Variety, palatability, and obesity

Cannabidiol improves maternal obesity-induced behavioral, neuroinflammatory and neurochemical dysfunctions in the juvenile offspring

Maternal obesity is associated with an increased risk of psychiatric disorders such as anxiety, depression, schizophrenia and autism spectrum disorder in the offspring. While numerous studies focus on preventive measures targeting the mothers, only a limited number provide practical approaches for addressing the damages once they are already established. We have recently demonstrated the interplay between maternal obesity and treatment with cannabidiol (CBD) on hypothalamic inflammation and metabolic disturbances, however, little is known about this relationship on behavioral manifestations and neurochemical imbalances in other brain regions. Therefore, here we tested whether CBD treatment could mitigate anxiety-like and social behavioral alterations, as well as neurochemical disruptions in both male and female offspring of obese dams. Female Wistar rats were fed a cafeteria diet for 12 weeks prior to mating, and during gestation and lactation. Offspring received CBD (50 mg/kg) from weaning for 3 weeks. Behavioral tests assessed anxiety-like manifestations and social behavior, while neuroinflammatory and neurochemical markers were evaluated in the prefrontal cortex (PFC) and hippocampus. CBD treatment attenuated maternal obesity-induced anxiety-like and social behavioral alterations, followed by rescuing effects on imbalanced neurotransmitter and endocannabinoid concentrations and altered expression of glial markers, CB1, oxytocin and dopamine receptors, with important differences between sexes. Overall, the findings of this study provide insight into the signaling pathways for the therapeutic benefits of CBD on neuroinflammation and neurochemical imbalances caused by perinatal maternal obesity in the PFC and the hippocampus, which translates into the behavioral manifestations, highlighting the sexual dimorphism encompassing both the transgenerational effect of obesity and the endocannabinoid system.

Uncontrolled eating is associated with higher impulsiveness, risk taking and novelty-seeking

Previous studies suggest that trait disinhibition as measured by the Three Factor eating Questionnaire (TFEQ) is related to selected measures of impulsivity and risk taking. However, the factor validity of the original trait disinhibition measure has been questioned, and a revised scale of uncontrolled eating consequently developed. To date few studies have revisited the relationship between impulsivity and the uncontrolled and emotional eating scales of the revised TFEQ. In the present study, 283 participants (208 women) completed the revised TFEQ alongside a battery of measures of impulsivity and risk taking in an online study. The total and all subscale scores on the Barratt Impulsiveness Scale were significantly associated with scores on the uncontrolled, but not emotional or restrained, TFEQ scale. Likewise, risky behaviour indexed by the average number of pumps per trial on the Balloon Analogue Risk Task were also associated with uncontrolled, but not emotional or restrained, eating, and the same pattern of associations were also found for the novelty, but not intensity, subscales of the Arnetts Inventory of Sensation Seeking. Overall these data suggest that uncontrolled eating is related to wider personality traits of risky decision making, novelty seeking and wider cognitive impulsivity, which may in turn increase of future weight gain.

Food insecurity is associated with low diet quality and unhealthy cooking and eating habits in Iranian women

BACKGROUND

Food insecurity affects diet and nutrition intakes. We explored the relationship between food insecurity and dietary intakes in a group of Iranian women.

METHODS

The cross-sectional study was performed on 190 healthy females aged 20-55 years attending primary healthcare centers in Shiraz. Food insecurity was evaluated by Household Food Insecurity Access Scale, which is a validated tool for assessing food insecurity in developing countries. Diet was assessed using a food frequency questionnaire. The association of dietary patterns and food insecurity was assessed by linear regression.

RESULTS

Assessment of dietary intakes revealed that consumption of red meat, poultry, fish, dairy, fruits, non-starchy vegetables, and nuts decreased whereas that of grains, processed meats, potato, and sugary foods increased with increasing food insecurity. Among nutrients, carbohydrates, fiber, vitamin A, vitamin C, folic acid, potassium, calcium, and magnesium decreased while fat and sodium increased as food insecurity increased. Three major dietary patterns were detected. Healthy dietary patterns showed inverse associations with food insecurity in the crude (β = -0.422 and - 0.435, P < 0.001) and adjusted (adjusted for age, marital status, and educational level) (β = -0.475 and - 0.341, P < 0.001) models of regression analysis but unhealthy pattern did not show an association with food insecurity. Compared to food secure participants, a higher percentage of food insecure individuals indicated unhealthy eating habits, such as skipping breakfast, lower snack ingestion, more fast and fried food consumption, and using unhealthy cooking methods.

CONCLUSION

Overall, this study showed that food insecurity was associated with less healthy diet and unhealthy cooking and eating habits.

Mindfulness, mental health, and motives for eating tasty foods when not in metabolic need

Habitual consumption of highly palatable foods when not in metabolic need (HPF eating) is linked to obesity. High HPF consumption is also linked to mental health disorder (MHD) symptoms. Mindfulness-based interventions are popular treatments for obesity and MHDs, but little is known about the relationship between trait mindfulness and motive-based HPF eating. Therefore, a total of 927 young adults completed a survey that included the Palatable Eating Motives Scale-7 (which identifies Coping-, Reward enhancement-, Social-, and Conformity-eating), the Mindful Attention Awareness Scale, the Perceived Stress Scale, and demographic and body mass index (BMI) questions. An MHD questionnaire allowed a comparison of HPF eating between participants with and without various MHDs. Regressions revealed that Coping-eating was independently associated with lower mindfulness and also greater perceived stress, higher BMI, and female sex. Of these variables, only lower mindfulness was independently associated with Reward-, Social-, and Conformity-eating. Coping- and Reward-eating were more frequent in participants with versus without an anxiety disorder, depression, ADD/ADHD, and PTSD. Coping-eating was also more frequent in participants with body dysmorphic disorder. These findings warrant investigations in participants with clinically validated diagnoses for DSM-specific MHDs. Results from such investigations and the uncovered nature of associations between motive-specific HPF eating and trait mindfulness could provide novel targets to improve mindfulness-based interventions for obesity and MHDs.

Motives and food craving: Associations with frequency of hyper-palatable food intake among college students

BACKGROUND

College food environments provide wide access to hyper-palatable foods (HPF). Palatable eating motives and craving are individual factors that may impact HPF intake. Nevertheless, no study to date has examined the relationship between these factors and frequency of HPF intake in a dormitory all-you-can-eat-style cafeteria meal, a typical college food setting.

METHODS

College students (N = 218) self-reported frequency of HPF intake at a college cafeteria meal and their frequency of HPF intake in the overall diet. Quasipoisson and logistic regression models tested whether palatable eating motives (assessed via the Palatable Eating Motives Scale) and craving (assessed via the Food Craving Inventory) were associated with the rate of HPF intake during the cafeteria meal and excess frequency of HPF intake in the overall diet.

RESULTS

Craving was associated with a 19% higher rate of HPF intake during the cafeteria meal (RR = 1.19; p = .015) and a >2-fold higher likelihood of excess frequency of HPF intake the overall diet (OR = 2.69; p < .001). Coping motive was associated with an 87% higher likelihood of excess frequency of HPF intake in the overall diet (OR = 1.87; p = .002), but not in the cafeteria meal. Reward enhancement, social and conformity motives were not significantly associated with the frequency of HPF intake in either setting.

CONCLUSIONS

Results highlight the role of craving and coping motive in the frequency of HPF intake among college students. Prevention efforts may consider targeting craving and eating to cope to potentially address frequency of HPF intake among college students.

Variety and portion size combine to increase food intake at single-course and multi-course meals

Increases in food variety and portion size independently promote intake. Little is known about how these effects combine or how they depend on meal structure. In two randomized crossover experiments, once a week for four weeks, women ate a lunch meal that was varied in two properties: variety (low: three bowls of the favorite dish vs. high: three bowls, each with a different main dish) and portion size (small: 450 g vs. large: 600 g). In Experiment 1 (n = 42), dishes were served simultaneously and in Experiment 2 (n = 49), dishes were served sequentially over three courses. At each meal, the primary outcome of food intake was measured; additionally, we measured sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten). In Experiment 1 (simultaneous structure) variety and portion size did not interact (p = 0.72) but both independently increased intake; participants consumed 15 ± 7 g more at meals with high variety compared to low and 57 ± 7 g more from large portions compared to small (both p < 0.03). Similarly, in Experiment 2 (sequential structure) variety and portion size did not interact (p = 0.99) but participants consumed 30 ± 8 g more at high-variety meals and 51 ± 8 g more from large portions (both p < 0.001). SSS was not influenced by portion size in either experiment (both p > 0.16) or by variety in Experiment 1 (p = 0.58), but SSS was smaller at high-variety meals in Experiment 2 (p = 0.001). Thus, variety and large portions promoted greater food intake for a similar or smaller hedonic decline, indicating these effects were facilitated by delayed SSS. At meals with either a simultaneous or sequential structure, high variety and large portions combined to increase intake, suggesting that these common properties act together to promote overconsumption.

Food addiction as a mediator between depressive symptom severity and body mass index

Depression is associated with an increased risk of cardiometabolic disease linked to weight gain driven by complex interactions between multiple risk factors, including overeating behaviours. However, risk factors that mediate the relationship between depressive symptoms and weight gain remain to be fully elucidated. This study examined food addiction symptoms as a potential mediator on the relationship between depressive symptom severity and adiposity as measured by body mass index (BMI), and evaluated whether this relationship was contingent on appetite symptom profile and sex. In a sample of 628 adults, depressive symptom severity was assessed using the Centre for Epidemiological Studies Depression Scale (CES-D), and food addiction symptoms were measured using the Yale Food Addiction Scale (YFAS, version 2). Participant demographics, including BMI, appetite presentations and sex, were assessed using self-report questions. Mediation and moderated mediation analyses were performed to determine relationships between variables. The prevalence of depressogenic food addiction in the present sample was 21.7%. After accounting for age and averaged amount of exercise, food addiction symptoms fully mediated the relationship between depressive symptom severity and BMI. Appetite symptom profile was a significant moderator of this relationship, with effects more pronounced in those with increased appetite compared to decreased or unchanged appetite. While sex was not a significant moderator, being male or female was associated with higher food addiction scores. This study supports food addiction symptoms as an important behavioural risk factor for increased adiposity linked to greater depressive symptom severity, particularly in those experiencing increased appetite during a depressive episode. Assessment and monitoring of food addiction symptoms may have utility in reducing the risk of increased BMI and adverse health outcomes in those experiencing more severe depressive symptoms.

Slc12a2 loss in insulin-secreting β-cells links development of overweight and metabolic dysregulation to impaired satiation control of feeding

Male mice lacking the Na+-K+-2Cl- cotransporter Slc12a2 (Nkcc1) specifically in insulin-secreting β-cells (Slc12a2βKO) have reduced β-cell mass and mild β-cell secretory dysfunction associated with overweight, glucose intolerance, insulin resistance, and metabolic abnormalities. Here, we confirmed and extended previous results to female Slc12a2βKO mice, which developed a similar metabolic syndrome-like phenotype as males, albeit milder. Notably, male and female Slc12a2βKO mice developed overweight without consuming excess calories. Analysis of the feeding microstructure revealed that young lean Slc12a2βKO male mice ate meals of higher caloric content and at a relatively lower frequency than normal mice, particularly during the night. In addition, overweight Slc12a2βKO mice consumed significantly larger meals than lean mice. Therefore, the reduced satiation control of feeding precedes the onset of overweight and is worsened in older Slc12a2βKO mice. However, the time spent between meals remained intact in lean and overweight Slc12a2βKO mice, indicating conserved satiety responses to ad libitum feeding. Nevertheless, satiety was intensified during and after refeeding only in overweight males. In lean females, satiety responses to refeeding were delayed relative to age- and body weight-matched control mice but normalized in overweight mice. Since meal size did not change during refeeding, these data suggested that the satiety control of eating after fasting is impaired in lean Slc12a2βKO mice before the onset of overweight and independently of their reduced satiation responses. Therefore, our results support the novel hypothesis that reduced satiation precedes the onset of overweight and the development of metabolic dysregulation.NEW & NOTEWORTHY Obesity, defined as excess fat accumulation, increases the absolute risk for metabolic diseases. Although obesity is usually attributed to increased food intake, we demonstrate that body weight gain can be hastened without consuming excess calories. In fact, impaired meal termination control, i.e., satiation, is detectable before the development of overweight in an animal model that develops a metabolic syndrome-like phenotype.

Associations between dietary variety, portion size and body weight: prospective evidence from UK Biobank participants

'Dietary variety' has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = -0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86-82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

Associations of Food Addiction Symptomatology and Disordered Eating Behaviors in a Pre-Surgical Bariatric Population

The construct of food addiction (FA) has been highly debated in recent years particularly in the fields of disordered eating, medical weight management, and bariatric surgery. Some researchers have argued that FA symptoms are distinct, highly prevalent, and present a barrier for patients seeking medical treatment for obesity. The purpose of this study is to evaluate the cross-sectional associations between FA symptomatology, binge eating disorder (BED) and other appetitive traits, as well as dietary quality in a sample of adults with obesity seeking bariatric surgery. This post hoc analysis was conducted on a prospectively collected dataset from August 2020 to August 2022 at a single academic medical center. Descriptive statistics were used to characterize the sample. Additional analyses included: correlation coefficients, multivariable linear regression, and analysis of variance. A total of 587 patients were included in this analysis with low average scores for FA symptoms (mean: 1.48; standard deviation (SD): 2.15). Those with no BED symptoms had the lowest average FA symptoms scores (mean: 0.87; SD: 1.52) and those with both bingeing and LOCE had the highest average scores (mean: 3.35; SD: 2.81). This finding supports the hypothesis that, while related, FA and BED may represent different cognitions and behaviors.

Disentangling the role of NAc D1 and D2 cells in hedonic eating

Overeating is driven by both the hedonic component ('liking') of food, and the motivation ('wanting') to eat it. The nucleus accumbens (NAc) is a key brain center implicated in these processes, but how distinct NAc cell populations encode 'liking' and 'wanting' to shape overconsumption remains unclear. Here, we probed the roles of NAc D1 and D2 cells in these processes using cell-specific recording and optogenetic manipulation in diverse behavioral paradigms that disentangle reward traits of 'liking' and 'wanting' related to food choice and overeating in healthy mice. Medial NAc shell D2 cells encoded experience-dependent development of 'liking', while D1 cells encoded innate 'liking' during the first food taste. Optogenetic control confirmed causal links of D1 and D2 cells to these aspects of 'liking'. In relation to 'wanting', D1 and D2 cells encoded and promoted distinct aspects of food approach: D1 cells interpreted food cues while D2 cells also sustained food-visit-length that facilitates consumption. Finally, at the level of food choice, D1, but not D2, cell activity was sufficient to switch food preference, programming subsequent long-lasting overconsumption. By revealing complementary roles of D1 and D2 cells in consumption, these findings assign neural bases to 'liking' and 'wanting' in a unifying framework of D1 and D2 cell activity.

A role for enjoyment for encouraging fruit consumption

This work investigated the value of highlighting the enjoyment conferred by fruit for encouraging fruit consumption. Study 1 investigated the effects on fruit consumption of visualizing eating fruit that was either enjoyable, not enjoyable, or was unassociated with enjoyment. Study 2 investigated the effects on fruit consumption of health promotion posters that featured either enjoyable or less enjoyable fruit. Both studies used an independent-groups design, where young adults (Study 1, N = 142; Study 2, N = 221) were randomized to conditions, and outcomes: intentions to consume fruit, attitudes towards fruit, immediate fruit selection, subsequent fruit consumption; and a range of characteristics likely to be associated with fruit and vegetable consumption were assessed. In Study 1, higher intentions to consume fruit and more positive attitudes towards fruit were associated with higher likely enjoyment of the fruit visualized, higher fruit liking in general and higher fruit-related self-efficacy (smallest Beta = 0.270, p = 0.02). In Study 2, similar effects were found for likely enjoyment of the fruit featured on a poster; higher likely enjoyment also predicted greater immediate fruit selection (smallest Beta = 0.122, p = 0.03). These outcomes were also associated with variables often associated with fruit and vegetable consumption. Subsequent fruit consumption was only associated with past fruit consumption (smallest Beta = 0.340, p = 0.05). These two studies (Study 1 using visualisation, Study 2 using health promotion posters) highlight a role for enjoyment for encouraging fruit consumption. The value of enjoyment and the simplicity of the poster intervention particularly should be noted.

Effects of different obesogenic diets on joint integrity, inflammation and intermediate monocyte levels in a rat groove model of osteoarthritis

Introduction: Obesogenic diets aggravate osteoarthritis (OA) by inducing low-grade systemic inflammation, and diet composition may affect OA severity. Here, we investigated the effect of diet on joint damage and inflammation in an OA rat model. Methods: Wistar-Han rats (n = 24) were fed a chow, a high-fat (HF) diet, or a high-fat/high-sucrose (HFS) for 24 weeks. OA was induced unilaterally 12 weeks after the diet onset by groove surgery, and compared to sham surgery or no surgical intervention (contralateral limb). Knee OA severity was determined by OARSI histopathology scoring system. At several timepoints monocyte populations were measured using flow cytometry, and joint macrophage response was determined via CD68 immunohistochemistry staining. Results: Groove surgery combined with HF or HFS diet resulted in higher OARSI scores, and both HF and HFS diet showed increased circulating intermediate monocytes compared to chow fed rats. Additionally, in the HFS group, minimal damage by sham surgery resulted in an increased OARSI score. HFS diet resulted in the largest metabolic dysregulation, synovial inflammation and increased CD68 staining in tibia epiphysis bone marrow. Conclusion: Obesogenic diets resulted in aggravated OA development, even with very minimal joint damage when combined with the sucrose/fat-rich diet. We hypothesize that diet-induced low-grade inflammation primes monocytes and macrophages in the blood, bone marrow, and synovium, resulting in joint damage when triggered by groove OA inducing surgery. When the metabolic dysregulation is larger, as observed here for the HFS diet, the surgical trigger required to induce joint damage may be smaller, or even redundant.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Ultra-processed foods in public health nutrition: the unanswered questions

There is a growing interest in the study of the degree of food processing and both health and nutritional outcomes. To that end, several definitions of the degree of processing have been proposed. However, when each of these is used on a common database of nutritional, clinical and anthropometric variables, the observed effect of high intakes of highly processed food, varies considerably.. Moreover, assigning a given food by nutritional experts, to its appropriate level of processing, has been shown to be variable. Thus, the subjective definitions of the degree of food processing and the coding of foods according to these classifications is prone to error is prone to error. Another issue that need resolution is the relative importance of the degree of food processing and the formulation of a processed food. Although correlational studies linking processed food and obesity abound, there is a need for more investigative studies.

Cannabidiol treatment improves metabolic profile and decreases hypothalamic inflammation caused by maternal obesity

Introduction

The implications of maternal overnutrition on offspring metabolic and neuroimmune development are well-known. Increasing evidence now suggests that maternal obesity and poor dietary habits during pregnancy and lactation can increase the risk of central and peripheral metabolic dysregulation in the offspring, but the mechanisms are not sufficiently established. Furthermore, despite many studies addressing preventive measures targeted at the mother, very few propose practical approaches to treat the damages when they are already installed.

Methods

Here we investigated the potential of cannabidiol (CBD) treatment to attenuate the effects of maternal obesity induced by a cafeteria diet on hypothalamic inflammation and the peripheral metabolic profile of the offspring in Wistar rats.

Results

We have observed that maternal obesity induced a range of metabolic imbalances in the offspring in a sex-dependant manner, with higher deposition of visceral white adipose tissue, increased plasma fasting glucose and lipopolysaccharides (LPS) levels in both sexes, but the increase in serum cholesterol and triglycerides only occurred in females, while the increase in plasma insulin and the homeostatic model assessment index (HOMA-IR) was only observed in male offspring. We also found an overexpression of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNFα), interleukin (IL) 6, and interleukin (IL) 1β in the hypothalamus, a trademark of neuroinflammation. Interestingly, the expression of GFAP, a marker for astrogliosis, was reduced in the offspring of obese mothers, indicating an adaptive mechanism to in utero neuroinflammation. Treatment with 50 mg/kg CBD oil by oral gavage was able to reduce white adipose tissue and revert insulin resistance in males, reduce plasma triglycerides in females, and attenuate plasma LPS levels and overexpression of TNFα and IL6 in the hypothalamus of both sexes.

Discussion

Together, these results indicate an intricate interplay between peripheral and central counterparts in both the pathogenicity of maternal obesity and the therapeutic effects of CBD. In this context, the impairment of internal hypothalamic circuitry caused by neuroinflammation runs in tandem with the disruptions of important metabolic processes, which can be attenuated by CBD treatment in both ends.

Heterogeneous effects of individual high-fat diet compositions on phenotype, metabolic outcome, and hepatic proteome signature in BL/6 male mice

The multitude of obesogenic diets used in rodent studies can hardly be overviewed. Since standardization is missing and assuming that individual compositions provoke individual effects, the choice of quality, quantity and combination of diet ingredients seems to be crucial for the outcome and interpretation of obesity studies. Therefore, the present study was conducted to compare the individual effects of three commonly used obesogenic diets, mainly differing in sugar and fat content. Besides basic phenotypic and metabolic characterization, one main aspect was a comparative liver proteome analysis. As expected, the obtained results picture differentiated consequences mainly depending on fat source and/or fat- and sugar quantity. By confirming the general presumption that the choice of nutritional composition is a pivotal factor, the present findings demonstrate that a conscious selection is indispensable for obtaining reliable and sound results in obesity research. In conclusion, we strongly recommend a careful selection of the appropriate diet in advance of a new experiment, taking into account the specific research question.

Scoping Review and Evidence Map of the Relation between Exposure to Dietary Sweetness and Body Weight-Related Outcomes in Adults

Numerous governmental and health organizations recommend reduced intake of added sugars due to the health risks associated with excess intake, including the risk of obesity. Some organizations further recommend avoiding dietary sweetness, regardless of the source. A scoping review and evidence map were completed to characterize the research that investigated associations between dietary sweetness and body weight. The aim was to identify and map published studies that have investigated total dietary sweetness, sweet food/beverages, sugar, or sweetener intake, and body weight-related outcomes and/or energy intake. Using preregistered search terms (osf.io/my7pb), 36,779 publications (duplicates removed) were identified from PubMed, Cochrane Library, and Scopus and screened for inclusion. Eligible studies were clinical trials, longitudinal cohorts, case-control studies, cross-sectional studies, and systematic reviews conducted among adults (age ≥18 y), which were performed to investigate associations between dietary sweetness, sweet foods/beverages, sugar, or sweetener (energetic or nonenergetic) intake and body weight, BMI, adiposity, and/or energy intake. A total of 833 eligible publications were identified, detailing 804 studies. Only 7 studies (0.9% of included studies; 2 clinical trials, 4 cross-sectional studies, and 1 with another design type) investigated associations between total dietary sweetness and body weight-related outcome and/or energy intake. An additional 608 (75.6%) studies investigated intakes of sweet foods/beverages, sugar, or sweetener, and body weight-related outcomes and/or energy intake, including 225 clinical trials, 81 longitudinal cohorts, 4 case-control studies, and 280 cross-sectional studies. Most studies (90.6%) did not measure the sweetness of the diet or individual foods consumed. Ninety-two (11.4%) publications reported data from studies on dietary patterns that included sweet foods/beverages alongside other dietary components and 97 (12.1%) systematic reviews addressed different but related research questions. Although there is a breadth of evidence from studies that have investigated associations between intakes of sweet foods and beverages, sugars, and sweeteners and body weight, there is a limited depth of evidence on the association between total dietary sweetness and body weight.

Reliability and Validity of the Emotional Eater Questionnaire in Romanian Adults

Negative emotions and chronic stress trigger abnormal compensatory behaviors known as emotional eating (EE). EE is a well-known mediator for increased body mass index and weight gain. Our aim was to analyze the factor structure and validity and reliability of the Emotional Eater Questionnaire (EEQ) in a sample of 200 Romanian adults with excess weight. Principal component analysis (PCA) was used to assess the construct validity. The mindful eating questionnaire (MEQ) was used to test concurrent validity. Cronbach’s alpha and Spearman correlations were used to analyze internal and external reliability. The socio-demographic characteristics were used as factors for convergent validity. PCA revealed the existence of three major factors, disinhibition, type of food, and guilt, which accounted for 64.9% of the variance. Concurrent validity showed medium to large associations with MEQ (r = 0.650; p < 0.001) and a large association with the emotional subscale of MEQ (r = 0.732; p < 0.001). Reliability was adequate with Cronbach’s alfa = 0.841 and ICC = 0.775. In a multivariate model, the highest contribution to the EE score was the age (beta = −0.327), followed by feminine gender (beta = 0.321), high levels of perceived stress (beta = 0.215), BMI (beta = 0.184) and lower perceived health status (beta = 0.184). The Romanian version of the EEQ is a reliable and valid tool for measuring emotional eating in adults with excess weight.

Ultra-processed foods in public health nutrition: the unanswered questions

There is a growing interest in the study of the degree of food processing and both health and nutritional outcomes. To that end, several definitions of the degree of processing have been proposed. However, when each of these is used on a common database of nutritional, clinical and anthropometric variables, the observed effect of high intakes of highly processed food, varies considerably.. Moreover, assigning a given food  by nutritional experts, to its appropriate level of processing, has been shown to be variable. Thus, the subjective definitions of the degree of food processing and the coding of foods according to these classifications is prone to error  is  prone to error. Another issue that need resolution is the relative importance of the degree of food processing and the formulation of a processed food. Although correlational studies linking processed food and obesity abound, there is a need for more investigative studies.

Distinct factors associated with short-term and long-term weight loss induced by low-fat or low-carbohydrate diet intervention

To understand what determines the success of short- and long-term weight loss, we conduct a secondary analysis of dietary, metabolic, and molecular data collected from 609 participants before, during, and after a 1-year weight-loss intervention with either a healthy low-carbohydrate (HLC) or a healthy low-fat (HLF) diet. Through systematic analysis of multidomain datasets, we find that dietary adherence and diet quality, not just caloric restriction, are important for short-term weight loss in both diets. Interestingly, we observe minimal dietary differences between those who succeeded in long-term weight loss and those who did not. Instead, proteomic and gut microbiota signatures significantly differ between these two groups at baseline. Moreover, the baseline respiratory quotient may suggest a specific diet for better weight-loss outcomes. Overall, the identification of these dietary, molecular, and metabolic factors, common or unique to the HLC and HLF diets, provides a roadmap for developing individualized weight-loss strategies.

Utility of 'substance use disorder' as a heuristic for understanding overeating and obesity

Rates of obesity and obesity-associated diseases have increased dramatically in countries with developed economies. Substance use disorders (SUDs) are characterized by the persistent use of the substance despite negative consequences. It has been hypothesized that overconsumption of palatable energy dense food can elicit SUD-like maladaptive behaviors that contribute to persistent caloric intake beyond homeostatic need even in the face of negative consequences. Palatable food and drugs of abuse act on many of the same motivation-related circuits in the brain, and can induce, at least superficially, similar molecular, cellular, and physiological adaptations on these circuits. As such, applying knowledge about the neurobiological mechanisms of SUDs may serve as useful heuristic to better understand the persistent overconsumption of palatable food that contributes to obesity. However, many important differences exist between the actions of drugs of abuse and palatable food in the brain. This warrants caution when attributing weight gain and obesity to the manifestation of a putative SUD-related behavioral disorder. Here, we describe similarities and differences between compulsive drug use in SUDs and overconsumption in obesity and consider the merit of the concept of "food addiction".

A new apparatus to analyze meal-related ingestive behaviors in rats fed a complex multi-food diet

The measurement of the size and timing of meals provides critical insight into the processes underlying food intake. While most work has been conducted with a single food or fluid, the availability of food choices can also influence eating and interact with these processes. The 5-Item Food Choice Monitor (FCM), a device that continuously measures eating and drinking behaviors of rats provided up to 5 foods and 2 fluids simultaneously, was designed to allow study of food choices simultaneously with meal patterns. To validate this device, adult male and female (n = 8 each) Sprague-Dawley rats were housed in the FCM. Food and fluid intake were measured continuously (22-h/day) while rats were presented water and powdered chow. Then a cafeteria diet of 5 foods varying in macronutrient content, texture, and flavors were offered along with water. Lastly, the 5 foods were offered along with 0.3 M sucrose and water. Analyses were conducted to find optimal criteria for parceling ingestive behavior into meals, and then meal patterns were quantified. Total intake, as assessed by FCM software, was in good concordance with that measured by an independent scale. A minimum meal size of 1 kcal and a meal termination criterion of 15-min accounted for >90% of total intake and produced meal dynamics that were in register with the literature. Use of the cafeteria diet allowed comparisons between meal patterns with a single food versus a multi-food diet, as well as analyses of macronutrient-related food choices across subsets of meals. The FCM proved to accurately measure food intake over a 22-h period and was able to detect differences and similarities in the meal patterns of rats as a function of sex and food choice availability. Combined with any number of experimental manipulations, the FCM holds great promise in the investigation of the physiological and neural controls of ingestive behavior in a dietary environment that allows food choices, more closely emulating human eating conditions.

Change in craving and frequency of consuming palatable foods for non-homeostatic motives after a gut-cued eating intervention

INTRODUCTION

Little is known regarding consumption of palatable foods (PFs) for non-homeostatic reasons after weight-loss interventions and if baseline or change in frequency of this kind of eating can predict weight-loss outcomes. Little is also known of the relationship between PF eating for non-homeostatic motives and PF craving. Addressing these gaps is important because cravings and habitual consumption of PFs in the absence of homeostatic need contribute to obesity.

METHODS

N = 30 adults with a mean 34.8 BMI completed a seven-response choice version of the PEMS (PEMS-7) before and after Gut-Cued Eating (GCE), an intervention that did not ban PFs but instructed them to eat only when stomach-hungry and stop eating before feeling too full. Photos of PFs were also rated pre- and post-GCE.

RESULTS

Frequency of eating PFs for social, reward enhancement, and coping, but not conformity motives, decreased after GCE. The decreases predicted amount of weight loss independent of initial weight and demographics. PF craving also decreased and, while correlated with decreasing PF intake, it did not predict weight loss.

DISCUSSION

The study is preliminary because GCE was uncontrolled. However, results warrant a controlled investigation. That craving and frequency of consuming PFs for non-homeostatic motives declined with an intervention that did not ban PFs suggests a method that may voluntarily decrease one's intake of PFs. This should facilitate weight-loss and healthy-weight maintenance. Finally, decreased eating for non-homeostatic motives suggests that individuals were no longer using PFs to cope, socialize, and enhance reward, a change with benefits beyond weight loss.

Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models

The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake (“eat less”) and increase energy expenditure (“move more”). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that this approach rests on an erroneous paradigm. A new formulation of the energy balance model (EBM), like prior versions, considers overeating (energy intake > expenditure) the primary cause of obesity, incorporating an emphasis on “complex endocrine, metabolic, and nervous system signals” that control food intake below conscious level. This model attributes rising obesity prevalence to inexpensive, convenient, energy-dense, “ultra-processed” foods high in fat and sugar. An alternative view, the carbohydrate-insulin model (CIM), proposes that hormonal responses to highly processed carbohydrates shift energy partitioning toward deposition in adipose tissue, leaving fewer calories available for the body’s metabolic needs. Thus, increasing adiposity causes overeating to compensate for the sequestered calories. Here, we highlight robust contrasts in how the EBM and CIM view obesity pathophysiology and consider deficiencies in the EBM that impede paradigm testing and refinement. Rectifying these deficiencies should assume priority, as a constructive paradigm clash is needed to resolve long-standing scientific controversies and inform the design of new models to guide prevention and treatment. Nevertheless, public health action need not await resolution of this debate, as both models target processed carbohydrates as major drivers of obesity.

Role of the striatal dopamine, GABA and opioid systems in mediating feeding and fat intake

Food intake, which is a highly reinforcing behavior, provides nutrients required for survival in all animals. However, when fat and sugar consumption goes beyond the daily needs, it can favor obesity. The prevalence and severity of this health problem has been increasing with time. Besides covering nutrient and energy needs, food and in particular its highly palatable components, such as fats, also induce feelings of joy and pleasure. Experimental evidence supports a role of the striatal complex and of the mesolimbic dopamine system in both feeding and food-related reward processing, with the nucleus accumbens as a key target for reward or reinforcing-associated signaling during food intake behavior. In this review, we provide insights concerning the impact of feeding, including fat intake, on different types of receptors and neurotransmitters present in the striatal complex. Reciprocally, we also cover the evidence for a modulation of palatable food intake by different neurochemical systems in the striatal complex and in particular the nucleus accumbens, with a focus on dopamine, GABA and the opioid system.

How Does the University Food Environment Impact Student Dietary Behaviors? A Systematic Review

The food environment has been implicated in creating an obesogenic generation; and while previous research has focused on population-wide initiatives, the university population resides in a research gap. To explore detailed components of the university food environment and what shaped dietary behaviors, we retrieved literature from the following databases: ScienceDirect, Scopus, PubMed, Medline, and EMBASE. Eleven studies were identified for qualitative content analysis and study quality assessment identified most of the studies as of good quality (n 8) and some as of fair quality (n 3). The certainty of evidence remained at a low level for all (n 11) studies due to the cross-sectional, observational nature of studies. Three major themes emerged: (1) food environment, (2) student perceptions (SPs), and (3) dietary outcome (DO). In a university food environment, the taste of food was paramount for the food choices of students, followed by the availability of food and the price of food. When university students perceive and choose foods and beverages, they sometimes regard unhealthy foods and beverages as healthy options. The diet quality of university students is more susceptible to living arrangements and socioeconomic status, but higher salt, fat, and added sugar consumption generally resulted in poorer quality of diet on campus. Future research could use novel methods to explore a wider range and deeper level of students' dietary behavior determinants in university food environments.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021283562.

Examining the validity and consistency of the Adult Eating Behaviour Questionnaire-Español (AEBQ-Esp) and its relationship to BMI in a Mexican population

PURPOSE

Appetitive traits in adults and their associations with weight can be measured using the Adult Eating Behaviour Questionnaire (AEBQ). The aim of this study was to confirm the factor structure of the Spanish AEBQ (AEBQ-Esp) in a Mexican sample and explore associations between the eight traits with body mass index (BMI).

METHOD

A sample of 1023 adults, mean age of 36.8 ± 12.8 years, was recruited from Guadalajara, Mexico. Researchers weighed and measured participants, and they completed the AEBQ-Esp either online or in paper format and reported sociodemographic data. To test two alternative factor structures (eight factors including Hunger; seven factors excluding Hunger), confirmatory factor analysis (CFA) was used. Internal reliability was assessed using Cronbach's alpha; test-retest reliability was assessed using intra-class correlation coefficients. Multivariate linear regressions were used to test for associations between the AEBQ subscales and BMI, adjusted for age, sex, format of AEBQ responses, education, marital and employment status.

RESULTS

A seven-factor structure was the best model fit using CFA, excluding the Hunger subscale but similar to the original AEBQ. Internal reliability was good for all subscales (Cronbach's α = 0.70-0.86), and the intra-class correlation coefficient (0.70-0.91) reflected good test-retest reliability. In the fully adjusted models, Satiety Responsiveness [β = - 0.61; (- 1.01, - 0.21)] and Slowness in Eating [β = - 0.70; (- 1.01, - 0.39)] were negatively associated with BMI, and Emotional Over-Eating [β = 0.94; (0.62, 1.27)] was positively associated with BMI.

CONCLUSIONS

The AEBQ-Esp (excluding Hunger) appears to be a valid and reliable psychometric questionnaire for measuring appetitive traits in a Mexican Spanish-speaking population. Some traits appear to be associated with BMI in adulthood and warrant further exploration.

LEVEL OF EVIDENCE

Level III evidence obtained from well-designed cohort or case-control analytic studies. Although this was just an observational study, it was well designed and provided new evidence.

Snack Package Size and Variety Differentially Influence Energy Intake and Food Choices in Healthy Adults

BACKGROUND

While energy and nutritional content of snacks can contribute to overconsumption, other factors within the modern food environment may also influence the amount and types of snacks consumed.

OBJECTIVES

The aim was to examine whether snack package size and variety influence free-living snacking behavior in healthy adults. The impact of intuitive eating score on snacking behavior was also examined.

METHODS

Thirty adults [age: 23.6 ± 0.8 y; BMI (kg/m2): 22.8 ± 0.5] participated in a randomized crossover-design study. Participants were provided, in randomized order, with the following isocaloric snack exposures to consume for 3 d/exposure-1) CONTROL: highly appealing/appetizing snacks (e.g., dessert snacks, candy, savory snacks, fruits and vegetables, protein snacks); 2) LARGE-PACKAGE: similar snacks as CONTROL but in larger package sizes; and 3) VARIETY: larger variety of snacks. The primary outcomes included the 3-d average ad libitum snack energy, macronutrient content, and food choices for each snack exposure. The secondary outcome was the intuitive eating score and snacking behavior.

RESULTS

LARGE-PACKAGE increased snack intake by 11.9% (1150 ± 81 kcal) compared with CONTROL (1030 ± 71 kcal, P = 0.04), whereas VARIETY snack intake (1030 ± 69 kcal) was no different from CONTROL (P = 1.0). LARGE-PACKAGE increased consumption of desserts compared with CONTROL (P = 0.03) and VARIETY (P = 0.02). Alternately, VARIETY increased consumption of fruits and vegetables compared with LARGE-PACKAGE (P = 0.01) and CONTROL (P = 0.01). Intuitive eating score was not significantly associated with snack intake or snack choice (all, P > 0.05).

CONCLUSIONS

Snack package size and variety differentially influence energy intake and food choices in healthy adults. This trial was registered atclinicaltrials.gov (NCT03940105).

Food Reward after a Traditional Inuit or a Westernised Diet in an Inuit Population in Greenland

The food availability and dietary behaviours in Greenland have changed with increasing Westernisation. Food reward is an important driver of food choice and intake, which has not previously been explored in the Arctic population. The aim of this study was to explore differences in food reward after a four-week intervention period with a traditional Inuit diet (TID) or Westernised diet (WD) in Inuit populations in Northern and Western Greenland. This cross-sectional analysis included 44 adults (n = 20 after TID and n = 24 after WD). We assessed the food reward components, explicit liking and implicit wanting, using the Leeds Food Preference Questionnaire under standardised conditions 60 min after drinking a glucose drink as part of an oral glucose tolerance test after four weeks following a TID or WD. The food intake was assessed using food frequency questionnaires. The intervention groups differed only in implicit wanting for high-fat sweet foods, with higher implicit wanting among the participants following TID compared to WD. Both groups had lower explicit liking and implicit wanting for sweet relative to savoury foods and for high-fat relative to low-fat foods. This exploratory study can guide future studies in Inuit populations to include measures of food reward to better understand food intake in the Arctic.

Perceived acceptability of partial enteral nutrition (PEN) using oral nutritional supplement drinks in adolescent and adult Crohn's disease outpatients: A feasibility study

BACKGROUND AND AIMS

Studies, mainly in Japanese cohorts, have shown that partial enteral nutrition (PEN) including oral nutritional supplement (ONS) drinks can prolong disease remission and increase drug effectiveness in Crohn's disease (CD). Acceptability is a key feasibility parameter to determine whether PEN is a viable treatment option in UK CD patients. We report the results of a single centre cross-sectional feasibility study carried out to investigate perceived acceptability of PEN using ONS drinks and whether ONS preference varies with sex, nutritional status or phenylthiocarbamide (PTC) sensitivity.

METHODS

Patients with a confirmed CD diagnosis were recruited using convenience sampling from an adult and adolescent gastroenterology outpatient clinic over 3 years. Blind taste testing of 5 polymeric ONS drinks were conducted using a validated 9-point hedonic rating scale followed by completion of an acceptability questionnaire based on the preferred ONS drink. A subset of patients took home the preferred ONS drink for a 7-day ONS study.

RESULTS

105 CD patients (55 males), aged 34.9 (±15.4) years were recruited and 28 patients completed the 7-day ONS study. Overall impression scores did not significantly vary with nutritional status, sex, BMI, handgrip strength (HGS), mid-upper arm circumference (MUAC) or PTC sensitivity. Ensure plus milkshake™ rated highest for overall impression (6.5, p=<0.0001) and all other organoleptic properties (p < 0.0001). The main perceived benefits of using ONS drinks as PEN related to assurance of nutrient intake (89%), convenience (86%), and improvement of gut symptoms (85%). The main perceived barriers related to reduction in pleasure from eating and drinking (56%), struggling with drink storage (54%) having less energy and feeling more tired than if eating 3 solid meals daily (52%). 65% of patients would consider using ONS drinks as PEN as a maintenance treatment option. 81% of patients felt confident-very confident about consuming ONS drinks daily as PEN for three months but this dropped to 64% and 37% at 6 and 12 months, respectively. There was a significant drop in perceived ease of use of ONS drinks as PEN after the 7-day ONS study (P = 0.01).

CONCLUSION

Use of ONS drinks as PEN have high perceived benefits and appear to be a feasible option for short-term use of 3-6 months in CD patients. However, confidence in long-term use of ONS drinks as PEN is low mainly due to the perceived social impact. Future studies should assess longer trial periods and volume of ONS drinks to increase the validity of these findings.

Finding the Sweet Spot: Measurement, Modification, and Application of Sweet Hedonics in Humans

Sweetness is a sensation that contributes to the palatability of foods, which is the primary driver of food choice. Thus, understanding how to measure the appeal (hedonics) of sweetness and how to modify it are key to effecting dietary change for health. Sweet hedonics is multidimensional so can only be captured by multiple approaches including assessment of elements such as liking, preference, and consumption intent. There are both innate and learned components to the appeal of sweet foods and beverages. These are responsive to various behavioral and biological factors, suggesting the opportunity to modify intake. Given the high amount of added sugar intake in the United States and recommendations from many groups to reduce this, further exploration of current hypothesized approaches to moderate sugar intake (e.g., induced hedonic shift, use of low-calorie sweeteners) is warranted.

The carbohydrate-insulin model: a physiological perspective on the obesity pandemic

According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public health failure may arise from a fundamental limitation of the EBM itself. Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain. An alternative paradigm, the carbohydrate-insulin model (CIM), proposes a reversal of causal direction. According to the CIM, increasing fat deposition in the body-resulting from the hormonal responses to a high-glycemic-load diet-drives positive energy balance. The CIM provides a conceptual framework with testable hypotheses for how various modifiable factors influence energy balance and fat storage. Rigorous research is needed to compare the validity of these 2 models, which have substantially different implications for obesity management, and to generate new models that best encompass the evidence.

Post-oral sensing of fat increases food intake and attenuates body weight defense

In mammals, changes in weight elicit responses that favor a return to one's previous weight and promote weight stability. It has been hypothesized that palatable sweet and high-fat foods disturb the defense of body weight, leading to weight gain. We find that increasing sweetness or percent calories from fat increases diet palatability but that only increases in nutritive fat content increase caloric intake and body weight. In a mouse model of overfeeding that activates weight defense, high-fat diets, but not sweetened diets, attenuate the defense of body weight, leading to weight gain. The ability of a palatable, high-fat diet to increase food intake does not require tasting or smelling the food. Instead, the direct infusion of a high-fat diet into the stomach increases the ad libitum intake of less palatable, low-fat food. Post-oral sensing of percent calories from fat modulates feeding behavior to alter weight stability.

Empirico-inductive and/or hypothetico-deductive methods in food science and nutrition research: which one to favor for a better global health?

Scientific research generally follows two main methods: empirico-inductive (EI), gathering scattered, real-world qualitative/quantitative data to elaborate holistic theories, and the hypothetico-deductive (HD) approach, testing the validity of hypothesized theory in specific conditions, generally according to reductionist methodologies or designs, with the risk of over simplifying the initial complexity empirically perceived in its holistic view. However, in current food and nutrition research, new hypotheses are often elaborated from reductionist data obtained with the HD approach, and aggregated to form (ultra)reductionist theories, with no application of EI observations, limiting the applicability of these hypotheses in real life. This trend and the application of the EI method are illustrated as regards with the global health issue through the examples of food classifications/scoring, clinical studies, the definition of a sustainable diet, the "matrix effect"-related hypothesis, the concept of healthy core metabolism, and obesity prevention within the perspective of social sciences. To be efficient for producing food and nutritional data appropriable by the society, it finally appears that not only both approaches are necessary, starting with the EI method then the HD one, but also a back and forth between the two, this being not always realized, potentially leading to confusion and misunderstanding in society.

Sensory and physical characteristics of foods that impact food intake without affecting acceptability: Systematic review and meta-analyses

This systematic review with meta-analyses aimed to identify the sensory and physical characteristics of foods/beverages which increase satiation and/or decrease/delay subsequent consumption without affecting acceptability. Systematic searches were first undertaken to identify review articles investigating the effects of any sensory and physical food characteristic on food intake. These articles provided some evidence that various textural parameters (aeration, hardness, homogeneity, viscosity, physical form, added water) can impact food intake. Individual studies investigating these effects while also investigating acceptability were then assessed. Thirty-seven individual studies investigated a textural manipulation and provided results on food intake and acceptability, 13 studies (27 comparisons, 898 participants) investigated effects on satiation, and 29 studies (54 comparisons, 916 participants) investigated effects on subsequent intake. Meta-analyses of within-subjects comparisons (random-effects models) demonstrated greater satiation (less weight consumed) from food products that were harder, chunkier, more viscous, voluminous, and/or solid, while demonstrating no effects on acceptability. Textural parameters had limited effects on subsequent consumption. Between-subjects studies and sensitivity analyses confirmed these results. These findings provide some evidence that textural parameters can increase satiation without affecting acceptability. The development of harder, chunkier, more viscous, voluminous, and/or solid food/beverage products may be of value in reducing overconsumption.

Low Carbohydrate Dietary Approaches for People With Type 2 Diabetes-A Narrative Review

Although carbohydrate restriction is not a new approach for the management of Type 2 diabetes, interest in its safety and efficacy has increased significantly in recent years. The purpose of the current narrative review is to summarise the key relevant research and practical considerations in this area, as well as to explore some of the common concerns expressed in relation to the use of such approaches. There is a strong physiological rationale supporting the role of carbohydrate restriction for the management of Type 2 diabetes, and available evidence suggests that low carbohydrate dietary approaches (LCDs) are as effective as, or superior to, other dietary approaches for its management. Importantly, LCDs appear to be more effective than other dietary approaches for facilitating a reduction in the requirement for certain medications, which leads to their effects on other health markers being underestimated. LCDs have also been demonstrated to be an effective method for achieving remission of Type 2 diabetes for some people. The available evidence does not support concerns that LCDs increase the risk of cardiovascular disease, that such approaches increase the risk of nutrient deficiencies, or that they are more difficult to adhere to than other dietary approaches. A growing number of organisations support the use of LCDs as a suitable choice for individuals with Type 2 diabetes.

Dopamine D1 receptor signalling in the lateral shell of the nucleus accumbens controls dietary fat intake in male rats

Central dopamine signaling regulates reward-related aspects of feeding behavior, and during diet-induced obesity dopamine receptor signaling is altered. Yet, the influence of dopamine signaling on the consumption of specific dietary components remains to be elucidated. We have previously shown that 6-hydroxydopamine-mediated lesions of dopamine neuron terminals in the lateral shell of the nucleus accumbens promotes fat intake in rats fed a multi-component free-choice high-fat high-sugar (fcHFHS) diet. It is however not yet determined which dopamine receptors are responsible for this shift towards fat preference. In this study, we assess the effects of D1-or D2 receptor acute inhibition in the lateral shell of the nucleus accumbens on fcHFHS diet consumption. We report that infusion of the D1 receptor antagonist SCH2 3390, but not the D2 receptor antagonist raclopride, promotes dietary fat consumption in male Sprague Dawley rats on a fcHFHS diet during 2 h after infusion. Furthermore, anatomical analysis of infusion sites revealed that the rostral region, but not the caudal region, of the lateral shell of the nucleus accumbens is sensitive to the D1 receptor inhibition effects on fat consumption. Our data highlight a role for D1 receptors in the rostral region of the lateral shell of the nucleus accumbens to control dietary fat consumption.

Effect of Gazpacho, Hummus and Ajoblanco on Satiety and Appetite in Adult Humans: A Randomised Crossover Study

Nowadays, overweight and obesity has reached an epidemic level around the world. With the aim to tackle them, an interesting strategy is the study of food and ingredients with satiety properties. In addition to reducing food and/or calorie intake, this type of foods must be included as part of a healthy diet. With regard to this, it is well known that the Mediterranean Diet (MD) is a feeding pattern that helps us to maintain good health, providing an adequate intake of micronutrients and active compounds. With this background, the main aim of this research was to identify MD foods with a high satiating potential capacity. For this purpose, three typical foods of the Mediterranean region, mainly based on vegetables, were selected: hummus, ajoblanco and gazpacho. As a control, white bread was used. Twenty-four human healthy volunteers consumed a standard breakfast followed by the different typical Mediterranean foods, and then the subjective sensation of hunger and satiety for each food was assessed by visual analogue scales (VAS) during 3 h. Subsequently, volunteers had ad libitum access to a standard meal. The results indicate that gazpacho showed the highest satiating scores, despite the fact that it was not the food that provided the highest protein or fibre amount. More studies of this type are needed to determine the proportion and/or combination of ingredients from these classical Mediterranean recipes that could enhance human satiety.

Feasibility and Acceptability of a Healthy Nordic Diet Intervention for the Treatment of Depression: A Randomized Controlled Pilot Trial

Healthy diet interventions have been shown to improve depressive symptoms, but there is a need for randomized controlled trials (RCTs) that are double blind and investigate biological mechanisms. The primary objectives of this randomized controlled pilot trial were to test the palatability of the meals and the acceptability of the intervention in preparation for an 8-week RCT in the future, which will investigate whether a healthy Nordic diet improves depressive symptoms in individuals with major depressive disorder, and associated biological mechanisms. Depressed (n = 10) and non-depressed (n = 6) women and men were randomized to receive either a healthy Nordic diet (ND) or a control diet (CD) for 8 days. Participants were blinded to their diet allocation and the study hypotheses. Health questionnaires were completed before and after the intervention and, throughout the study, questionnaires assessed participants’ liking for the meals, their sensory properties, adherence, and open-ended feedback. In the ND group, 75% of participants consumed only the provided foods, as instructed, compared to 50% of CD participants. The meals of both diets, on average, received good ratings for liking and sensory properties, though the ND ratings were somewhat higher. Overall, results were positive and informative, indicating that the planned RCT will be feasible and well-accepted, with some proposed modifications.

Reward-related neural correlates in adolescents with excess body weight

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We examined non-food reward related neural correlates of body mass index (BMI) in adolescents.

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High BMI z-score relates to heightened reward salience during reward anticipation.

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High BMI z-score relates to heightened reward salience when receiving feedback about reward.

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Deficits in inhibitory control networks are shown in adolescents with high BMI z-score.

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Reward and inhibitory control network impairments may lead to impulsive behavior.

The functional and connectivity reward processing in adults with excessive body weight is well documented, though is relatively less researched during adolescence. Given that reward and inhibition may be highly malleable during adolescence, it is unknown how impulsive behaviors, potentially stemming from impaired inhibitory control and heightened sensitivity to rewarding cues, relate to increases in body weight in adolescents. Adolescents (N = 76; mean age = 14.10 years, SD = 1.92) with varied body mass index (BMI) performed a child-friendly monetary incentive delay task during functional magnetic resonance imaging, to study reward processing during the anticipation of rewards (cue) and reactions to feedback about rewards (feedback). Our results show that adolescents with greater BMI z-score show neural activation and ventral striatum connectivity alterations in networks implicated in reward, salience detection, and inhibitory control. These bottom-up reward and top-down inhibitory control networks, as well as interactions between these networks were prevalent during the anticipation period (when the cue is presented) as well as when receiving feedback about whether one has received a reward. Specifically, our results were mainly driven by failure to receive a reward in the feedback period, and the anticipation of a potential reward in the anticipation period. Overall, we provide evidence for heightened reward salience as well as inhibitory control deficits that, in combination, may contribute to the impulsive behaviors that lead to higher BMI in adolescents.

Early changes in appetite and energy expenditure are not associated to body weight and fat losses in pre-menopausal women living with overweight/obesity

BACKGROUND

The aim of the study was to investigate whether early changes (1-week) in energy balance-related measures would predict changes in body weight (BW) and fat losses in women living with overweight/obesity.

METHODS

BW, body composition (DXA), resting energy expenditure (REE)(indirect calorimetry), olfactory performance (Sniffin' Sticks), appetite and palatability (visual analogue scale) were measured at baseline, after a 1-week of caloric restriction as well as post-intervention (at 10 and 20 weeks) in a group of 30 women living with overweight/obesity.

RESULTS

A significant decrease in REE (p = 0.033) was noted after 1 week. Fasting desire to eat (p = 0.004), hunger (p = 0.001) and prospective food consumption (p = 0.001) all increased after 1 week. Similarly, significant increases in AUC SQ for desire to eat (p = 0.01), hunger (p = 0.005) and prospective food consumption (p = 0.001) were noted after 1 week. However, these early changes were not associated to final BW or FM losses at the end of the weight loss intervention.

CONCLUSION

Despite significant changes in REE and appetite soon after the onset of a BW loss intervention, these early changes do not seem to predict final BW or FM losses at the end of the program in women living with overweight/obesity.

Manipulation of fatty acid composition in a high-fat meal does not result in differential alterations in appetite or food intake in normal weight females: A single-blind randomized crossover study

A behavioral concept that generates a path to obesity is eating in the absence of hunger (EAH). One strategy that may be effective in preventing EAH is the manipulation of dietary fatty acid (FA) composition. However, it remains unclear which FA has the greatest impact on both appetite and EAH. Therefore, the purpose of this study was to examine the effect of different dietary FA compositions (monounsaturated, MUFA; polyunsaturated, PUFA; saturated, SFA) on subjective ratings of appetite and subsequent ad libitum eating after a 3 h postprandial period. Sixteen apparently healthy normal weight females between ages 18-40 completed this randomized, single-blind, crossover study. Participants consumed a HF meal (65% energy from fat) rich in SFA, MUFA, and PUFA with an energy content corresponding to 35% of their measured resting metabolic rate on three separate occasions. Visual analog scales were collected while fasted and every 30 min for 3 h during a postprandial period to measure feelings of hunger, fullness, and desire to eat (DTE). Participants were provided an ad libitum buffet meal 3 h after the HF meal. There were no statistically significant differences for ratings of hunger, fullness, or DTE across conditions. Further, there was no significant difference in energy intake during the ad libitum lunch. We conclude that the manipulation of FA composition in a HF meal does not differentially affect appetite sensations or subsequent energy intake.

The efficacy of essential amino acid supplementation for augmenting dietary protein intake in older adults: implications for skeletal muscle mass, strength and function

The primary aim of this review is to evaluate the efficacy of essential amino acid (EAA) supplementation as a strategy to increase dietary protein intake and improve muscle mass, strength and function in older adults. A sufficient daily protein intake is widely recognised to be fundamental for the successful management of sarcopenia in older undernourished adults. In practice, optimising protein intakes in older adults is complex, requiring consideration of the dose and amino acid composition (i.e. a complete EAA profile and abundant leucine content) of ingested protein on a per meal basis, alongside the age-related decline in appetite and the satiating properties of protein. Recent studies in older adults demonstrate that EAA-based supplements are non-satiating and can be administered alongside food to enhance the anabolic properties of a meal containing a suboptimal dose of protein; an effect magnified when combined with resistance exercise training. These findings support the notion that EAA supplementation could serve as an effective strategy to improve musculoskeletal health in older adults suffering from non-communicable diseases such as sarcopenia. Compliance is critical for the long-term success of complex interventions. Hence, aspects of palatability and desire to eat are important considerations regarding EAA supplementation. In conclusion, EAA-based supplements enriched with l-leucine offer an alternative strategy to whole protein sources to assist older adults in meeting protein recommendations. In practice, EAA supplements could be administered alongside meals of suboptimal protein content, or alternatively between meals on occasions when older adults achieve their per meal protein intake recommendations.

The cafeteria diet: A standardized protocol and its effects on behavior

Obesity is a major health risk, with junk food consumption playing a central role in weight gain, because of its high palatability and high-energy nutrients. The Cafeteria (CAF) diet model for animal experiments consists of the same tasty but unhealthy food products that people eat (e.g. hot dogs and muffins), and considers variety, novelty and secondary food features, such as smell and texture. This model, therefore, mimics human eating patterns better than other models. In this paper, we systematically review studies that have used a CAF diet in behavioral experiments and propose a standardized CAF diet protocol. The proposed diet is ad libitum and voluntary; combines different textures, nutrients and tastes, including salty and sweet products; and it is rotated and varied. Our summary of the behavioral effects of CAF diet show that it alters meal patterns, reduces the hedonic value of other rewards, and tends to reduce stress and spatial memory. So far, no clear effects of CAF diet were found on locomotor activity, impulsivity, coping and social behavior.

Hedonic contrast and the short-term stimulation of appetite

Hedonic contrast describes how liking for one item is influenced by the recent experience of other items which differ in hedonic valence. In the context of food stimuli, there is abundant evidence that hedonic contrast alters liking, but limited information on its impact on intake, and the aim here was to further clarify how hedonic impact modifies intake. Participants (96 female volunteers) rated and consumed ad libitum a sequence of four bowls of a snack (potato crisps) in one of three conditions. In the Palatable (salted crisps) and Bland (unsalted crisps) conditions, all four bowls were the same. In the Contrast condition participants alternated between salted and unsalted crisps. In total, significantly more was consumed in the Palatable (35.0 ± 2.6 g) than Bland (26.6 ± 2.4 g) condition, but most was consumed in the Contrast condition (37.0 ± 1.6 g). The impact of hedonic contrast was seen in the third serving, where those in the Contrast condition consumed the most of any serving, and significantly more than in Palatable or Bland conditions, and at the final serving, when those in the Contrast condition consumed significantly less than in Bland or Palatable conditions. Rated liking for the foods showed a similar pattern, with liking decreasing across servings in Palatable and Bland conditions. However, liking was influenced by the preceding serving in the Contrast condition, and the change in liking produced by contrast predicted subsequent intake. Overall, these data provide clear evidence that hedonic contrast can influence consumption, with intake driven by this adjusted liking.

Effect of Physical Exercise on Taste Perceptions: A Systematic Review

The effect of physical exercise on nutrition has gained substantial interest in the last decade. Meaningful results have been produced concerning the effect of physical exercise on different appetite hormones and food choice/preference. While it is well known that taste and nutrition are related, the relation between taste and physical activity has not yet been fully explored. This systematic review aims to provide a detailed view of the literature on physical exercise and its effect on taste perceptions. Five tastes were included in this review: sweet, salty, bitter, sour, and umami. Sweet taste intensity, sensitivity, and preference were increased by acute physical exercise, but sweet preference was reduced by chronic physical activity. Perceived intensity and sensitivity decreased overall for salty taste, but an increased preference was noted during/following exercise. Sour taste intensity ratings were decreased following exercise and preference was enhanced. Umami taste intensity and sensitivity increased following exercise and preference was decreased. No significant results were obtained for bitter taste. While evidence regarding the effect of exercise on taste has arisen from this review, the pre-testing nutrition, testing conditions, type of test, and exercise modality must be standardized in order to produce meaningful and reproducible results in the future.

Hindbrain Double-Negative Feedback Mediates Palatability-Guided Food and Water Consumption

Hunger and thirst have distinct goals but control similar ingestive behaviors, and little is known about neural processes that are shared between these behavioral states. We identify glutamatergic neurons in the peri-locus coeruleus (periLC^VGLUT2 neurons) as a polysynaptic convergence node from separate energy-sensitive and hydration-sensitive cell populations. We develop methods for stable hindbrain calcium imaging in free-moving mice, which show that periLC^VGLUT2 neurons are tuned to ingestive behaviors and respond similarly to food or water consumption. PeriLC^VGLUT2 neurons are scalably inhibited by palatability and homeostatic need during consumption. Inhibition of periLC^VGLUT2 neurons is rewarding and increases consumption by enhancing palatability and prolonging ingestion duration. These properties comprise a double-negative feedback relationship that sustains food or water consumption without affecting food- or water-seeking. PeriLC^VGLUT2 neurons are a hub between hunger and thirst that specifically controls motivation for food and water ingestion, which is a factor that contributes to hedonic overeating and obesity.

An Afternoon Hummus Snack Affects Diet Quality, Appetite, and Glycemic Control in Healthy Adults

BACKGROUND

Snacking continues to be a major component in the dietary patterns of most Americans despite conflicting evidence surrounding snacking healthfulness. Low-sugar, highly nutritive snacks, such as hummus, can lead to improvements in diet quality, appetite, and glycemic control.

OBJECTIVES

The purpose of the study was to examine the effects of afternoon snacking on diet quality, appetite, and glycemic control in healthy adults.

METHODS

Thirty-nine adults (age: 26 ± 1 y; BMI: 24.4 ± 0.5 kg/m2) randomly completed the following afternoon snack patterns for 6 d/pattern: hummus and pretzels [HUMMUS; 240 kcal; 6 g protein, 31 g carbohydrate (2 g sugar), 11 g fat]; granola bars [BARS; 240 kcal; 4 g protein, 38 g carbohydrate (16 g sugar), 9 g fat]; or no snacking (NO SNACK). On day 7 of each pattern, a standardized breakfast and lunch were provided. The respective snack was provided to participants 3 h after lunch, and appetite, satiety, and mood questionnaires were completed throughout the afternoon. At 3 h postsnack, a standardized dinner was consumed, and an evening snack cooler was provided to be consumed, ad libitum at home, throughout the evening. Lastly, 24 h continuous glucose monitoring was performed.

RESULTS

HUMMUS reduced subsequent snacking on desserts by ∼20% compared with NO SNACK (P = 0.001) and BARS (P < 0.001). HUMMUS led to greater dietary compensation compared with BARS (122 ± 31% compared with 72 ± 32%, respectively; P < 0.05). HUMMUS reduced indices of appetite (i.e., hunger, desire to eat, and prospective food consumption) by ∼70% compared with NO SNACK (all P < 0.05), whereas BARS did not. Additionally, satiety was ∼30% greater following HUMMUS and BARS compared with NO SNACK (both P < 0.005) with no differences between snacks. Lastly, HUMMUS reduced afternoon blood glucose concentrations by ∼5% compared with BARS (P < 0.05).

CONCLUSIONS

Acute consumption of a low-sugar, afternoon hummus snack improved diet quality and selected indices of appetite, satiety, and glycemic control in healthy adults. Long-term trials assessing the effects of hummus snacking on health outcomes are warranted.