A four-day Western-style dietary intervention causes reductions in hippocampal-dependent learning and memory and interoceptive sensitivity

From Obesity to Hippocampal Neurodegeneration: Pathogenesis and Non-Pharmacological Interventions

High-caloric diet and physical inactivity predispose individuals to obesity and diabetes, which are risk factors of hippocampal neurodegeneration and cognitive deficits. Along with the adipose-hippocampus crosstalk, chronically inflamed adipose tissue secretes inflammatory cytokine could trigger neuroinflammatory responses in the hippocampus, and in turn, impairs hippocampal neuroplasticity under obese and diabetic conditions. Hence, caloric restriction and physical exercise are critical non-pharmacological interventions to halt the pathogenesis from obesity to hippocampal neurodegeneration. In response to physical exercise, peripheral organs, including the adipose tissue, skeletal muscles, and liver, can secret numerous exerkines, which bring beneficial effects to metabolic and brain health. In this review, we summarized how chronic inflammation in adipose tissue could trigger neuroinflammation and hippocampal impairment, which potentially contribute to cognitive deficits in obese and diabetic conditions. We also discussed the potential mechanisms underlying the neurotrophic and neuroprotective effects of caloric restriction and physical exercise by counteracting neuroinflammation, plasticity deficits, and cognitive impairments. This review provides timely insights into how chronic metabolic disorders, like obesity, could impair brain health and cognitive functions in later life.

Role of Neuroendocrine, Immune, and Autonomic Nervous System in Anorexia Nervosa-Linked Cardiovascular Diseases

Anorexia nervosa represents a severe mental disorder associated with food avoidance and malnutrition. In patients suffering from anorexia nervosa, cardiovascular complications are the main reason leading to morbidity and mortality. However, the origin and pathological mechanisms leading to higher cardiovascular risk in anorexia nervosa are still unclear. In this aspect, the issue of exact pathological mechanisms as well as sensitive biomarkers for detection of anorexia nervosa-linked cardiovascular risk are discussed. Therefore, this review synthesised recent evidence of dysfunction in multiple neuroendocrine axes and alterations in the immune system that may represent anorexia nervosa-linked pathological mechanisms contributing to complex cardiovascular dysregulation. Further, this review is focused on identification of non-invasive biomarkers for the assessment of increased cardiovascular risk in anorexia nervosa that can be linked to a clinical application. Complex non-invasive assessment of cardiovascular autonomic regulation—cardiac vagal control (heart rate variability), sympathetic vascular activity (blood pressure variability), and cardiovascular reflex control (baroreflex sensitivity)—could represent a promising tool for early diagnosis, personalized therapy, and monitoring of therapeutic interventions in anorexia nervosa particularly at a vulnerable adolescent age.

The impact of hippocampal damage on appetitive control

Animal data indicates the hippocampus assists appetite-regulation.  We tested this in humans, contrasting two patients (DW, JC) with hippocampal damage to controls on an appetite-regulation test conducted hungry and sated.  When hungry, controlsviewed palatable snacks and reported a desire to eat them, a memory-based judgment.  After sampling them, they reported liking their taste.  Post-lunch (DW ate little, precluding a test of our hypothesis), controls showed a large decrease in desire for the snacks, but less change in taste-liking.  JC ate like controls, but reported no change in desire across states, suggesting that the human hippocampus also contributes to appetite-regulation.

Interoception and Its Role for Eating, Obesity, and Eating Disorders

Abstract. The importance of the sense of ourselves from within for understanding adaptive behavior and psychopathology has been increasingly recognized during the last decades. Interoception builds the foundation of our embodied self and dysfunctional interoception lies at the core of many psychosomatic disorders. Eating is fundamental for survival with consequences for health and well-being. It is deeply grounded in homoeostatic and allostatic psychophysiological needs and is driven by interoceptive signals of the body. This narrative review summarizes a selection of empirical findings and draws conclusions on the role of interoception in eating behavior, body weight, and eating disorders. Beyond disordered eating behavior, eating disorders are characterized by impairment of the sense of self, with dysfunctional interoception at its core. Predictive coding accounts are addressed to integrate conclusions and to underline the relevance of interventions to modify interoception.

Cerebral Fructose Metabolism as a Potential Mechanism Driving Alzheimer's Disease

The loss of cognitive function in Alzheimer's disease is pathologically linked with neurofibrillary tangles, amyloid deposition, and loss of neuronal communication. Cerebral insulin resistance and mitochondrial dysfunction have emerged as important contributors to pathogenesis supporting our hypothesis that cerebral fructose metabolism is a key initiating pathway for Alzheimer's disease. Fructose is unique among nutrients because it activates a survival pathway to protect animals from starvation by lowering energy in cells in association with adenosine monophosphate degradation to uric acid. The fall in energy from fructose metabolism stimulates foraging and food intake while reducing energy and oxygen needs by decreasing mitochondrial function, stimulating glycolysis, and inducing insulin resistance. When fructose metabolism is overactivated systemically, such as from excessive fructose intake, this can lead to obesity and diabetes. Herein, we present evidence that Alzheimer's disease may be driven by overactivation of cerebral fructose metabolism, in which the source of fructose is largely from endogenous production in the brain. Thus, the reduction in mitochondrial energy production is hampered by neuronal glycolysis that is inadequate, resulting in progressive loss of cerebral energy levels required for neurons to remain functional and viable. In essence, we propose that Alzheimer's disease is a modern disease driven by changes in dietary lifestyle in which fructose can disrupt cerebral metabolism and neuronal function. Inhibition of intracerebral fructose metabolism could provide a novel way to prevent and treat this disease.

Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment

Poor diet and obesity are associated with cognitive impairment throughout adulthood, and increased dementia risk in aging. Here we review the current literature interrogating the mechanisms by which diets high in fat, or fat and sugar lead to cognitive impairment, focusing on changes to gut microbiome composition, inflammatory signalling and blood-brain barrier integrity. Preclinical studies indicate weight gain is not necessary for diet-induced cognitive impairment. Rather, gut microbiome composition, and systemic and central inflammatory processes appear to contribute to diet-induced cognitive impairment. While both obese humans and rodents exhibit reduced blood-brain barrier integrity, cognitive impairments precede these changes, suggesting other mechanisms may underly diet-induced cognitive changes. Other potential candidates include hormone, glucoregulatory and cardiovascular changes. Poor diet and obesity act through multiple mechanisms to affect cognitive health and the challenge for future research is to identify key processes that can be reversed to improve cognition and quality of life.

Interaction Between Circadian Rhythms, Energy Metabolism, and Cognitive Function

The interaction between meal timing and light regulates circadian rhythms in mammals and not only determines the sleep-wake pattern but also the activity of the endocrine system. Related with that, the necessity to fulfill energy needs is a driving force that requires the participation of cognitive skills whose performance has been shown to undergo circadian variations. These facts have led to the concept that cognition and feeding behaviour can be analysed from a chronobiological perspective. In this context, research carried out during the last two decades has evidenced the link between feeding behaviour/nutritional habits and cognitive processes, and has highlighted the impact of circadian disorders on cognitive decline. All that has allowed hypothesizing a tight relationship between nutritional factors, chronobiology, and cognition. In this connection, experimental diets containing elevated amounts of fat and sugar (high-fat diets; HFDs) have been shown to alter in rodents the circadian distribution of meals, and to have a negative impact on cognition and motivational aspects of behaviour that disappear when animals are forced to adhere to a standard temporal eating pattern. In this review, we will present relevant studies focussing on the effect of HFDs on cognitive aspects of behaviour, paying particular attention to the influence that chronobiological alterations caused by these diets may have on hippocampaldependent cognition.

Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet

Animals fed a Western-style diet (WS-diet) demonstrate rapid impairments in hippocampal function and poorer appetitive control. We examined if this also occurs in humans. One-hundred and ten healthy lean adults were randomized to either a one-week WS-diet intervention or a habitual-diet control group. Measures of hippocampal-dependent learning and memory (HDLM) and of appetitive control were obtained pre- and post-intervention. HDLM was retested at three-week follow-up. Relative to controls, HDLM performance declined in the WS-diet group (d = 0.43), but was not different at follow-up. Appetitive control also declined in the WS-diet group (d = 0.47) and this was strongly correlated with HDLM decline (d = 1.01). These findings demonstrate that a WS-diet can rapidly impair appetitive control in humans-an effect that could promote overeating in consumers of a WS-diet. The study also suggests a functional role for the hippocampus in appetitive control and provides new evidence for the adverse neurocognitive effects of a WS-diet.

A Preliminary Investigation of the Effects of a Western Diet on Hippocampal Volume in Children

Introduction: Over the course of the 20th century, there has been a sharp increase in the consumption of saturated fat and refined sugars. This so-called "western diet" (WD) has been extensively linked to biological alterations and associated functional deficits in the hippocampus of animals. However, the effects of a WD on the human hippocampus are less well-characterized. This preliminary study aimed to extend prior animal work by investigating the effects of a WD on hippocampal volume in children. Methods: Twenty-one healthy children (ages 5-9) completed a structural T1-weighted magnetic resonance imaging scan. Bilateral hippocampal volumes (as regions-of-interest) and bilateral amygdala volumes (as medial temporal lobe control regions-of-interest) were calculated. WD variables were derived from the parent-completed Youth/Adolescent Food Frequency Questionnaire. Specifically, variables were calculated as percent of daily calories consumed from sugars, fats, or a combination of these (WD). Results: While the relationships between overall WD consumption and bilateral hippocampal volumes were not significant, increased fat consumption was significantly related to decreased left hippocampal volume. Sugar consumption was not related to hippocampal size. Control region volumes were not related to any diet variables. Discussion: This study is the first to directly link diet-specifically fat consumption-to decreased left hippocampal volume in children. This extends previous work showing smaller left hippocampal volume related to obesity in pediatric samples. Though preliminary, findings represent an important step toward understanding the impact of diet on child brain development.

A Brief Neuropsychological Battery for Measuring Cognitive Functions Associated with Obesity

OBJECTIVE

Although ample evidence links obesity to cognitive dysfunction, the trajectory of cognitive change, the underlying mechanisms, and the involvement of related factors, such as metabolic disease and diet, remain unclear. To support further investigations of BMI and cognition, this study aimed to create a concise test battery to be used in future trials.

METHODS

Twenty neurocognitive measures were regressed on BMI in the Human Connectome Project Healthy Young Adult S1200 data release by using linear mixed models and by adjusting for major confounders. Measures were then identified by using least absolute shrinkage and selection operator regression analysis to select tests most strongly associated with BMI. To guide further test selection, the explained variance for each variable was visualized in the final model.

RESULTS

BMI was negatively associated with seven neurocognitive measures. Variable selection yielded a model that included years of education and, in order of model weight, delay discounting, the relational task, the Penn Progressive Matrices test, the oral reading recognition test, the Variable Short Penn Line Orientation test, and the Penn Word Memory test.

CONCLUSIONS

This research resulted in an approximate 40-minute test battery for the BMI-cognition relationship in young adults that can be used in trials investigating the interrelationship between obesity and cognitive performance.

Nutritional psychiatry: Towards improving mental health by what you eat

Does it matter what we eat for our mental health? Accumulating data suggests that this may indeed be the case and that diet and nutrition are not only critical for human physiology and body composition, but also have significant effects on mood and mental wellbeing. While the determining factors of mental health are complex, increasing evidence indicates a strong association between a poor diet and the exacerbation of mood disorders, including anxiety and depression, as well as other neuropsychiatric conditions. There are common beliefs about the health effects of certain foods that are not supported by solid evidence and the scientific evidence demonstrating the unequivocal link between nutrition and mental health is only beginning to emerge. Current epidemiological data on nutrition and mental health do not provide information about causality or underlying mechanisms. Future studies should focus on elucidating mechanism. Randomized controlled trials should be of high quality, adequately powered and geared towards the advancement of knowledge from population-based observations towards personalized nutrition. Here, we provide an overview of the emerging field of nutritional psychiatry, exploring the scientific evidence exemplifying the importance of a well-balanced diet for mental health. We conclude that an experimental medicine approach and a mechanistic understanding is required to provide solid evidence on which future policies on diet and nutrition for mental health can be based.

Pattern of access to cafeteria-style diet determines fat mass and degree of spatial memory impairments in rats

Repeated ‘cycling’ between healthy and unhealthy eating is increasingly common but the effects of such cycling on cognitive function are unknown. Here we tested the effects of cycling between chow and a cafeteria diet (CAF) rich in saturated fat and refined carbohydrates on fat mass and place recognition memory in rats. Rats fed the chow diet (control group) were compared with groups fed CAF for either: 3 consecutive days per week followed by 4 days of chow, (3CAF:4CHOW group); 5 consecutive days per week followed by 2 days of chow (5CAF:2CHOW group); or 7 days per week (7CAF group). Total days of exposure to CAF were matched between the latter groups by staggering the introduction of CAF diet. After 16–18 days of CAF, spatial recognition memory was significantly worse in the 7CAF group relative to controls. After 23–25 days of CAF, both the 7CAF and 5CAF:2CHOW groups, but not the 3CAF:4CHOW group, were impaired relative to controls, mirroring changes in fat mass measured by EchoMRI. CAF feeding did not affect object recognition memory or total exploration time. These results indicate that even when matching total exposure, the pattern of access to unhealthy diets impairs spatial memory in a graded fashion.

Can krill oil be of use for counteracting neuroinflammatory processes induced by high fat diet and aging?

Most neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, demonstrate preceding or on-going inflammatory processes. Therefore, discovering effective means of counteracting detrimental inflammatory mediators in the brain could help alter aging-related disease onset and progression. Fish oil and marine-derived omega-3, long-chain polyunsaturated fatty acids (LC n-3) have shown promising anti-inflammatory effects both systemically and centrally. More specifically, krill oil (KO), extracted from small Antarctic crustaceans, is an alternative type of LC n-3 with reported health benefits including improvement of spatial memory and learning, memory loss, systemic inflammation and depression symptoms. Similar to the more widely studied fish oil, KO contains the long chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which are essential for basic brain functions. Moreover, the phospholipid bound nature of fatty acids found in KO improves bioavailability and efficiency of absorption, thus supporting the belief that KO may offer a superior method of dietary n-3 delivery. Finally, KO contains astaxanthin, an antioxidant capable of reducing potentially excessive oxidative stress and inflammation within the brain. This review will discuss the potential benefits of KO over other marine-based LC n-3 on brain inflammation and cognitive function in the context of high fat diets and aging.

Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?

As the influence of diet on health may take place over a period of decades, there is a need for biomarkers that help to identify those aspects of nutrition that have either a positive or a negative influence. The evidence is considered that heart-rate variability (HRV) (the time differences between one beat and the next) can be used to indicate the potential health benefits of food items. Reduced HRV is associated with the development of numerous conditions for example, diabetes, cardiovascular disease, inflammation, obesity and psychiatric disorders. Although more systematic research is required, various aspects of diet have been shown to benefit HRV acutely and in the longer term. Examples include a Mediterranean diet, omega-3 fatty acids, B-vitamins, probiotics, polyphenols and weight loss. Aspects of diet that are viewed as undesirable, for example high intakes of saturated or trans-fat and high glycaemic carbohydrates, have been found to reduce HRV. It is argued that the consistent relationship between HRV, health and morbidity supports the view that HRV has the potential to become a widely used biomarker when considering the influence of diet on mental and physical health.

The Cognitive Control of Eating and Body Weight: It's More Than What You "Think"

Over the past decade, a great deal of research has established the importance of cognitive processes in the control of energy intake and body weight. The present paper begins by identifying several of these cognitive processes. We then summarize evidence from human and nonhuman animal models, which shows how excess intake of obesity-promoting Western diet (WD) may have deleterious effects on these cognitive control processes. Findings that these effects may be manifested as early-life deficits in cognitive functioning and may also be associated with the emergence of serious late-life cognitive impairment are described. Consistent with these possibilities, we review evidence, obtained primarily from rodent models, that consuming a WD is associated with the emergence of pathophysiologies in the hippocampus, an important brain substrate for learning, memory, and cognition. The implications of this research for mechanism are discussed within the context of a “vicious-cycle model,” which describes how eating a WD could impair hippocampal function, producing cognitive deficits that promote increased WD intake and body weight gain, which could contribute to further hippocampal dysfunction, cognitive decline, and excess eating and weight gain.

Influence of High-Fat Diets Consumed During the Juvenile Period on Hippocampal Morphology and Function

The negative impact of obesity on neurocognitive functioning is an issue of increasing clinical interest. Over the last decade, a number of studies have analyzed the influence of high-fat diets (HFDs) on cognitive performance, particularly in adolescent individuals. Different approaches, including behavioral, neurochemical, electrophysiological and morphological studies, have been developed to address the effect of HFDs on neural processes interfering with learning and memory skills in rodents. Many of the studies have focused on learning and memory related to the hippocampus and the mechanisms underlying these processes. The goal of the current review article is to highlight the relationship between hippocampal learning/memory deficits and nutritional/endocrine inputs derived from HFDs consumption, with a special emphasis on research showing the effect of HFDs intake during the juvenile period. We have also reviewed recent research regarding the effect of HFDs on hippocampal neurotransmission. An overview of research suggesting the involvement of fatty acid (FA) receptor-mediated signaling pathways in memory deficits triggered by HFDs is also provided. Finally, the role of leptin and HFD-evoked hyperleptinemia is discussed.

Carbohydrates and cognitive function

PURPOSE OF REVIEW

Recent evidence documents the negative impact of obesity, diabetes mellitus, and other metabolic dysregulation on neurocognitive function. This review highlights a key dietary factor in these relationships: refined carbohydrates.

RECENT FINDINGS

Chronic consumption of refined carbohydrates has been linked to relative neurocognitive deficits across the lifespan. Hippocampal function is especially impacted, but prefrontal and mesolimbic reward pathways may also be altered. Early life exposure to refined carbohydrates, (i.e., prenatal, juvenile, and adolescence periods) may be particularly toxic to cognitive functioning. The impact of acute carbohydrate administration is mixed, with some findings showing benefits while others are neutral or negative. Potential mechanisms of the carbohydrate-cognition relationship include dysregulation in metabolic, inflammatory, and vascular factors, whereas moderators include age, genetic factors, physiological (e.g., glucoregulatory) function and the timing and type of carbohydrate exposure. Critically, the negative neurocognitive impacts of diets high in refined carbohydrates have been shown to be independent of total body weight.

SUMMARY

Neurocognitive deficits induced by a diet high in refined carbohydrates may manifest before overt obesity or metabolic disease onset, suggesting that researchers and providers may need to target subclinical metabolic, inflammatory, and vascular dysregulation factors in efforts to preserve cognitive function across the lifespan.

Cocaine impairs serial-feature negative learning and blood-brain barrier integrity

Previous research has shown that diets high in fat and sugar [a.k.a., Western diets (WD)] can impair performance of rats on hippocampal-dependent learning and memory problems, an effect that is accompanied by selective increases in hippocampal blood brain barrier (BBB) permeability. Based on these types of findings, it has been proposed that overeating of a WD (and its resulting obesity) may be, in part, a consequence of impairments in these anatomical substrates and cognitive processes. Given that drug use (and addiction) represents another behavioral excess, the present experiments assessed if similar outcomes might occur with drug exposure by evaluating the effects of cocaine administration on hippocampal-dependent memory and on the integrity of the BBB. Experiment 1 of the present series of studies found that systemic cocaine administration in rats also appears to have disruptive effects on the same hippocampal-dependent learning and memory mechanism that has been proposed to underlie the inhibition of food intake. Experiment 2 demonstrated that the same regimen of cocaine exposure that produced disruptions in learning and memory in Experiment 1 also produced increased BBB permeability in the hippocampus, but not in the striatum. Although the predominant focus of previous research investigating the etiologies of substance use and abuse has been on the brain circuits that underlie the motivational properties of drugs, the current investigation implicates the possible involvement of hippocampal memory systems in such behaviors. It is important to note that these positions are not mutually exclusive and that neuroadaptations in these two circuits might occur in parallel that generate dysregulated drug use in a manner similar to that of excessive eating.

A mind cleared by walnut oil: The effects of polyunsaturated and saturated fat on extinction learning

The treatment of anxiety-based psychopathology often hinges upon extinction learning. Research in nutritional neuroscience has observed that the regular consumption of perilla oil (50% alpha-linolenic acid (ALA)) facilitates extinction learning in rats (Yamamoto et al., 1988). However, acute facilitation of extinction learning by oils rich in ALA has not been reported for rats or humans, though the acute consumption of rapeseed oil (10% ALA) has been observed to improve cognitive processing speed in humans (Jones, Sünram-Lea, & Wesnes, 2012). For this reason, the present laboratory work examined the effects of adding walnut oil (12% ALA) to a chocolate milkshake on the acquisition, generalization, and extinction of a fear-based prediction in young adults. It compared performance between subjects. The other participants consumed a similar milkshake with either an equicaloric amount of cream (saturated fat), or with no added fat (control). Acquisition and generalization of the fear-based prediction were similar for all groups. However, those who consumed walnut oil extinguished most rapidly and profoundly. Implications for extinction learning are discussed.

Cognitive Control of Eating: the Role of Memory in Appetite and Weight Gain

PURPOSE OF REVIEW

The present review organises the recent literature on the role of memory in eating behaviours and provides an overview of the current evidence relating to the associations between memory and weight gain.

RECENT FINDINGS

Research over the last few years has highlighted working memory as an important cognitive process that underpins many aspects of appetite control. Recent work on episodic memory and appetite has replicated work showing that manipulating memory for recent eating affects later consumption and extended this work to examine associations between individual differences in memory and eating behaviours. Poorer episodic memory ability is related to a reduced sensitivity to internal states of hunger and satiety and a tendency towards uncontrolled eating. There is also recent evidence to suggest that working memory and episodic memory impairments are related to weight gain and high BMI. Working memory and episodic memory are core cognitive processes that are critical for food-related decision-making, and disruption to these processes contributes to problems with appetite control and weight gain, which suggests that weight loss programmes might be improved by the addition of cognitive training.

Dietary influences on cognition

Obesity is a world-wide crisis with profound healthcare and socio-economic implications and it is now clear that the central nervous system (CNS) is a target for the complications of metabolic disorders like obesity. In addition to decreases in physical activity and sedentary lifestyles, diet is proposed to be an important contributor to the etiology and progression of obesity. Unfortunately, there are gaps in our knowledge base related to how dietary choices impact the structural and functional integrity of the CNS. For example, while chronic consumption of hypercaloric diets (increased sugars and fat) contribute to increases in body weight and adiposity characteristic of metabolic disorders, the mechanistic basis for neurocognitive deficits in obesity remains to be determined. In addition, studies indicate that acute consumption of hypercaloric diets impairs performance in a wide variety of cognitive domains, even in normal non-obese control subjects. These results from the clinical and basic science literature indicate that diet can have rapid, as well as long lasting effects on cognitive function. This review summarizes our symposium at the 2017 Society for the Study of Ingestive Behavior (SSIB) meeting that discussed these effects of diet on cognition. Collectively, this review highlights the need for integrated and comprehensive approaches to more fully determine how diet impacts behavior and cognition under physiological conditions and in metabolic disorders like type 2 diabetes mellitus (T2DM) and obesity.

Snacking Quality Is Associated with Secondary School Academic Achievement and the Intention to Enroll in Higher Education: A Cross-Sectional Study in Adolescents from Santiago, Chile

Although numerous studies have approached the effects of exposure to a Western diet (WD) on academic outcomes, very few have focused on foods consumed during snack times. We explored whether there is a link between nutritious snacking habits and academic achievement in high school (HS) students from Santiago, Chile. We conducted a cross-sectional study with 678 adolescents. The nutritional quality of snacks consumed by 16-year-old was assessed using a validated food frequency questionnaire. The academic outcomes measured were HS grade point average (GPA), the likelihood of HS completion, and the likelihood of taking college entrance exams. A multivariate analysis was performed to determine the independent associations of nutritious snacking with having completed HS and having taken college entrance exams. An analysis of covariance (ANCOVA) estimated the differences in GPA by the quality of snacks. Compared to students with healthy in-home snacking behaviors, adolescents having unhealthy in-home snacks had significantly lower GPAs (M difference: -40.1 points, 95% confidence interval (CI): -59.2, -16.9, d = 0.41), significantly lower odds of HS completion (adjusted odds ratio (aOR): 0.47; 95% CI: 0.25-0.88), and significantly lower odds of taking college entrance exams (aOR: 0.53; 95% CI: 0.31-0.88). Unhealthy at-school snacking showed similar associations with the outcome variables. Poor nutritional quality snacking at school and at home was associated with poor secondary school academic achievement and the intention to enroll in higher education.