1. Study suggests calorie counts on menus make a difference

    November 5, 2017 by Ashley

    From the University of Technology Sydney press release:

    One the most comprehensive pieces of research into the impact of displaying calories on menus reveals it not only influences consumers to make lower calorie choices but also encourages retailers to provide lower calorie options.

    The research confirms the move that has been made in Australia towards, and supports a push in the United States, for greater disclosure of calorie or kilojoule information on menus at fast-food outlets and restaurant chains.

    The researchers, Dr Natalina Zlatevska from University of Technology Sydney, Dr Nico Neumann from Melbourne Business School, and Professor Chris Dubelaar from Deakin University, collated 186 studies on the effect on consumers of displaying calories on menus, as well as 41 studies on the effect on retailers.

    The results of the meta-analysis, to be published in the international Journal of Retailing, show that displaying calorie information encouraged a reduction of 27 calories (112 kilojoules) per meal for consumers and 15 calories (62 kilojoules) per menu item by food retailers.

    Lead researcher Natalina Zlatevska, from the Marketing Discipline Group at UTS Business School, says while the calorie reduction isn’t much if you only eat out once a year, for those who eat out regularly it can make a real difference.

    The impact was also greater for women, with a 60 calorie (251 kilojoule) reduction per meal, and for those who are overweight, with a reduction of 83 calories (347 kilojoules) per meal.

    “With more and more food dollars spent on meals purchased outside the home, anything we can do to educate consumers, and make them a bit more aware of their choices is a good start,” Zlatevska says.

    Obesity increases the risk of many chronic and lethal diseases including type 2 diabetes and heart disease, and is a leading cause of premature death in the US, UK and Australia.

    Zlatevska says the finding that retailers adjust the choices they offer when required to display calorie information is significant.

    “In the same way that corporate or financial disclosure changes behaviour, here we see the disclosure effect changing the food environment,” she says.

    “We know that retailers are adjusting so there is the possibility of a combined effect. That is where I think bigger change will probably happen. All these incremental changes add up, it is cumulative.”

    In the US providing calorie information on menus has proved controversial, with constant delays and “push back” from food industry groups fearing the cost of implementing the laws.

    First mandated in the 2010 Affordable Care Act, labelling laws are due to be implemented in the US in May 2018, but already there are suggestions they will again be postponed or watered-down.

    In Australia, displaying kilojoule information on menus is mandatory in NSW, SA, ACT and Queensland for food outlets and restaurant chains with more than 20 stores in a state or 50 nationwide, with Victoria to follow suit next year.


  2. Study suggests marketing food as a “meal” rather than “snack” may help prevent overeating

    November 1, 2017 by Ashley

    From the University of Surrey press release:

    Marketing food as a ‘snack’ leads to increased consumption and continued overeating, a new study in the journal Appetite reports.

    In the first ever study of its kind, Professor Jane Ogden and her researchers from the University of Surrey examined the impact of labelling food products as ‘snacks’ or ‘meals’.

    During this innovative investigation, eighty participants were asked to eat a pasta pot which was either labelled as a ‘snack’ or a ‘meal.’ Each pot was presented as a ‘snack’ (eaten standing up from a plastic pot with a plastic fork) or a ‘meal’ (seated at a table from a ceramic plate and metal fork). Once consumed, participants were invited to take part in an additional taste test of different foods (animal biscuits, hula hoops, M&M’s and mini cheddars.)

    Researchers found that those who had eaten pasta labelled as a ‘snack’ ate more at the taste test then when it had been labelled as a ‘meal.’ It was also found that those who ate the ‘snack’ standing up consumed more (50 per cent more total mass, sweet mass and total calories and 100 per cent more M&M’s) than those who had eaten the pasta sitting down at a table. This unique set of results demonstrate that when a food is labelled as a snack rather than a meal consumption is higher, particularly when standing rather than sitting.

    Researchers have attributed this to a combination of factors and believe that when eating a snack we are more easily distracted and may not be conscious of consumption. They also argue that memories for snacks and meals may be encoded differently in our subconscious and that we are unable to recall what we have eaten as a ‘snack.’

    Jane Ogden, Professor in Health Psychology at the University of Surrey, said: “With our lives getting busier increasing numbers of people are eating on the go and consuming foods that are labelled as ‘snacks’ to sustain them. What we have found is that those who are consuming snacks are more likely to over eat as they may not realise or even remember what they have eaten.

    “To overcome this we should call our food a meal and eat it as meal, helping make us more aware of what we are eating so that we don’t overeat later on.”

    Obesity is a growing problem in the United Kingdom with levels reported to have trebled in the last 30 years with 24.9 per cent of people now deemed obese, the highest levels in Europe. It is estimated that £16 billion a year is spent on the direct medical costs of diabetes and conditions related to being overweight or obese.


  3. Study looks at possible links between sleep and hunger

    October 22, 2017 by Ashley

    From the Scripps Research Institute press release:

    A new study from scientists on the Florida campus of The Scripps Research Institute (TSRI) offers important insights into possible links between sleep and hunger — and the benefits of studying the two in tandem. A related paper from the same lab is providing researchers an accessible tool for pursuing further investigations involving multiple fruit fly behaviors.

    While many humans enjoy a daily caffeine fix, scientists have found that caffeine repels Drosophila melanogaster — a species of fruit fly often used as a model for studying human conditions and genetics. Scientists believe that plants produce the caffeine molecule as a defense mechanism to prevent organisms such as fruit flies from eating them. Regardless of the cause of the fly’s aversion, caffeine does seem to negatively impact their sleep, much like it does in humans.

    Caffeine is known to stave off sleep in humans through pharmacological effects on the adenosine receptor. Nonetheless, many studies in mammals have shown genetic differences in responses to caffeine. Interestingly, caffeine apparently can prevent sleep in fruit flies despite the fact that it doesn’t act through their adenosine receptor.

    Erin Keebaugh, Ph.D., a postdoctoral researcher in Associate Professor William Ja’s Laboratory at TSRI, suspected that the systems responsible for caffeine’s impact on fly (and maybe human) sleep patterns are more complex than a single caffeine and receptor interaction.

    In her study, published in the journal Sleep on October 3, 2017, her team gave groups of flies varying levels of dietary caffeine. They then measured how much the flies slept in the following 24 hours while on those diets. They also studied whether varying levels of caffeine impacted the insects’ feeding behavior by measuring how much they ate over the same 24-hour period.

    Interestingly, the team found that sleep loss couldn’t be explained by caffeine intake alone. Instead, they believe that the sleep loss was mediated by changes in the animal’s feeding behavior. “There could still be a pharmacological effect, but there’s definitely dietary inputs to that,” said Keebaugh.

    The study reinforced the idea that the processes of sleep and eating need to be studied together, explained the scientists, especially as a growing number of researchers investigate the relationship between sleep and metabolic disorders. Further studies into this relationship could lead to the development of therapies that treat disorders such as obesity and diabetes.

    A Closer Look at Fly Behavior

    To that end, another member of the Ja Laboratory, Graduate Student Keith Murphy, has developed a new open-source, customizable technique for jointly studying multiple fly behaviors. Many studies designed to understand the interactions between multiple fly behaviors require researchers to measure each behavior separately; for example, one study measures how much the flies eat while a second study measures how much they sleep, and then the data are combined and compared. With Murphy’s device, the Activity Recording CAFE (ARC), researchers could measure both behaviors simultaneously, giving the researchers a cleaner, simpler strategy to investigate previously convoluted questions.

    Using the ARC protocol, as described in a paper recently published in Nature Protocols, anyone with access to a 3D printer can print the chamber and set it up in two hours or less to collect fly data. The chamber is hooked up to a computer that continuously tracks both the amount of food that a fly consumes and its position in the chamber, which can tell a researcher whether or not it’s sleeping.

    Though the protocol is specifically designed for studying sleep and feeding behaviors, Murphy emphasized that the ARC could be customized to study a variety of behaviors in flies. Researchers could program the machine vision program on the computer to apply optogenetic controls tied to certain behaviors, deliver vibrations or cause the fly’s food to move to assess memory, motivation and other behaviors.

    “We’re hoping that this paper creates a community around the tool and people come up with new uses,” said Murphy. “If others get on board, this thing could change what a small lab can do.”

    In addition to Keebaugh, other authors of the study in Sleep were Jin Hong Park, Chenchen Su, Ryuichi Yamada and William Ja of TSRI. The research was supported by the National Institutes of Health (grant R01AG045036).


  4. Study looks at how both nature and nurture may be influencing eating behavior in young children

    October 16, 2017 by Ashley

    From the University of Illinois College of Agricultural, Consumer and Environmental Sciences press release:

    For most preschool-age children, picky eating is just a normal part of growing up. But for others, behaviors such as insisting on only eating their favorite food item — think chicken nuggets at every meal — or refusing to try something new might lead to the risk of being over- or underweight, gastrointestinal distress, or other eating disorders later in childhood.

    Parents and other caregivers often deem children as being “picky eaters” for a variety of reasons, but there is not a hard-fast definition in place for research. Nutrition and family studies researchers at the University of Illinois have collaborated for the last 10 years to understand the characteristics of picky eaters and to identify possible correlations of the behavior.

    In a new study, the researchers wanted to see if chemosensory genes might have a possible relationship to picky eating behavior in young children. They found that certain genes related to taste perception may be behind some of these picky eating habits.

    “For most children, picky eating is a normal part of development,” says Natasha Cole, a doctoral student in the Division of Nutritional Sciences at U of I and lead author of the study. “But for some children, the behavior is more worrisome.” Cole, also part of the Illinois Transdisciplinary Obesity Prevention Program at U of I, hopes the research can help identify the determinants of picky eating behavior in early childhood.

    Leading up to the taste perception genes study, the U of I researchers identified common characteristics of picky eaters, ages 2 to 4 years, and divided these “types” of picky eaters into distinct groups. Further research from the team looked at how parenting styles may affect picky eating behavior and whether children exhibit picky eating behavior both at home and in childcare — homecare or center-based — situations.

    “This has kind of been an evolution of the research, seeing an interaction rather than just seeing the child as on its own, which, when we first started trying to define a picky eater, we were just looking at the child,” explains Soo-Yeun Lee, a professor in the Department of Food Science and Human Nutrition at U of I. “As we were moving into different parts of the research we realized, it’s not just the child, it’s the caregiver and the environment, as well.”

    Now, they are looking at the influence of “nature and nurture” on a child’s picky eating behavior.

    “Natasha is actually taking a deeper look at the child and genetic predisposition,” Lee says. “She is looking at sensory taste genes and also at some of the behavioral genes that have been highlighted in the literature. She has been looking at the whole field of picky eating research, and classifying it based on ‘nature vs. nurture.’ Nature is the genetic disposition and nurture is the environment and the caregivers.”

    The idea, Lee explains, is based on an orchid/dandelion hypothesis. “There are some genes — the behavioral genes — that make the child more prone and more sensitive to being more behaviorally problematic when external influences are present that may not work out their way. That’s the orchid concept. This may be a sensitive child who may not be as resilient with negative feedback or negative mealtime strategies given by parents, versus a dandelion child who is very robust and resistant to whatever, nurture or not, is given to them.

    “There is that fine line, and it’s not just the nurture, the environment, that’s influencing that, but it’s the child’s susceptibility to the environmental cues as well,” she adds.

    For the study, the researchers collected information about breastfeeding history and picky eating behaviors, such as limited food variety, food refusals, and struggles for control, for 153 preschoolers, as reported by their caregivers. Saliva samples were also taken for DNA extraction and genotyping.

    The researchers looked at genetic variation in single nucleotide polymorphisms (SNPs, pronounced “snips”) from five candidate genes related to taste perception. Of the five, they found that two had an association with picky eating behaviors in the preschoolers. One (TAS2R38) was associated with limited dietary variety, and the other (CA6) with struggles for control during mealtime.

    Interestingly, both the TAS2R38 and CA6 genes are possibly related to bitter taste perception. So it is not surprising that the children who are genetically “bitter-sensitive” may be more likely to be picky eaters (i.e. turning down Brussel sprouts or broccoli). Other chemosensory factors, such as odor, color, and texture, may affect eating behaviors as well. Further studies are needed to see how children’s food preferences are affected by the look or smell of their food.

    Along with continuing to look at genetic associations with picky eating, Cole is also interested in understanding how picky eating behaviors start even in children before 2 years of age. Most picky eating research has focused on children over 2 years, but eating habits begin to form before then. She and the research team recently published another study that reviews the research literature on picky eating in children younger than 2 years. The study discusses picky eating associations from an ecological model, starting with the child, and moving out to the child’s environment.

    “By two years, children know how to eat and have pretty set habits,” Cole says. “There is a huge gap in the research when children transition from a milk-based diet to foods that the rest of the family eats.”

    Cole adds that the research involving children under 2 years shows that 22 percent of those children are perceived as picky eaters by their parents or caregivers. Surprisingly, she also found that each additional month of the child’s age was associated with an increase in food-related fussiness. “So a child could go from rarely being a picky eater to being a frequent picky eater in less than a year,” she says.

    Collecting and integrating this comprehensive information from “Cell to Society” is critical to better understand nature-nurture interactions, as many questions in this area remain unsolved, explains Margarita Teran-Garcia, an assistant professor in nutritional sciences, human development and family studies, and the Carle Illinois College of Medicine at the U of I, and co-author of the paper.


  5. Study suggests you are what you think you eat

    September 20, 2017 by Ashley

    From the British Psychological Society (BPS) press release:

    Despite eating the same breakfast, made from the same ingredients, people consumed more calories throughout the day when they believed that one of the breakfasts was less substantial than the other.

    The research, funded by the Rural and Environment Science and Analytical Services at the Rowett Institute, is the key finding of research led by Steven Brown from Sheffield Hallam University which is being presented today at the annual conference of the British Psychological Society’s Division of Health Psychology.

    Previous studies have investigated the link between how filling we expect liquids (e.g. drinks) or semi-solids (e.g. smoothies/soups) to be and people’s subsequent feelings of hunger up to three hours later.

    These initial expectations have also been shown to be an important determinant of how much people eat at a meal provided a short time later. The current research shows that a similar effect can be seen when using solid foods (i.e. an omelette) and that the influence of those expectations is still present after a longer period of time (four hours later and the total day’s calorific intake).

    A total of 26 participants took part. Over two visits, participants believed they were eating either a two or four egg omelette for breakfast. However, both of the omelettes actually contained three eggs.

    When the participants believed that the omelette was smaller they reported themselves to be significantly hungrier after two hours, they consumed significantly more of a pasta lunch and, in total, consumed significantly more calories throughout the day than when the same participants believed that they were eating a larger omelette.

    Steven Brown said, “Previous studies have shown that a person’s expectations can have an impact on their subsequent feelings of hunger and fullness and, to a degree, their later calorie consumption. Our work builds on this with the introduction of solid food and measured people’s subsequent consumption four hours later, a period of time more indicative of the gap between breakfast and lunch.

    “We were also able to measure participants’ consumption throughout the rest of the day and found that total intake was lower when participants believed that they had eaten a larger breakfast.

    “As part of the study, we were able to take blood samples from participants throughout their visits. Having analysed levels of ghrelin, a known hunger hormone, our data also suggest that changes in reported hunger and the differences in later consumption are not due to a differences in participants’ physical response to the food.

    Therefore, memory for prior consumption, as opposed to physiological factors, may be a better target for investigating why expectations for a meal have an effect on subsequent feelings of hunger and calorie intake.”


  6. Eating triggers endorphin release in the brain

    September 12, 2017 by Ashley

    From the University of Turku press release:

    Finnish researchers have revealed how eating stimulates brain’s endogenous opioid system to signal pleasure and satiety.

    The recent results obtained by researchers from Turku PET Centre have revealed that eating leads to widespread opioid release in the brain, likely signalling feelings of satiety and pleasure.

    Eating a delicious pizza led to significant increase of pleasant feelings, whereas consumption of calorie-matched nutritional drink did not. However, both types of meals induced significant release of endogenous opioids in the brain.

    Opioids are associated with pleasure and euphoria. The study revealed that a significant amount of endorphins is released in the entire brain after eating the pizza and, surprisingly, even more are released after the consumption of the tasteless nutritional drink. The magnitude of the opioid release was independent of the pleasure associated with eating. According to the researchers, it is likely that the endogenous opioid system regulates both feelings of pleasure and satiety.

    -The opioid system regulates eating and appetite, and we have previously found that its dysfunctions are a hallmark of morbid obesity. The present results suggest that overeating may continuously overstimulate the opioid system, thus directly contributing to development of obesity. These findings open new opportunities for treating overeating and the development of obesity, says Professor Lauri Nummenmaa from Turku PET Centre.

    – It was a surprise that endorphins are released in the entire brain and that the nutritional drink had a larger impact. This creates a basis for future research and hopefully we will find ways to study and describe the development and predictors of addiction, obesity and eating disorders, says Researcher, M.D., PhD. Jetro Tuulari.

    The study was conducted using positron emission tomography (PET). The participants were injected with a radioactive compound binding to their brain’s opioid receptors. Radioactivity in the brain was measured three times with the PET camera: after a palatable meal (pizza), after a non-palatable meal (liquid meal) and after an overnight fast.

    The research was funded by the Academy of Finland.


  7. How brain circuits govern hunger and cravings

    June 29, 2017 by Ashley

    From the Beth Israel Deaconess Medical Center press release:

    The urge to satisfy hunger is a primal one, but — as any dieter knows — choices about when and what to eat can be influenced by cues in the environment, not just how long it’s been since breakfast. The fact that food-associated visual cues in television commercials and on highway signs can contribute to overeating is well-documented. But how exactly do these external signals trigger cravings and influence behavior?

    By developing a new approach to imaging and manipulating particular groups of neurons in the mouse brain, scientists at Beth Israel Deaconess Medical Center (BIDMC) have identified a pathway by which neurons that drive hunger influence distant neurons involved in the decision of whether or not to react to food-related cues. Their findings could open the door to targeted therapies that dampen food cue-evoked cravings in people with obesity. The research was published online today in the journal Nature.

    “The main question we were asking is: how do evolutionarily ancient hunger-promoting neurons at the base of the brain, in the hypothalamus, influence ‘cognitive’ brain areas to help us find and eat calorie-rich foods in a complex and changing world?” said co-corresponding author Mark Andermann, PhD, an Assistant Professor of Medicine in the Division of Endocrinology, Diabetes and Metabolism at BIDMC and Assistant Professor at Harvard Medical School (HMS).

    “To put it simply, when you’re hungry, the picture of a cheeseburger may be extremely appealing and effective in influencing your behavior,” explained lead author Yoav Livneh, PhD, postdoctoral fellow at BIDMC. “But if your belly is full after eating a big meal, the same cheeseburger picture will be unappealing. We think that the pathway we discovered from hunger-promoting neurons to a region of the brain called the insular cortex plays an important role here.”

    Brain imaging data in humans support the notion that the insular cortex is involved in deciding if a source of food is worth pursuing. In healthy humans, the insular cortex increases its activity in response to food cues during hunger but not following a meal. Studies suggest that this process often goes awry in patients with obesity or other eating disorders that exhibit excessive cravings. Those findings indicate that specific changes in brain activity, including increased sensitivity to food cues, may underlie these disorders — rather than a ‘lack of willpower’.

    In their study, Livneh, Andermann and co-corresponding author Bradford B. Lowell, MD, PhD, Professor of Medicine in the Division of Endocrinology, Diabetes and Metabolism at BIDMC and Professor of Medicine at HMS, and colleagues focused on the insular cortex, using a mouse model. Because the mouse insular cortex is located at the side of the brain in a hard-to-reach place, Andermann, Lowell, Livneh and colleagues pioneered the use of a tiny periscope that allowed them to see neurons in this previously unobservable part of the brain. The tool allowed the researchers to monitor and track individual neurons in awake mice as they responded to food cues in both sated and hungry physiological states.

    Their experiments demonstrated that visual cues associated with food would specifically activate a certain group of neurons in the insular cortex of hungry mice, and that these neurons were necessary for mice to respond behaviorally to food cues. After mice had eaten until they were full, this brain response to food cues in the insular cortex was no longer present. While the mice were still sated, the researchers used genetic techniques to artificially create hunger by ‘turning on’ hunger-promoting neurons in the hypothalamus. These neurons express the gene for Agouti-related protein (AgRP) and were previously shown to restore simple feeding behaviors. By activating these AgRP neurons, Livneh and colleagues caused sated mice to once again react to visual stimuli and seek more food, and it also restored the pattern of food cue visual responses across neurons in insular cortex to that previously seen in hungry mice.

    “These AgRP neurons cause hunger — they are the quintessential hunger neuron,” explained Lowell. “It’s a major advance to learn that we can artificially turn them on and cause full mice to work to get food and to eat as if they hadn’t eaten in a long time. These neurons seem capable of causing a diverse set of behaviors associated with hunger and eating.”

    Based on their research, it may also be possible to dial down the specific pathway from AgRP neurons to the insular cortex and reduce over-attention to food cues in the environment, ideally without impacting deliberate eating at mealtimes. This hypothesis requires further investigation, the researchers stress, but has exciting implications for the treatment of human obesity and other eating disorders.

    With their unprecedented view into the insular cortex, Andermann and Lowell’s team created a road map of the brain circuitry by which hunger-related AgRP neurons ultimately influence insular cortex. Using powerful genetic and optical methods to switch individual cells on and off at will, the team could observe the effects both on downstream neurons and on behavior. The circuitry they revealed includes the amygdala, thought to update the value of food cues, and the paraventricular thalamus, which is also important for motivated behaviors. The researchers suggest the pathway may bias decision-making by increasing the pros and decreasing the cons of seeking out and eating a given food.

    “We’re still trying to understand how this process works,” said Lowell. “Huge questions remain, but they are now addressable thanks to these new imaging methods.”


  8. Dining hall intervention helped college students choose healthier options

    June 22, 2017 by Ashley

    From the Elsevier press release:

    As students transition from high school to college, they enter a critical period for weight gain. Although eating in a buffet-style dining hall offers freedom and flexibility in food choice, many students cite the abundance of food available as a cause for weight gain. As most college students’ diets are low in fruits and vegetables and high in calories, sugar, fat, and sodium, researchers from the University of Toronto and Memorial University of Newfoundland created a cross-sectional study to examine whether messaging encouraging fruit, vegetable, and water intake could influence the habits of university students.

    “Our labeling, focused on beverages and fruits and vegetables, may have been useful to decrease students’ consumption of sugar-sweetened beverages and increase consumption of water, fruits, and vegetables,” said lead author Mary Scourboutakos, PhD, post-doctoral researcher at the University of Toronto.

    The study was conducted in a dining center on the University of Toronto campus that offered a wide variety of entrees and soups, featured a salad and fruit bar, and had sides, desserts, and 19 beverage options available daily. The first part of the intervention encouraged students to choose water as their beverage by using physical activity calorie equivalent (PACE) labeling, which illustrated the minutes of jogging required to burn the calories in the different beverages offered. In the second part of the intervention, posters were hung in strategically selected locations to promote fruit and vegetable consumption. The posters were placed in attention-grabbing places to maximize exposure to the intervention.

    Data were collected in-person on six events before, and six events after the intervention; inventory data were used as a secondary source. Between 368 and 510 students visited the dining hall for each dinner when data were collected, filling 8,570 beverages cups and taking 3,668 and 954 trips to the salad bar and fruit bar, respectively. After the interventions, sugar-sweetened beverage consumption was reduced and fruit and vegetable intake was increased.

    “We found a significant increase in students drinking water before versus after the intervention, with 43% choosing water before and 54% doing so after,” Scourboutakos said. “Likewise, trips to the fruit bar increased by six percent and trips to the salad bar increased by 12%.”

    These results from a university dining hall setting are promising, particularly regarding the PACE labeling. Interventions to promote increased fruit, vegetable, and water consumption should be repeated in different settings to determine if similarly successful results can be attained.


  9. Study suggests eating in front of a mirror makes food more appealing

    June 20, 2017 by Ashley

    From the Nagoya University press release:

    Researchers at Nagoya University reveal that eating in front of a mirror — or even with a picture of yourself eating — makes food more appealing.

    People rate food as tasting better, and eat more of it, when they eat with company than when they eat alone. This so-called “social facilitation of eating” is a well-established phenomenon; however, exactly what it is about company that produces the effect is not clear.

    Now, researchers at Nagoya University have discovered that the same effect can be achieved in individuals eating alone simply by providing a mirror to reflect them while they eat. The study was published in Physiology & Behavior.

    “We wanted to find out what the minimum requirement is for the social facilitation of eating,” lead author Ryuzaburo Nakata says. “Does another person have to actually be physically present, or is information suggesting the presence of others sufficient?” The researchers found that people eating alone reported food as tasting better, and ate more of it, when they could see themselves reflected in a mirror, compared with when they ate in front of a monitor displaying an image of a wall.

    The research team initially worked with a group of older adult volunteers. Approaches to enhance enjoyment of food in people eating without company are particularly relevant for elderly people, because research has shown that many frequently eat alone. However, when the team repeated the experiment with young adult volunteers, they observed the same “social” facilitation of eating when a mirror was present, suggesting that the effect is not limited to older people.

    In a further experiment, when the researchers replaced the mirror with photos of the volunteers eating, they discovered that the volunteers still experienced an increase in the appeal of food and ate more. Thus, perhaps surprisingly, a static image of a person eating seems sufficient to produce the “social” facilitation of eating.

    “Studies have shown that for older adults, enjoying food is associated with quality of life, and frequently eating alone is associated with depression and loss of appetite,” corresponding author Nobuyuki Kawai says. “Our findings therefore suggest a possible approach to improving the appeal of food, and quality of life, for older people who do not have company when they eat — for example, those who have suffered loss or are far away from their loved ones.”


  10. A flip switch for binge-eating?

    June 8, 2017 by Ashley

    From the American Association for the Advancement of Science press release:

    Researchers have identified a subgroup of neurons in the mouse brain that, upon activation, immediately prompt binge-like eating. Furthermore, repeated stimulation of these neurons over time caused the mice to gain weight. The zona incerta (ZI) is a relatively understudied part of the brain.

    Intriguingly, patients receiving deep brain stimulation of the subthalamus, which includes the ZI, for the treatment of movement disorders can exhibit characteristics of binge eating. To explore this phenomenon in greater detail, Xiaobing Zhang and Anthony N. van den Pol optogenetically labelled GABA neurons in the ZIs of mice.

    They found that stimulating ZI GABA neurons with axons extending into the paraventricular thalamus (PVT) prompted immediate binge-like eating, just two to three seconds after stimulation. Within ten minutes of continuous ZI GABA stimulation, mice rapidly consumed 35% of their daily high-fat food store, meant to be eaten over a 24-hour period.

    The researchers also found that ghrelin, a hormone that signals a reduced energy state in the gut, excited ZI GABA neurons. Upon stimulating the subgroup of ZI neurons for five minutes every three hours over a period of two weeks, the mice significantly increased their food intake, and gained weight.

    Yet, once photostimulation was over, the mice showed a significantly reduced food intake compared with that of controls.

    Lastly, the authors found that stimulation of excitatory axons from the parasubthalamic nucleus to PVT or direct stimulation of glutamate neurons in the PVT reduced food intake.