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The Role of a High-Fat Diet in Neurodevelopmental Disorders

Posted on by CNP Staff

The Diagnostic and Statistical Manual of Mental Disorders, version 5, DSM-5 for short, classifies autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disabilities, specific learning disorders, communication disorders, and motor disorders as neurodevelopmental disorders, or NDDs. This cluster of disorders is associated with abnormal brain development and impairments in cognition, speech and language skills, and social-emotional functioning.

A common feature of Neurodevelopmental Disorders or NDDs involves changes in synaptic plasticity in the brain. Synaptic plasticity is the brain’s process of modifying synaptic transmission in response to experiences and stimuli. 

While the underlying molecular mechanisms associated with changes in synaptic plasticity are only partially understood, lifestyle factors, like diet, also impact synaptic plasticity. In juvenile mice studies, a high-fat diet contributed to decreased hippocampal neurogenesis, impaired synaptic and cognitive function, and poor memory. By examining the molecular mechanisms affected by a high-fat diet, defined as a diet with a 30-50% fat content, Penna and his colleagues suspected there’s potential for understanding the molecular mechanisms associated with NDDs. 

Based on their review of study findings, Penna and his colleagues developed a diagram to illustrate potential molecular mechanisms connecting metabolic dysfunction of a high-fat diet to synaptic plasticity deficits related to NDDs.

A chronic, high-fat diet contributes to low-grade inflammation in the body. Persistent activation of the body’s inflammatory response system leads to the release of proinflammatory cytokines and other hormones into the bloodstream. This results in neuroinflammation. 

An associated dysfunction of neuroinflammation is changes in synaptic plasticity. These changes could be brought on by dysregulated local protein synthesis. In mice studies, a decrease in Brain-Derived Neurotrophic Factor (BDNF) — a neutrophin impacting synaptic transmission, was detected after consumption of a high-fat diet. The resulting hypothesis is that lowered levels of BDNF may lead to lowered protein synthesis at the synapse. This contributes to mitochondrial dysfunction, which is linked to neuroinflammation and alterations in synaptic plasticity found in NDDs and the effects of a high-fat diet.

   

References 

Penna, E., Pizzella, A., Cimmino, F., Trinchese, G., Cavaliere, G., Catapano, A., Allocca, I., Chun, J. T., Campanozzi, A., Messina, G., Precenzano, F., Lanzara, V., Messina, A., Monda, V., Monda, M., Perrone-Capano, C., Mollica, M. P., & Crispino, M. (2020). Neurodevelopmental disorders: Effect of high-fat diet on synaptic plasticity and mitochondrial functions. Brain Sciences, 10(11), 805. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7694125/

 

Mental Health Professionals Report Poor Literacy for Nutritional Medicine: International Survey

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Literacy among mental health professionals : Evidence supports the use of nutritional interventions for certain psychiatric symptoms, yet few studies have evaluated nutritional literacy among mental health professionals (MHPs). One such study is the online survey published by Mörkl et al. (2021), which gathered data from a sample of mental health professionals from 52 countries.

The survey collected data about general nutrition knowledge, nutrition education, learning opportunities, and the tendency to recommend or prescribe food supplements and diets. The sample included psychologists, psychiatrists, psychotherapists and MHPs in-training. Most participants were from Europe but the sample also included professionals from Asia, North America, Oceania, South America, and Africa. 

The majority of the participants (92.9%) wanted to expand their knowledge of Nutritional Psychiatry and only 0.8% of them rated their nutrition education as ‘very good’. In fact, most of the participants had no training in nutrition yet many did use nutrition approaches with their patients, with as many as 58.6% of them recommending supplements and 43.8% recommending diet strategies to their patients. Nutritional approaches to treatment were most often used for treating eating and affective disorders, followed by anxiety, psychotic, and obsessive-compulsive disorders. 

%learn about nutrition mental health %The Center for Nutritional Psychology
Diagram from: Mörkl, S., Stell, L., Buhai, D. V., Schweinzer, M., Wagner-Skacel, J., Vajda, C., … & Holasek, S. J. (2021). ‘An Apple a Day’?: Psychiatrists, Psychologists and Psychotherapists Report Poor Literacy for Nutritional Medicine: International Survey Spanning 52 Countries. Nutrients, 13(3), 822.

While most mental health professionals in the survey did not have any training in nutrition, the beliefs about nutrition reported by most of them align with what the data says. For instance, most believed that mental disorders are associated with poor nutrition and evidence shows that individuals with mental health problems often have an unhealthy lifestyle, including poor dietary choices, disordered eating behaviors, and nutritional deficiencies (Teasdale et al., 2019; Gill, 2021). Furthermore, the professionals interviewed often used nutritional approaches for affective disorders, a practice that is supported by research, including a meta-analysis of 16 randomized controlled trials which found that nutritional interventions significantly reduced symptoms of depression, especially when the interventions were provided by accredited nutritional professionals (Firth et al., 2019).

The authors of the survey hypothesized that psychiatrists may have a tendency to overrate their understanding of nutrition compared to other mental health professionals due to their medical training. This may imply that some of them may provide misguided nutrition advice due to lack of training. It is worth noticing that, in the US, for example, only 40% of medical schools reach the goal of teaching 25 h of nutrition in preclinical years (Adams, Lindell, Kohlmeier & Zeisel, 2006).

Two main points can be made out of the results of this survey. First, many mental health professionals do not use nutritional interventions, either because they are not aware of the relevance of such interventions or because they do not have the training to do it. Second, while most mental health experts do use nutritional approaches to treatment, many may lack the knowledge necessary to provide adequate nutritional counselling.  Introducing nutrition education in the educational curricula of mental health professionals may improve the quality of mental health services and, consequently, of  mental health outcomes.

 

References

Adams, K. M., Lindell, K. C., Kohlmeier, M., & Zeisel, S. H. (2006). Status of nutrition education in medical schools. The American Journal of Clinical Nutrition, 83(4), 941S-944S.

Gill, R., Tyndall, S. F., Vora, D., Hasan, R., Megna, J. L., & Leontieva, L. (2021). Diet Quality and Mental Health Amongst Acute Inpatient Psychiatric Patients. Cureus, 13(1), e12434. https://doi.org/10.7759/cureus.12434

Firth, J., Marx, W., Dash, S., Carney, R., Teasdale, S. B., Solmi, M., … & Sarris, J. (2019). The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials. Psychosomatic Medicine, 81(3), 265.

Mörkl, S., Stell, L., Buhai, D. V., Schweinzer, M., Wagner-Skacel, J., Vajda, C., … & Holasek, S. J. (2021). ‘An Apple a Day’?: Psychiatrists, Psychologists and Psychotherapists Report Poor Literacy for Nutritional Medicine: International Survey Spanning 52 Countries. Nutrients, 13(3), 822. https://www.mdpi.com/2072-6643/13/3/822

Teasdale, S. B., Ward, P. B., Samaras, K., Firth, J., Stubbs, B., Tripodi, E., & Burrows, T. L. (2019). Dietary intake of people with severe mental illness: systematic review and meta-analysis. The British Journal of Psychiatry, 214(5), 251-259.

 

Is Food Insecurity Affecting College Students’ Mental Health and Academic Performance?

Posted on by CNP Staff

Food insecurity affects over 13 million households in the U.S. alone. Food insecurity means having minimal or no access to nutritious and safe foods. While this affects every age bracket of the population ranging from infants to elderly, a recent study by Martinez, Esaryk, Moffat, and Ritchie (2020) wanted to examine the particular effect of food insecurity on the academic performance and mental health of college students.

Costs of living expenses are on the rise and college students are one of numerous populations affected. Many students do not have the ability to live on limited resources and may feel shame in asking for help. Previous studies have shown that in addition to enduring uncomfortable feelings of physical hunger, students experiencing food insecurity also show decreased academic performance. Students as a population report higher levels of depressive feelings and feelings of isolation. 

In the study at hand, Martinez et al. examined the association between food insecurity and academic performance and mental health. Over 8,000 students from the University of California public college system were selected to complete an online survey assessing Grade Point Average (GPA), food insecurity level, and student mental health.  

Food security was assessed through a validated US Department of Agriculture (USDA) 6-item short survey. The USDA short survey categorized food insecurity in the following categories: food secure, low food secure, and very low food secure. 

Students reported their grade point average (G.P.A.), and the National College Health Assessment II survey captured mental health ratings through self-reported feelings of hopelessness, overwhelm, exhaustion, loneliness, sadness, anger, and depression.

Food insecurity affects Students: Of the students included in the study, findings showed that 40% experienced food insecurity. In terms of grades, 51% of food-secure students had a cumulative A average, whereas only 30% of food-insecure students had a cumulative A average. Of those students having a C grade average, 19% of them were food insecure compared to 9% of students that were food-secure.

In terms of mental health indicators, food insecure students had significantly higher proportions of mental health indicators compared to food-secure students. 

These findings show that students experiencing hunger from food insecurity have challenges with concentration that could be affecting their academic performance. The authors state that academic performance and mental health can improve if food insecurity is addressed, and that higher education campus services can be a good place to instill intervention programs to help address food insecurity among university students.

 

References

Martinez, S. M., Frongillo, E. A., Leung, C., & Ritchie, L. (2020). No food for thought: Food insecurity is related to poor mental health and lower academic performance among students in California’s public university system. Journal of Health Psychology, 25(12), 1930–1939. https://doi.org/10.1177/1359105318783028

Coleman-Jensen, A., Rabbitt, M. P., Gregory, C. and Singh, A. (2020). Household Food Security in the United States in 2019. https://www.ers.usda.gov/webdocs/publications/99282/err275_summary.pdf?v=4695.5

 

Suggested Further Reading

Martinez, S. M., Esaryk, E. E., Moffat, L., & Ritchie, L. (2021). Redefining Basic Needs for Higher Education: It’s More Than Minimal Food and Housing According to California University Students. American Journal of Health Promotion, 890117121992295. Advance online publication. https://doi.org/10.1177/0890117121992295

Wolfson, J. A., Garcia, T., & Leung, C. W. (2021). Food Insecurity Is Associated with Depression, Anxiety, and Stress: Evidence from the Early Days of the COVID-19 Pandemic in the United States. Health Equity, 5(1), 64–71. https://doi.org/10.1089/heq.2020.0059

 

Does Exposure to Food Advertisements Influence Dietary Intake?

Posted on by CNP Staff

The diet-sensory-perceptual relationship (DSPR) is a central component of the diet-mental health relationship (DMHR) — and one of the six major elements defining the field of nutritional psychology (NP). The DSPR examines the interconnected relationship between our sensory-perceptual experience and how it connects with our dietary choices and intake behaviors.Food advertising (viewing food advertisements on television or the internet) influences our dietary intake via the DSPR. While we discuss this at length in the Diet Sensory-Perceptual Module within NP 110, let’s review a study exploring the relationship between advertisements and dietary intake by Zimmerman and Shimoga (2014).

In this study, the authors assessed the impact of TV advertisements on participants’ food choices. Participants were exposed to: 1) food advertising + a cognitively demanding task; 2) food advertising + a non–cognitively demanding task; 3) non-food related advertisement while performing a cognitively demanding task; or 4) non-food advertising task before performing a non-cognitively demanding task. The outcomes measured were the number and calorie contents of the unhealthy snacks selected by the participants.

The data revealed that those participants exposed to food advertising chose 28% more unhealthy snacks than those who encountered the non-food advertising (leading to a 65 kcal increase in dietary intake).

While the different advertisements did not significantly affect the individuals assigned to the less cognitively demanding task, there was a large and significant influence of advertising in the participants completing the cognitively demanding task. Those in the cognitively demanding task exposed to food-related advertisements ate 43% more unhealthy snacks, taking in 94 more total calories, compared to the participants who saw non-food advertisements.

This study demonstrated that televised food advertising strongly influences people’s food choices, particularly when these individuals are challenged cognitively. Other findings demonstrate that advertisements (through both the internet and television) influence dietary intake choices in both the adult and child/adolescent population.

While findings like these are instrumental for increasing our understanding of the intimate relationship between dietary intake and psychological health, it is necessary to build a conceptual framework within which we can house these findings. Nutritional Psychology is the field of science dedicated to building this structure.

You can learn more about the DSPR, as well as the other five key elements informing the DMHR, in NP 110: Introduction to Nutritional Psychology Methods.

 

References

Zimmerman, F., & Shimoga, S.V. (2014). The effects of food advertising and cognitive load on food choices. BMC Public Health, 14, 342-342. https://doi.org/10.1186/1471-2458-14-342

Child Nutritional Psychology: Diet Increases Risk of Mental Health Issues in Adulthood

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Cardiometabolic disorders often occur alongside certain mental health conditions like depression and psychosis. But these disorders are generally deemed an issue for the aging population and not for children, which subsequently leads to indifference regarding the importance of children’s diets.

A study published on the 13th of January 2021 may change this narrative. Following nearly 15,000 children from the ages of 1 to 24 years old, researchers measured fasting insulin levels at age 9, 15, 18, and 24 years of age, alongside repeatedly measuring body mass index.

Importance of children’s diets in relation with Body mass index: When the children reached the age of 24, they completed a semi-structured psychosis-like symptom interview which was used to identify psychotic experiences and symptoms of depression.

After adjusting for confounding variables like sex at birth, race/ethnicity, paternal social class, childhood emotional and behavioral problems along with lifestyle behaviors including smoking, physical activity, alcohol use, substance use, sleep problems, and average calorie intake, what they found was particularly interesting.

Children who had persistently high insulin levels beginning at age 9 were five times more likely to be at risk for psychosis and three times more likely to be diagnosed with a psychotic disorder at 24.

Not only that, but children who had a significant increase in their body mass index around puberty were four times more likely to develop depressive symptoms or experience a depressive episode by the age of 24.

During adolescence, the brain undergoes extensive change and maturation. The area essential for cognitive control is the final region to reach full maturity. Whilst this region is still developing, it is less able to exert control over reward-driven behaviours, like consuming calorie-dense food. Over-consumption of calorie-dense foods is the leading cause of obesity. Unfortunately, the persistent and excessive consumption of calorie-dense foods can lead to changes in the structure and function of the very same region — the prefrontal cortex — which can then result in altered neurotransmitter systems. The development of balance in these systems is in fact critical to obtaining optimal brain function in adulthood.

Appropriate nutrition during this period of neurodevelopment is vital for brain health. Find a link to this study, as well as additional research connecting diet with children’s psychological functioning in the Diet, Depression & Anxiety research category within CNP’s Parent Research Library.

 

References

Perry, B.I., Stochl, J., Upthegrove, R., et al. (2021). Longitudinal Trends in Childhood Insulin Levels and Body Mass Index and Associations With Risks of Psychosis and Depression in Young Adults. JAMA Psychiatry. DOI:10.1001/jamapsychiatry.2020.4180

Our Cognitive-Behavioral Relationship with Junk Food — Interoceptive Awareness to the Rescue?

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Our diet-mental health relationship (DMHR) is complex. When it comes to taking control of our dietary intake patterns (from the inside out) and making conscious decisions to support our mood and psychological health, research shows that increasing something called our Interoceptive Awareness (IA) is a great place to start (Herbert et al., 2013).Many people know intuitively that eating unhealthy junk foods can lead them on a path to making more unhealthy food choices, but research is beginning to reveal the complex cognitive-behavioral processes showing us why. An increasing number of studies reveal that consuming processed sugary foods high in fat and sugar leads to changes in our brain’s cognitive-behavioral processes that change our brain function and influence us to eat more high fat/high sugar (HFHS) foods (Stevenson et al., 2020). This and other “reward-based” processes create “neuroadaptations” in our brain that further influence our eating behaviors and reinforce our food choices.

Junk food and cognitive-behavioral processes

A study by Dr. Stevenson and his colleagues found that merely adding extra junk food to our diet for as little as 7 days impairs our ability to control our appetite. A growing body of research is demonstrating that the structure in the brain responsible for this particular cognitive-behavioral process is the hippocampus. The hippocampus is best known for its role in learning and memory, and as it turns out, is the part of the brain that is most highly susceptible to influence by a HFHS diet.

This study, which was the first to demonstrate a causal role in the ability of a HFHS to directly affect hippocampal functioning, shows that the cognitive processes affected resulted in impaired appetite control, leading to an increased desire to consume HFHS foods —even when full. It turns out that in this same study, those who were eating the junk food addition in their diet performed worse on tests of learning and memory — processes of cognition that are controlled by the hippocampus.

Why are learning and memory involved in regulating appetite and driving our eating behavior? When we consume foods rich in processed fat and sugar, our hippocampus — the part of our brain involved in learning and memory activates brain functions that affect cognitive-behavioral processes involving liking/wanting, learning/remembering, and anticipating (many factors that relate to our cognitive control mechanisms and ensuing dietary intake behaviors).

These foods also stimulate reward pathways in the brain which release dopamine. Dopamine is the neurotransmitter involved in feeling pleasure, which is released in anticipation of a reward (Attuquayefio et al., 2017). This is particularly important because it enhances reward-related memories, strengthening memory-related synapses in the brain. 

This high-sensory experience of anticipation, pleasure and reward is encoded into our brain’s wiring of memories, making us more susceptible to choosing HFHS foods in the future. For some of us, if we listen carefully to our body’s sensations, we can become aware of what we feel in this process. 

 

What is interoception and what role does it play in this process?

Interoception — our body’s physiological internal sensory system providing us with information about the internal state of our body (Sharp et al., 2018) — is one of the six elements informing the field of Nutritional Psychology. The intrinsic approach mentioned above involves increasing our Interoceptive Awareness (IA) — our ability to identify, access, understand, and respond appropriately to our internal physiological signals. 

It turns out that IA can be an important path to self-regulation. By using IA to connect to our perception of the internal state of our body, we can become more aware of the highly orchestrated dance between our dietary intake, cognitive, and behavioral processes.

To learn more about the hippocampus’ role in regulating appetite, watch our Diet-Mental Health Break #1. 

To learn more about how cognition, behavior, and interoceptive processes play a role in the DMHR, take 110: Introduction to Nutritional Psychology Methods. 

 


References

Attuquayefio, T., Stevenson, R. J., Oaten, M. J., & Francis, H. M. (2017). A four-day western-style dietary intervention causes reductions in hippocampal-dependent learning and memory and interoceptive sensitivity. PloS One, 12(2), e0172645. 

Herbert, B. M., Blechert, J., Hautzinger, M., Matthias, E., & Herbert, C. (2013). Intuitive eating is associated with interoceptive sensitivity. Effects on body mass index. Appetite, 70, 22-30.

Powell A. (2018). Harvard researchers study how mindfulness may change the brain in depressed patients. Harvard Gazette. https://news.harvard.edu/gazette/story/2018/04/harvard-researchers-study-how-mindfulness-may-change-the-brain-in-depressed-patients/

Sharp, P. B., Sutton, B. P., Paul, E. J., et al. (2018). Mindfulness training induces structural connectome changes in insula networks. Sci Rep. 8(1):1-10.

Stevenson RJ, Francis HM, Attuquayefio T, et al. Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet. R Soc Open Sci. 2020;7(2):191338.

Diet Quality and Mental Health Amongst Acute Inpatient Psychiatric Patients

Posted on by CNP Staff

Taking into consideration the global shift to a diet rich in refined carbohydrates, this exploratory study examined the self-reported dietary habits of psychiatric inpatients in the psychiatric unit of an academic hospital.

After gathering a detailed diet history of patients’ food habits, findings were compared to a Mediterranean dietary index to assess patient dietary patterns. Findings showed that 75% of the psychiatric inpatients had an unhealthy diet, and that inpatients with schizophrenia had highly significant increased sugar consumption.

The study authors expressed concern that unhealthy dietary habits cause deficiencies in essential nutrients and minerals and can exacerbate mental illnesses. They also expressed that while the causes of mental health conditions are multifactorial and can be partially attributed to the social impairment and diminished quality of self-care resulting from mental illness, improved dietary habits may contribute to more rapid symptoms resolution and acute stabilization in short-stay psychiatric inpatient units.

The authors also conclude that while unhealthy food and inactivity have been part of the culture of mental health treatment historically, recommendations and encouragement to follow national guidelines for dietary and exercise practices should be part of care for all people with mental illness.

The authors further state that while mental health practitioners may not feel competent to provide advice on nutrition and diet, the evidence suggests that detailed advice may not be necessary. Read the full, original study here.

 

References

Gill, R., Tyndall, S. F., Vora, D., Hasan, R., Megna, J. L., & Leontieva, L. (2021). Diet Quality and Mental Health Amongst Acute Inpatient Psychiatric Patients. Cureus, 13(1), e12434. https://doi.org/10.7759/cureus.12434

A New Path Forward: Introduction to Nutritional Psychology Methods (NP 110)

Posted on by CNP Staff

Thirty years ago, there existed no university-level education in how diet and nutrients relate to human behavior and psychological functioning. Over time, an increasing number of students, professionals, practitioners, and researchers realized that there is indeed a connection between what we eat and how we feel. They sought to educate and train themselves in the science of this connection, wondering why their respective fields hadn’t formally acknowledged it, nor provided an educational curriculum on this subject.

Today, an abundance of research supports and strengthens our understanding of this “food-mood” link, but it is spread across many countries, disciplines, and scientific journals. nutritional psychology (NP) is the field of study that unites these findings and recognizes the elements needed to define the relationship between nutrition and psychological functioning. 

Here at The Center for Nutritional Psychology, we are consolidating the wealth of NP-related research and information. We are using it to support the development of methods, education, and training in NP. We are committed to paving the path for professionals, educators, parents, researchers, and everyone else wishing to learn to use NP to improve psychological functioning.

Launching March 2021, NP 110: Introduction to Nutritional Psychology Methods will be the first in a series of educational courses based on the latest scientific findings relating to NP. This course will…

  • Introduce conceptualization, methods, and research structures informing the field
  • Introduce the six elements of the field of NP: the psychological, behavioral, cognitive, perceptual, interoceptive, and psychosocial
  • Provide administrative information helpful in taking this course 
  • Introduce preliminary Scope of Practice Guidelines for implementing this knowledge in a professional setting

While designed primarily for students and mental health, nutrition, and allied health professionals, this course is open to anyone wishing to learn the science of how dietary intake affects mood, behavior, and psychological functioning. 

NP 110 Introduction to Nutritional Psychology Methods will be the first of many courses examining the elements that inform our relationship with food and its nutrients. 

Welcome to the beginning of your formal educational journey in nutritional psychology.

Nutritional Psychology Influences of Diet on Perception

Posted on by CNP Staff

The global diabetes prevalence in 2019 is estimated to be 9.3% (463 million people), rising to 10.2% (578 million) by 2030 and 10.9% (700 million) by 2045.1 While diabetes is generally approached from a biomedical model, this study demonstrated that psychological and perceptual factors can significantly influence our physiology when it comes to blood glucose levels.

Let’s begin by understanding the process of human perception. What is perception? For the purpose of understanding the study at hand, perception involves 1) the taking in of information through our senses (i.e., our eyes or ears) and 2) our brain’s interpretation of this information into something that has personal meaning.  An example would be our perception of the color red being “hot”, or the color green meaning “go”.

Peoples’ perceptions differ for several reasons, and we each ascribe a different meaning to the same objects, smells, sights, sounds, and feelings, and sensations. A classic example of perception used in psychology involves the figure/foreground ‘face or cup’ illustration. Do you see two faces in these images or a cup?

Figure 1. Perception Illustration: Face or Cup?
%learn about nutrition mental health %The Center for Nutritional Psychology

Study

This study examined whether our perception of how much sugar a drink contained (as indicated by its label) could influence our physiological response to that drink. The study involved: 1) a diabetic patient population, 2) food labels listing different amounts of sugar in a juice drink (all contained the same amount), and 3) examination of the psychological and perceptual factors influencing the participants’ physiological reactions in response their perception of how much sugar was in the drink.

In other words, can our perception of the amount of sugar shown on a drink label affect our physiological reaction to that drink?

Thirty participants with type 2 diabetes were divided into two groups and given a sugar-sweetened beverage. One group was shown a nutrition label that reported zero grams of sugar in the beverage, while the other was shown a nutrition label that reported 30 grams of sugar. In reality, all participants received the same exact beverage containing 15 grams of sugar.

Figure 2. The experiment’s manipulated nutrition labels2
%learn about nutrition mental health %The Center for Nutritional Psychology

The team measured blood glucose levels 4 times throughout the experiment: immediately before consumption and 20, 40, and 60 minutes after consumption.

Findings

They found that the participants who were shown the high sugar label had higher levels of glucose in their bloodstream than those who thought they were drinking a sugar-free beverage. Meaning that the participants’ blood glucose values changed exclusively due to their psychological perception of the sugar content, rather than the amount of sugar they actually consumed.

Perception of sugar intake influenced physiological reaction
%learn about nutrition mental health %The Center for Nutritional Psychology

 

While study results showed that just the perception of sugar content affected changes in diabetic participants’ blood glucose levels, it also revealed that their perception of how much sugar was included in the drink was influenced by their underlying emotional processes.

Namely, those whose blood glucose levels increased the most in response to the drink’s perceived sugar content, were those who were influenced more by external cues in their environment — like whether it was time to eat, or if other people were eating. Those who were driven more by their internal (or interoceptive) cues of hunger, had a more accurate perception of the drink’s actual sugar content. And this more accurate perception was more aligned with an accurate physiological response to the drink’s sugar content.

Conclusion

These findings help us understand that psychological and physiological processes aren’t independent of each other like we originally thought. See the CNP Diet-Mental Health Break created on this study in the CNP Video Research Library. We thank Dr. Chanmo Park for his personal support in providing editing assistance for the DMHB script.

Citations

1. Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas, 9th edition https://www.sciencedirect.com/science/article/pii/S0168822719312306

2. Park, C., Pagnini, F., & Langer, E. (2020). Glucose metabolism responds to perceived sugar intake more than actual sugar intake. Scientific reports,10(1), 15633.

 

 

Nutritional Psychology: Can a 1-Week Junk Food Diet Change Your Brain and Lead to Overeating?

Posted on by CNP Staff

Researchers are zeroing in on whether high-fat, high-sugar foods can impact our brain, and influence our eating choices. It turns out that they can and do, and the Hippocampus, a major structure within our brain, is one of junk food’s favorite targets.

We were excited when we heard about this recently published study. We knew it belonged in the CNP Diet and Brain Research Category, and would be the perfect flagship study for our first Diet-Mental Health Break (DMHB). CNP’s DMHBs are quick 2-3 animated cartoons that take cutting-edge research studies and turn them into highly palatable (no pun intended) animations that support conceptualization in the field of Nutritional Psychology (NP).

This animated series is designed for inclusion within CNP’s Nutritional Psychology curriculum and can be used by educators, mental health professionals, dietitians, and other interested individuals to develop an understanding of how diet affects mood, behavior, and mental health. This increased understanding can lead to tools to better support our Diet-Mental Health Relationship (DMHR).

The lead author of this study, Dr. Richard Stevenson from Macquarie University in Sydney, Australia, has been investigating the effects of what are called “highly-palatable foods” on a part of our brain called the hippocampus. Investigation in this area had been done before, but this study was only the second to demonstrate whether exposure to a western-style diet actually causes hippocampal impairment (the first study on this topic can be found here).

Study Methodology

Dr. Stevenson’s study included 102 healthy university students, all who regularly ate a healthy, balanced diet. For the duration of the experiment, half of the group ate their regular balanced diet, while the other half ate their balanced diet plus additional portions of junk food each day.

At the end of the week, both groups’ hippocampal functioning was tested to see whether the junk food added to their diet changed their desire for these foods. The hippocampus is the part of our brain that helps us to learn, remember, and control our appetite.

Study Findings

The participants’ desire to eat the highly palatable foods was significantly increased to the point that they continued to eat even after they were full. This study showed that when we eat junk-style foods – foods high in processed sugars and fats – the high-sensory experiences of anticipation, pleasure, and reward are encoded into our memory. This memory influences what we like and want to eat, and how much. It sets us on a path to want and like more highly stimulating junk foods, and to eat more of them. In the end, this study demonstrated that just one week of added junk food significantly impaired the ability to control one’s appetite. Food for thought…

The full research study by Dr. Stevenson and his team, entitled “Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet,” can be found here. Watch CNP’s animated Diet-Mental Health Break (DMHB) video on this study here.

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