Adolescent obesity and dietary decision making—a brain-health perspective

How do we harness adolescent values in designing health behaviour change interventions? A qualitative study

OBJECTIVES

Adolescent health behaviours do not support optimal development. Adolescents are reportedly difficult to engage in health behaviour improvement initiatives. Little is known about what adolescents value in relation to diet and physical activity or how best to target these in health interventions. This study explored adolescents' values in relation to diet and physical activity and how these values can inform health intervention design.

DESIGN

Qualitative semi-structured interviews explored adolescents' lives, what they thought about diet and physical activity and what might support them to improve their health behaviours.

METHODS

A total of 13 group interviews were conducted with 54 adolescents aged 13-14 years, of whom 49% were girls and 95% identified as White British. Participants were recruited from a non-selective secondary school in a large southern UK city. Inductive thematic analysis was used to identify key adolescent values.

RESULTS

Adolescents valued being with their friends, doing what they enjoyed and were good at; being healthy was important to them but only if achievable without compromising other things that are important to them. The need to be healthy was not aligned with adolescents' basic psychological needs, nor their strongly held priorities and values.

CONCLUSIONS

Health is not a motivating factor for adolescents; therefore, interventions designed solely to improve health are unlikely to engage them. Instead, interventions that align with the values and priorities specified by adolescents are more likely to be effective in supporting them to eat well and be more active.

Association between obesity and neurocognitive function in survivors of childhood acute lymphoblastic leukemia treated only with chemotherapy

BACKGROUND

Neurocognitive impairment and obesity are common adverse sequelae in survivors of childhood acute lymphoblastic leukemia (ALL); however, the association has not been investigated.

METHODS

Neurocognitive function was evaluated once in survivors of ALL who were at least 8 years old and 5 years from their diagnosis. In a cross-sectional analysis, the associations with the body mass index (BMI) category and Z score were examined. A longitudinal analysis used the overweight/obesity area under the curve (AUC), which was determined via the trapezoidal rule by a sum of the integrals defined by the BMI Z score at each time point and the time intervals of the BMI measurement.

RESULTS

For 210 survivors, the median BMI Z score at diagnosis was 0.17, which increased to 0.54 at the end of induction and to 0.74 at the neurocognitive assessment. In the cross-sectional analysis, overweight/obese survivors scored significantly lower than others on the measures of executive function (cognitive flexibility, planning, verbal fluency, working memory, and spatial construction; all P < .05), attention (attention span and risk taking; all P < .05), and processing speed (visual motor coordination, visual speed, and motor speed; all P < .05). In the longitudinal analysis, when the treatment period was subdivided into 4 time periods (induction, consolidation, early maintenance, and late maintenance), a greater overweight/obesity AUC during induction therapy was associated with worse cognitive flexibility (P = .01) and slower motor speed (P = .02), which persisted throughout the treatment.

CONCLUSIONS

Overweight/obesity was significantly associated with neurocognitive impairment during long-term follow-up, and this association started early in treatment for ALL. Novel early interventions to provide cognitive training and prevent weight gain are required for patients at risk.

Academy of Nutrition and Dietetics: Revised 2020 Standards of Practice and Standards of Professional Performance for Registered Dietitian Nutritionists (Competent, Proficient, and Expert) in Eating Disorders

Eating disorders (ED) are complex mental illnesses and are not a result of personal choice. Full recovery from an ED is possible. The severity and inherent lethality of an ED is undisputed, and the role of the registered dietitian nutritionist (RDN) is essential. Clinical symptomology presents at varying developmental milestones and is perpetuated through a sociocultural evaluation of beauty and drive for ascetic idealism. ED are globally prevalent in 4.4% of the population aged 5 to 17 years, yet affect individuals across the entire lifespan, including all cultures and genders. The Behavioral Health Nutrition Dietetic Practice Group, along with the Academy of Nutrition and Dietetics Quality Management Committee, revised the Standards of Practice (SOP) and Standards of Professional Performance (SOPP) for RDNs in Eating Disorders. Including the RDN in ED treatment is vital for all levels of care. The RDN must be perceptive to negative symptoms indicative of psychological triggers when exploring food belief systems, patterns of disinhibition, and nutrition misinformation with clients. Through a conscious awareness of medical, psychological, and behavioral strategies, the implementation of the SOP and SOPP supports a dynamic and holistic view of ED treatment by the RDN. The SOP and SOPP are complementary resources for RDNs and are intended to be used as self-evaluation tools for assuring competent practice in ED and for determining potential education, training, supervision, and mentorship needs for advancement to a higher practice level in a variety of settings.

Age-dependent and region-specific alteration of parvalbumin neurons, perineuronal nets and microglia in the mouse prefrontal cortex and hippocampus following obesogenic diet consumption

Emergent evidence demonstrates that excessive consumption of high fat and high sugar (HFHS) diets has negative consequences on hippocampal and prefrontal cortex (PFC) function. Moreover, the delayed maturation of the PFC including the late development of parvalbumin-expressing (PV) interneurons and perineuronal nets (PNNs) may promote vulnerability to HFHS diet-induced nutritional stress. However, the young brain may have some resistance to diet-induced neuroinflammation. Thus, we examined the impact of a HFHS diet commencing either in adolescence or adulthood in male mice. PV interneurons, PNNs and microglia were assessed using immunohistochemistry. We observed greater numbers of PV neurons and PNNs in the hippocampus and the prelimbic and infralimbic PFC in adult mice in comparison to our younger cohort. Mice that consumed HFHS diet as adults had reduced numbers of hippocampal PV neurons and PNNs, which correlated with adiposity. However, we saw no effects of diet on PV and PNNs in the PFC. HFHS diet increased microgliosis in the adult cohort, and morphological changes to microglia were observed in the PFC and hippocampus of the adolescent cohort, with a shift to activated microglia phenotypes. Taken together, these findings demonstrate different regional and age-specific effects of obesogenic diets on PV neurons, PNNs and microglia.

Appetite self-regulation declines across childhood while general self-regulation improves: A narrative review of the origins and development of appetite self-regulation

This narrative review discusses the origins and development of appetite self-regulation (ASR) in childhood (from infancy to age 6 or 7 years). The origins, or foundations, are the biological infrastructure associated with appetite regulation and appetite self-regulation. Homeostatic regulation in infancy is examined and then evidence about developmental change in components of ASR. The main ASR-related components covered are: delay-of-gratification, caloric compensation, eating in the absence of hunger, food responsiveness/hedonics and fussy eating. The research included behavioral measures, parent-reports of appetitive traits and fMRI studies. There were two main trends in the evidence: a decline across childhood in the components of ASR associated with food approach (and therefore an increase in disinhibited eating), and wide individual differences. The decline in ASR contrasts with general self-regulation (GSR) where the evidence is of an improvement across childhood. For many children, bottom-up automatic reactive processes via food reward/hedonics or food avoidance as in fussy eating, appear not to be matched by improvements in top-down regulatory capacities. The prominence of bottom-up processes in ASR could be the main factor in possible differences in developmental paths for GSR and ASR. GSR research is situated in developmental science with its focus on developmental processes, theory and methodology. In contrast, the development of ASR at present does not have a strong developmental tradition to access and there is no unifying model of ASR and its development. We concluded (1) outside of mean-level or normative changes in the components of ASR, individual differences are prominent, and (2) there is a need to formulate models of developmental change in ASR together with appropriate measurement, research designs and data analysis strategies.

Western Diet Consumption During Development: Setting the Stage for Neurocognitive Dysfunction

The dietary pattern in industrialized countries has changed substantially over the past century due to technological advances in agriculture, food processing, storage, marketing, and distribution practices. The availability of highly palatable, calorically dense foods that are shelf-stable has facilitated a food environment where overconsumption of foods that have a high percentage of calories derived from fat (particularly saturated fat) and sugar is extremely common in modern Westernized societies. In addition to being a predictor of obesity and metabolic dysfunction, consumption of a Western diet (WD) is related to poorer cognitive performance across the lifespan. In particular, WD consumption during critical early life stages of development has negative consequences on various cognitive abilities later in adulthood. This review highlights rodent model research identifying dietary, metabolic, and neurobiological mechanisms linking consumption of a WD during early life periods of development (gestation, lactation, juvenile and adolescence) with behavioral impairments in multiple cognitive domains, including anxiety-like behavior, learning and memory function, reward-motivated behavior, and social behavior. The literature supports a model in which early life WD consumption leads to long-lasting neurocognitive impairments that are largely dissociable from WD effects on obesity and metabolic dysfunction.

Female adolescents with overweight and obesity share their perspectives on the clinical setting and weight management

The clinical setting remains a strategic environment for early assessment, identification and treatment of adolescents with obesity. Yet, healthcare providers' (HCPs) efforts have been unsuccessful in improving physical activity, nutritional intake or body mass index in adolescents with obesity. Obesity is a chronic condition that influences how patients interact with HCPs and experience ambulatory healthcare appointments. However, it is unknown how female adolescents with obesity perceive the clinical setting, especially regarding weight management. The purpose of this study was to explore the perceptions of female adolescents with obesity regarding health and weight management in the clinical setting. Using a qualitative design, 28 English-speaking female adolescents, 13 to 19 years of age, with a body mass index ≥85th percentile for height and weight participated in individual interviews. Results demonstrate that adolescents with obesity desire to be recognized as unique individuals and to be involved in their own health conversations. The participants reported that their health care was inadequate when they received impersonal and vague advice from HCPs on weight loss. Weight-related communication was best received in a kind and empathetic manner, with a focus on improving one's health (instead of losing weight). Adolescents in this study articulated the components of healthy eating and physical exercise, yet were unable to synthesize this knowledge into specific dietary practices and daily physical activities. The insights derived from female adolescents with obesity provide guidance on how HCPs can improve their relationship and engage the adolescent in weight-based discussions. Concrete, actionable recommendations are provided for providers who work with female adolescents who are overweight or obese.

Structural Brain Changes Associated with Overweight and Obesity

Obesity is a global health problem with a broad set of comorbidities, such as malnutrition, metabolic syndrome, diabetes, systemic hypertension, heart failure, and kidney failure. This review describes recent findings of neuroimaging and two studies of cell density regarding the roles of overnutrition-induced hypothalamic inflammation in neurodegeneration. These studies provided consistent evidence of smaller cortical thickness or reduction in the gray matter volume in people with overweight and obesity; however, the investigated brain regions varied across the studies. In general, bilateral frontal and temporal areas, basal nuclei, and cerebellum are more commonly involved. Mechanisms of volume reduction are unknown, and neuroinflammation caused by obesity is likely to induce neuronal loss. Adipocytes, macrophages of the adipose tissue, and gut dysbiosis in overweight and obese individuals result in the secretion of the cytokines and chemokines that cross the blood-brain barrier and may stimulate microglia, which in turn also release proinflammatory cytokines. This leads to chronic low-grade neuroinflammation and may be an important factor for apoptotic signaling and neuronal death. Additionally, significant microangiopathy observed in rat models may be another important mechanism of induction of apoptosis. Neuroinflammation in neurodegenerative diseases (such as Alzheimer's and Parkinson's diseases) may be similar to that in metabolic diseases induced by malnutrition. Poor cognitive performance, mainly in executive functions, in individuals with obesity is also discussed. This review highlights the neuroinflammatory and neurodegenerative mechanisms linked to obesity and emphasizes the importance of developing effective prevention and treatment intervention strategies for overweight and obese individuals.

Children as food designers: The potential of co-creation to make the healthy choice the preferred one

According to the WHO, childhood obesity is one of the most serious public health challenges of the twenty-first century. In this context, finding ways to make the healthier food choices the preferred ones can be a valuable contribution to solving this multifaceted problem. Sensory and consumer science offers a wide range of tools that can support the development of healthy and well-accepted food alternatives. In traditional sensory and consumer science, children would be involved in the product development process either as testers or informants. However, in our opinion, it would be valuable to extend their role to co-creators or co-designers, an approach already more established in the field of innovation and design, where children actively participate in the idea generation and development of healthy food that they will like and choose. Our own experience has shown that involving children in the idea-generation step for healthy food can be highly motivating and stimulating for them. In this opinion article, we discuss why it is important to include children actively as a relevant consumer segment in product development and suggest a process and methods that could be valuable for brainstorming about food ideas with children.

Evaluation of Health-Habits with the S.M.A.R.T. Questionnaire: An Observational Study

The civil education approach uses sports practise as a preventive intervention to increase self-awareness and to help modulate emotion in adolescents. Indeed, sports participation results in a better quality of life, more favourable cardio-metabolic and sleeping profiles and a healthier body composition. Adolescents involved in sport activities also report a higher level of social and emotional skills, and reduced mental health distress. However, the Italian school’s program provides only two hours weekly of physical education, with lack of options and participation. In alignment with the civil educational approach, the research team aims to develop a predictive sport, movement, eating habits, relationships and technologies (S.M.A.R.T.) questionnaire to identify the youths that present a higher risk of delinquency. The following research aims to explore preliminary data from 501 adolescents completing the S.M.A.R.T. The results show that the female group (n = 260) was healthier than the male group (n = 241); particularly, the female group demonstrated a higher level of self-awareness in the use of technologies (p < 0.05). Our results produce the first data set on a cohort of young adolescents in Italy using the S.M.A.R.T. questionnaire. The questionnaire possesses a high response rate and should now be implemented towards validation.

The Adherence of Singaporean Students in Different Educational Institutions to National Food-Based Dietary Guidelines

There are currently limited data on the dietary habits of young Singaporeans. This study aimed to evaluate the adherence of 17–21 year olds attending different educational institutions using a novel diet-quality scoring method. Dietary data were collected using a single weekday 24 h dietary recall in a cross section of 536 Singaporeans aged 17–21 years. An 11 category scoring system (0.0–100.0) was used to define adherence to food based dietary guidelines. Demographic and self-reported data were also collected via a questionnaire, BMI status, and using Mann-Whitney and Kruskal-Wallis (non-parametric) tests, with post-hoc Bonferroni-corrected tests. The median diet quality score was 48.5 (IQR 40.5, 56.4) for this cohort, with component scores for “Total fruit”, “Whole fruit”, “Total vegetables”, “Dark green leafy & orange vegetables”, “Whole grains”, “Dairy products”, and “Sodium” frequently scoring the minimum value. Median diet quality scores were statistically different for groups by ethnic origin (p < 0.001) and by educational institution (p < 0.001). Intake of fruit, vegetables, and whole grains is minimal, while sodium intake is frequently too high in young Singaporeans. Differences across ethnic groups and types of educational institutions suggest the need for targeted interventions to improve dietary habits in this population.

Sex and region-specific effects of high fat diet on PNNs in obesity susceptible rats

Perineuronal nets (PNNs) are specialized extracellular matrix structures that primarily surround fast-spiking parvalbumin (PV)-containing interneurons within the PFC. They regulate PV neuron function and plasticity to maintain cortical excitatory/inhibitory balance. For example, reductions in PNN intensity are associated with reduced local inhibition and enhanced pyramidal neuron firing. We previously found that exposure to dietary high fat reduced PNN intensity within the PFC of male Sprague-Dawley (SD) rats. However, how high fat affects PNNs in the PFC of females or in obesity-vulnerable vs. -resistant models is unknown. Therefore, we gave male and female SD, selectively bred obesity-prone (OP), and obesity-resistant rats (OR) free access to standard lab chow or 60% high fat for 21 days. We then measured the number of PNN positive cells and PNN intensity (determined by Wisteria floribunda agglutinin [WFA] staining) as well as the number of PV positive neurons using immunohistochemistry. We found sex and region-specific effects of dietary high fat on PNN intensity, in the absence of robust changes in cell number. Effects were comparable in SD and OP but differed in OR rats. Specifically, high fat reduced PNN intensities in male SD and OP rats but increased PNN intensities in female SD and OP rats. In contrast, effects in ORs were opposite, with males showing increases in PNN intensity and females showing a reduction in intensity. Finally, these effects were also region specific, with diet-induced reductions in PNN intensity found in the prelimbic PFC (PL-PFC) and ventral medial orbital frontal cortex (vmOFC) of SD and OP males in the absence of changes in the infralimbic PFC (IL-PFC), and increases in PNN intensity in the IL-PFC of SD and OP females in the absence of changes in other regions. These results are discussed in light of roles PNNs may play in influencing PFC neuronal activity and the differential role of these sub-regions in food-seeking and motivation.

Childhood and Adolescent Obesity: A Review

Obesity is a complex condition that interweaves biological, developmental, environmental, behavioral, and genetic factors; it is a significant public health problem. The most common cause of obesity throughout childhood and adolescence is an inequity in energy balance; that is, excess caloric intake without appropriate caloric expenditure. Adiposity rebound (AR) in early childhood is a risk factor for obesity in adolescence and adulthood. The increasing prevalence of childhood and adolescent obesity is associated with a rise in comorbidities previously identified in the adult population, such as Type 2 Diabetes Mellitus, Hypertension, Non-alcoholic Fatty Liver disease (NAFLD), Obstructive Sleep Apnea (OSA), and Dyslipidemia. Due to the lack of a single treatment option to address obesity, clinicians have generally relied on counseling dietary changes and exercise. Due to psychosocial issues that may accompany adolescence regarding body habitus, this approach can have negative results. Teens can develop unhealthy eating habits that result in Bulimia Nervosa (BN), Binge- Eating Disorder (BED), or Night eating syndrome (NES). Others can develop Anorexia Nervosa (AN) as they attempt to restrict their diet and overshoot their goal of "being healthy." To date, lifestyle interventions have shown only modest effects on weight loss. Emerging findings from basic science as well as interventional drug trials utilizing GLP-1 agonists have demonstrated success in effective weight loss in obese adults, adolescents, and pediatric patients. However, there is limited data on the efficacy and safety of other weight-loss medications in children and adolescents. Nearly 6% of adolescents in the United States are severely obese and bariatric surgery as a treatment consideration will be discussed. In summary, this paper will overview the pathophysiology, clinical, and psychological implications, and treatment options available for obese pediatric and adolescent patients.