1. Study suggests painting a realistic picture of difficulties of weight loss may actually be helpful

    February 9, 2018 by Ashley

    From the Drexel University press release:

    To reach your New Year’s fitness goals, a bit of reverse psychology might be in order. Telling people that weight loss is extremely challenging — rather than imparting a “You can do it!” mantra — motivated them to shed more weight, according to a new study by psychologists at Drexel University. However, the strategy did not compel participants to achieve the goal for which it was originally designed: to modify or replace many of the unhealthy foods in their homes.

    The study’s findings, published this week in the American Journal of Clinical Nutrition, have conflicting implications, says Michael Lowe, PhD, a professor at Drexel’s College of Arts and Sciences.

    “On one hand, giving overweight people a realistic sense of the dilemma that they are in and the powerful forces they are up against — including a genetic predisposition toward obesity and an increased susceptibility to many food cues in the environment — may actually promote cognitive restraint over their eating in the short-term,” Lowe said. “But, on the other hand, this message did not motivate participants to make numerous changes to the foods they surround themselves with.”

    Lowe and a team of researchers originally set out to determine the effectiveness of three weight loss interventions: behavior therapy, behavior therapy plus meal replacements, or a condition focused on getting people to change foods in their home food environments. They enrolled 262 overweight and obese individuals and assigned them to one of the three methods, while tracking their weight over a three-year period.

    Behavior therapy — the current “gold standard” in weight loss treatment — involves group support, regular weigh-ins, exercise, explicit goal setting and monitoring food intake, while meal replacement treatment replaces breakfast and lunch with calorie-controlled shakes or nutrition bars.

    Behavior therapy is aimed at bolstering someone’s internal sense of self-regulation over food intake and exercise. But research has shown that increases in self-control are not sustainable, and lost weight is almost always regained. The powerful lure of foods high in fat, sugar and salt has been well-documented, and existing treatments do not do enough to ensure that foods kept in the home are permanently changed in ways that make self-control more feasible, according to Lowe.

    “You can’t just give advice,” he said. “You have to work with people to eliminate and substitute very specific foods, and teach them to prepare food differently.”

    That’s why his research team hypothesized that modifying the home food environment (or HFE) would be the most effective strategy for losing and maintaining weight loss. Participants in this group were given homework assignments to identify and make numerous changes to specific foods that were still satisfying but less calorically damaging.

    “Asking people to make healthy decisions, when there are thousands of food choices available, is both emotionally challenging and also complicated,” Lowe said. “HFE treatment is really about mechanically trying to ensure that these changes are made, so the level of chronic temptation generated by foods in their homes is reduced.”

    Most importantly, the research team repeatedly reminded the HFE group about the challenges associated with weight loss and maintenance. In doing this, the researchers aimed to acknowledge the participants’ vulnerability to overconsume favorite foods.

    “We said, ‘It’s impressive and encouraging that you are taking this step to improve your weight and health, but we need to help you understand the daunting challenges you’re facing.’ The reason we did this was not to discourage them, but to give them a more realistic sense of how crucial it is for them to make lasting changes in their parts of the food environment that they could control,” Lowe said.

    People struggling with their weight are likely to hold themselves responsible, even though a number of internal (heredity, for example) and external (fast food restaurants) forces are at play and beyond their control, Lowe said. The researchers suggested that by making multiple changes to their food environment, participants would be reducing the need to perpetually exercise self-control to maintain the weight they lost.

    In addition to measuring the participants’ weights during six assessment sessions over three years, the researchers also assessed conditions such as binge eating, quality of life, cognitive restraint and food cravings by using questionnaires and statistical analysis.

    At the end of the three-year study period, the researchers found that those in the HFE group lost more weight than those in the behavior therapy group. However, the differential in weight loss was modest, and all participants showed the familiar trend toward weight regain.

    “We failed to get them to translate our warnings into the kind of actions we were trying to get them to take,” Lowe said.

    The warnings did, however, have a positive — though unanticipated — effect. Cognitive restraint — defined by a participant’s ability to actively make healthy choices and measured with mediation analysis — showed the longest, most prolonged increase in the HFE participants, when compared to the other two treatment groups.

    This suggests that the researchers’ rhetoric about the difficulties of sustaining weight loss may have actually caused the participants in the HFE group to “push back” against this message and increase their vigilance over their eating, Lowe said.

    “That is, by questioning the usefulness of building self-control skills, the HFE treatment may have bolstered the very capacity it was meant to downplay — stronger self-control with regard to food,” the study authors write.

    Though surprising, these results have potentially clinically-useful implications. By emphasizing the many factors that make lasting weight loss so difficult, it may help motivate individuals to mentally and behaviorally cope with these factors, according to Lowe.

    “Rather than acting as cheerleaders giving facile encouragement, leaders of weight loss groups might serve their clients better by providing a more sobering description of the challenges participants face,” Lowe explained.

    However, since the participants in the HFE condition did not make greater changes to their home food environment, future studies should examine how to better improve and monitor this weight loss intervention, such as sending dieticians or other practitioners directly to clients’ homes for periodic visits.

    For Lowe, the study reinforces the challenging reality for those seeking to maintain weight loss — and makes a strong case for policies (such as Philadelphia’s beverage tax) that focus on preventing, rather than treating, the problem of obesity in the United States.

    “Once these conditions develop and you are continuing to live in the same obesogenic environment, it is unrealistic to expect that many people will be able to sustain a large weight loss,” he said. “Society ultimately needs to prevent these unhealthy weight gains before they occur.”


  2. Study suggests public commitment to weight loss goals can help with achieving them

    October 31, 2017 by Ashley

    From the American University press release:

    About those before and after selfies and public declarations of hitting the gym? New research co-authored by Dr. Sonya A. Grier, professor of marketing in the American University Kogod School of Business, confirms these announcements and progress updates are useful for the achievement of weight and fitness goals. “Weight Loss Through Virtual Support Communities: A Role for Identity-based Motivation in Public Commitment,” published in the Journal of Interactive Marketing, examines the role of virtual communities and public commitment to setting and weight loss goals.

    The study tracks two communities of weight loss groups, surgical and non-surgical over a four-year period. They found that participation and sharing of successes and setbacks in virtual support communities (VSC) is a key part of achieving goals through the public commitment to lose weight.

    “In our investigation of VSCs, we find social identity motivates public commitment in support of goal attainment,” the researchers write.

    Grier says, “The sharing of intimate information and photos about weight loss goals in virtual space is a key factor in motivating behaviors that fulfill that new thinner identity and thus helps people reach their goals.”

    Bloggers like Audrey* shared old photos in search of a “pretty and slim” version of herself.

    “Here is my picture of 28 years ago when I was young, pretty and slim,” Audrey* wrote in a post. “Makes me wanna cry… I can’t get any younger, but I sure can get closer to that weight! Stop crying, start losing weight, girl!”

    Others, like Darlene* shared milestones.

    “I have good news to report. My hard work of eating right and working out has paid off. I am now in ONDERLAND!!!! I weighed in this morning at 196lbs! YES, I did it. I reached my first goal to be under 200lbs and before my cruise on October 16th. I can’t believe I did it! I’m so proud of myself.”

    Ultimately, Grier says, VSCs allow for relative anonymity, accessibility, availability and flexibility in how users represent themselves on their journeys. The process of building community, even in relative anonymity helps with keeping participants motivated and accountable.

    “Not everyone can get the support they need from the people they interact with in person on a daily basis. It is helpful that technology can support community building and goal achievement in virtual spaces.”

    *Names have been changed.


  3. Mouse study suggests sense of smell affects metabolism

    July 26, 2017 by Ashley

    From the University of California – Berkeley press release:

    Our sense of smell is key to the enjoyment of food, so it may be no surprise that in experiments at the University of California, Berkeley, obese mice who lost their sense of smell also lost weight.

    What’s weird, however, is that these slimmed-down but smell-deficient mice ate the same amount of fatty food as mice that retained their sense of smell and ballooned to twice their normal weight.

    In addition, mice with a boosted sense of smell — super-smellers — got even fatter on a high-fat diet than did mice with normal smell.

    The findings suggest that the odor of what we eat may play an important role in how the body deals with calories. If you can’t smell your food, you may burn it rather than store it.

    These results point to a key connection between the olfactory or smell system and regions of the brain that regulate metabolism, in particular the hypothalamus, though the neural circuits are still unknown.

    “This paper is one of the first studies that really shows if we manipulate olfactory inputs we can actually alter how the brain perceives energy balance, and how the brain regulates energy balance,” said Céline Riera, a former UC Berkeley postdoctoral fellow now at Cedars-Sinai Medical Center in Los Angeles.

    Humans who lose their sense of smell because of age, injury or diseases such as Parkinson’s often become anorexic, but the cause has been unclear because loss of pleasure in eating also leads to depression, which itself can cause loss of appetite.

    The new study, published this week in the journal Cell Metabolism, implies that the loss of smell itself plays a role, and suggests possible interventions for those who have lost their smell as well as those having trouble losing weight.

    “Sensory systems play a role in metabolism. Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived,” said senior author Andrew Dillin, the Thomas and Stacey Siebel Distinguished Chair in Stem Cell Research, professor of molecular and cell biology and Howard Hughes Medical Institute Investigator. “If we can validate this in humans, perhaps we can actually make a drug that doesn’t interfere with smell but still blocks that metabolic circuitry. That would be amazing.”

    Riera noted that mice as well as humans are more sensitive to smells when they are hungry than after they’ve eaten, so perhaps the lack of smell tricks the body into thinking it has already eaten. While searching for food, the body stores calories in case it’s unsuccessful. Once food is secured, the body feels free to burn it.

    Zapping olfactory neurons

    The researchers used gene therapy to destroy olfactory neurons in the noses of adult mice but spare stem cells, so that the animals lost their sense of smell only temporarily — for about three weeks — before the olfactory neurons regrew.

    The smell-deficient mice rapidly burned calories by up-regulating their sympathetic nervous system, which is known to increase fat burning. The mice turned their beige fat cells — the subcutaneous fat storage cells that accumulate around our thighs and midriffs — into brown fat cells, which burn fatty acids to produce heat. Some turned almost all of their beige fat into brown fat, becoming lean, mean burning machines.

    In these mice, white fat cells — the storage cells that cluster around our internal organs and are associated with poor health outcomes — also shrank in size.

    The obese mice, which had also developed glucose intolerance — a condition that leads to diabetes — not only lost weight on a high-fat diet, but regained normal glucose tolerance.

    On the negative side, the loss of smell was accompanied by a large increase in levels of the hormone noradrenaline, which is a stress response tied to the sympathetic nervous system. In humans, such a sustained rise in this hormone could lead to a heart attack.

    Though it would be a drastic step to eliminate smell in humans wanting to lose weight, Dillin noted, it might be a viable alternative for the morbidly obese contemplating stomach stapling or bariatric surgery, even with the increased noradrenaline.

    “For that small group of people, you could wipe out their smell for maybe six months and then let the olfactory neurons grow back, after they’ve got their metabolic program rewired,” Dillin said.

    Dillin and Riera developed two different techniques to temporarily block the sense of smell in adult mice. In one, they genetically engineered mice to express a diphtheria receptor in their olfactory neurons, which reach from the nose’s odor receptors to the olfactory center in the brain. When diphtheria toxin was sprayed into their nose, the neurons died, rendering the mice smell-deficient until the stem cells regenerated them.

    Separately, they also engineered a benign virus to carry the receptor into olfactory cells only via inhalation. Diphtheria toxin again knocked out their sense of smell for about three weeks.

    In both cases, the smell-deficient mice ate as much of the high-fat food as did the mice that could still smell. But while the smell-deficient mice gained at most 10 percent more weight, going from 25-30 grams to 33 grams, the normal mice gained about 100 percent of their normal weight, ballooning up to 60 grams. For the former, insulin sensitivity and response to glucose — both of which are disrupted in metabolic disorders like obesity — remained normal.

    Mice that were already obese lost weight after their smell was knocked out, slimming down to the size of normal mice while still eating a high-fat diet. These mice lost only fat weight, with no effect on muscle, organ or bone mass.

    The UC Berkeley researchers then teamed up with colleagues in Germany who have a strain of mice that are supersmellers, with more acute olfactory nerves, and discovered that they gained more weight on a standard diet than did normal mice.

    “People with eating disorders sometimes have a hard time controlling how much food they are eating and they have a lot of cravings,” Riera said. “We think olfactory neurons are very important for controlling pleasure of food and if we have a way to modulate this pathway, we might be able to block cravings in these people and help them with managing their food intake.”


  4. Discrimination Based on Weight Doubles Health Risks

    October 21, 2016 by Ashley

    From the University of Rhode Island media release:

    obesityWe all know that carrying extra pounds can be bad for your health. Now a URI professor has found that how society treats overweight people makes matters worse.

    Maya Vadiveloo, assistant professor of nutrition and food sciences in the College of Health Sciences, and Josiemer Mattei, assistant professor of nutrition at Harvard University T.H. Chan School of Public Health, analyzed weight discrimination data from the long-term national study, Midlife Development in the United States.

    The researchers focused on respondents who reported regularly experiencing discrimination because of their weight. The study asked whether they were treated discourteously, called names, or made to feel inferior. Those who experienced weight discrimination over a 10-year period had twice the risk of high allostatic load, the cumulative dysfunction of bodily systems from chronic stress, they found. That stress can lead to heart disease, diabetes, inflammation and other disorders, increasing risk of death.

    “It is a pretty big effect,” Vadiveloo, of North Kingstown, says of the findings. “Even if we accounted for health effects attributed to being overweight, these people still experience double the risk of allostatic load because of weight discrimination.”

    The findings, published in the August issue of Annals of Behavioral Medicine, expose flaws in society’s approach to weight control, Vadiveloo says. “The main message is to be aware that the way we treat people may have more negative effects than we realize,” she says. “Our paper highlights the importance of including sensitivity and understanding when working with individuals with obesity and when developing public health campaigns.”

    People who experience weight discrimination often shun social interaction and skip doctor visits, she notes. “There is so much shaming around food and weight. We need to work together as a nation on improving public health and clinical support for individuals with obesity and targeting environmental risk factors,” she says. For example, Vadiveloo suggests developing strategies to make healthy foods affordable and creating safe places for people to be active.

    Vadiveloo hopes to address the topic in the classroom and revisit data from the nearly 1,000 respondents to explore whether having more social support or positive coping strategies reduces negative health effects of weight discrimination.