, yet we found a single population that responds similarly to all these diverse food items.” Cooked meals such as a cheesy slice of pizza provoked a slightly stronger reactions than raw fruit and vegetables, the researchers noted. To test whether this was due to warmer colours in prepared food, they compared participants’ reactions with cool-toned images of food and richly coloured non-food objects. They found food caused a sharper signal. © 2022 Guardian News & Media Limited

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 28452 - Posted: 08.27.2022

By Gina Kolata Maya Cohen’s entree into the world of obesity medicine came as a shock. In despair over her weight, she saw Dr. Caroline Apovian, an obesity specialist at Brigham and Women’s Hospital, who prescribed Saxenda, a recently approved weight-loss drug. Ms. Cohen, who is 55 and lives in Cape Elizabeth, Maine, hastened to get it filled. Then she saw the price her pharmacy was charging: $1,500 a month. Her insurer classified it as a “vanity drug” and would not cover it. “I’m being treated for obesity,” she complained to her insurer, but to no avail. While Ms. Cohen was stunned by her insurer’s denial, Dr. Apovian was not. She says it is an all too common response from insurers when she prescribes weight-loss drugs and the universal response from Medicare drug plans. Obesity specialists despair but hope that with the advent of highly effective drugs, the situation will change. Novo-Nordisk, the maker of the medicine Dr. Apovian prescribed, and patient advocacy groups have been aggressively lobbying insurers to pay for weight-loss drugs. They also have been lobbying Congress to pass a bill that has languished through three administrations that would require Medicare to pay for the drugs. But for now, the status quo has not budged. No one disputes the problem — more than 40 percent of Americans have obesity, and most have tried repeatedly to lose weight and keep it off, only to fail. Many suffer from medical conditions that are linked to obesity, including diabetes, joint and back pain and heart disease, and those conditions often improve with weight loss. © 2022 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 28342 - Posted: 06.01.2022