Testing the causal relationship of fat and sugar intake with depression and cortisol: a Mendelian Randomisation study.

Unhealthy diets high in fat and sugar content may have an impact on psychological health and increase the risk of Major Depressive Disorder (MDD) and stress levels. On the other hand, MDD and stress might be related to food choices and intake. However, it is not clear whether diet, and specifically fat and sugar intake, is causally related to stress and MDD, and whether this relationship may be bi-directional. This study utilised Mendelian Randomisation (MR) to investigate the causal nature of the relationship of fat and sugar intake with MDD and cortisol (as a proxy of stress), and to shed light on the direction of this relationship. Summary-level data for all exposure and outcome variables were obtained from large-scale, non-overlapping GWASs in individuals of European ancestry. Bidirectional analyses were performed: one with macronutrients as exposures and one with MDD/cortisol as exposures. Random-effects inverse-variance weighted regression was used as the primary analytic method for genetic instruments with at least two single nucleotide polymorphisms (SNPs) available (and individual Wald ratio was used when only one SNP was available). Higher levels of genetically predicted relative sugar intake were causally associated with lower MDD risk, for both genome-wide significant p-value threshold of p < 1 × 10-8, (OR = 0.553, 95% CI: 0.395-0.775) and relaxed p-value threshold of p < 1 × 10-6 (OR = 0.786, 95% CI: 0.630-0.981). No reverse causality was detected in the opposite direction as MDD was not associated with sugar consumption. The associations observed for all the other pairs of variables were weak and imprecise. A number of limitations was present in the study, such as low-SNP based heritability for some exposures, inability to prove whether variants were correlated with unmeasured confounders and self-reporting of MDD data. Lifestyle and/or pharmacological interventions targeting sugar-related physiological mechanisms may help to reduce depressive symptoms. However, more research is necessary on short- and long-term effects of sugar on the risk of MDD. Additionally, future studies should investigate whether the amount and type of sugar consumed may underlie the impact of sugar on mood and stress levels.

The carbon isotope ratio of breath is elevated by short-term and long-term added sugar and animal protein intake in a controlled feeding study.

BACKGROUND: The breath carbon isotope ratio (CIR) was recently identified as a noninvasive candidate biomarker of short-term added sugars (AS) intake. OBJECTIVES: This study aimed to better understand the potential of the breath CIR as a dietary biomarker. We evaluated the effects of short-term and long-term intakes of AS, animal protein (AP), and related variables on breath CIR, in the context of typical dietary intake patterns. METHODS: We conducted a 15-d controlled feeding study of 100 adults (age 18-70 y, 55% females) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes and recorded the timing of food consumption. Three breath samples (fasting, midday, and evening) were collected on each of 3 nonconsecutive study days. We modeled the effects of dietary intake in each of 8 h preceding collection of the breath sample on breath CIR with a linear mixed model, which also included 15-d mean intakes, sex, age, and BMI. RESULTS: Median (IQR) intakes of AS and AP in our study were 65 (38) and 67 (33) g/d, respectively. Midday and evening breath CIRs correlated strongly with each other (0.80) and with fasting breath CIR (0.77 and 0.68, respectively). In our linear mixed models, breath CIR increased by AS consumed 1-4 h before sample collection, AP consumed 3-6 h before sample collection, and 15-d intakes of AS and AP, all with similar effect sizes. The breath CIR was also inversely associated with 15-d intakes of intrinsic sugars and plant protein; thus, associations with 15-d intakes were particularly strong when expressed proportionally as the AS ratio (added sugars/total sugars) and AP ratio (animal protein/total protein). CONCLUSIONS: The breath CIR is a promising measure of long-term intakes of AS and AP, especially as proportional intakes. Approaches to increase specificity would benefit the further development of this biomarker.

Is too much sugar bitter? The impacts of sugars on health.

This paper reviews the associations between sugars consumption and non-communicable diseases. Systematic reviews demonstrate associations between sugars intake and dental caries, weight gain, type 2 diabetes and cardiovascular diseases. Children consuming more sugar-sweetened beverages (SSBs) are 1.55 times more likely to be overweight. In adults, higher consumption of SSBs is associated with a 27% higher relative risk of developing type 2 diabetes. In adults, greater free sugar consumption was positively associated with total CVD (HR 1.07; 95% CI: 1.03-1.10), ischaemic heart disease (HR 1.06; 95%CI: 1.02,1.10), and stroke (HR 1.10, 95% CI: 1.04, 1.17). Those consuming sugars higher than the recommended level of 10% of total energy are more likely to develop dental caries; 42 out of 50 studies involving children and 5 out of 5 in adults reported at least one positive association between sugars and caries. Reduction in sugars consumption requires a myriad of interventions to reduce supply and demand at national and global levels, fiscal policies, alongside high-quality research and promoting environments to reduce the burden of NCDs.

The Carbon Isotope Ratio as an Objective Biomarker of Added Sugar Intake: A Scoping Review of Current Evidence in Human Nutrition.

Objective biomarkers of dietary intake are needed to advance nutrition research. The carbon isotope ratio (C13/C12; CIR) holds promise as an objective biomarker of added sugar (AS) and sugar-sweetened beverage (SSB) intake. This systematic scoping review presents the current evidence on CIRs from human studies. Search results (through April 12, 2024) yielded 6297 studies and 24 final articles. Studies were observational (n = 12), controlled feeding (n = 10), or dietary interventions (n = 2). CIRs were sampled from blood (n = 23), hair (n = 5), breath (n = 2), and/or adipose tissue (n = 1). Most (n = 17) conducted whole tissue (that is, bulk) analysis, 8 used compound specific isotope analysis (CSIA), and/or 2 studies used methods appropriate for analyzing breath. Studies were conducted in 3 concentrated geographic regions of the United States (n = 7 Virginia; n = 5 Arizona; n = 4 Alaska), with only 2 studies conducted in other countries. Studies that used CSIA to examine the CIR from the amino acid alanine (CIR-Ala; n = 4) and CIR analyzed from breath (n = 2) provided the most robust evidence for CIR as an objective biomarker of AS and SSBs (R2 range 0.36-0.91). Studies using bulk analysis of hair or blood showed positive, but modest and more variable associations with AS and SSBs (R2 range 0.05-0.48). Few studies showed no association, particularly in non-United States populations and those with low AS and SSB intakes. Two studies provided evidence for CIR to detect changes in SSB intake in response to dietary interventions. Overall, the most compelling evidence supports CIR-Ala as an objective indicator of AS intake and breath CIR as an indicator of short-term AS intake. Considering how to adjust for underlying dietary patterns remains an important area of future work and emerging methods using breath and CSIA warrant additional investigation. More evidence is needed to refine the utility and specificity of CIRs to measure AS and SSB intake.

Sugar assimilation underlying dietary evolution of Neotropical bats.

Dietary specializations in animals lead to adaptations in morphology, anatomy and physiology. Neotropical bats, with their high taxonomic and trophic diversity, offer a unique perspective on diet-driven evolutionary adaptations. Here we assess the metabolic response to different dietary sugars among wild-caught bats. We found that insectivorous bats had a pronounced metabolic response to trehalose, whereas bats with nectar and fruit-based diets showed significantly higher blood glucose levels in response to glucose and sucrose, reaching levels over 750 mg dl-1. The genomic analysis of 22 focal species and two outgroup species identified positive selection for the digestive enzyme trehalase in insect eaters, while sucrase-isomaltase showed selection in lineages with omnivorous and nectar diets. By examining anatomical and cellular features of the small intestine, we discovered that dietary sugar proportion strongly impacted numerous digestive traits, providing valuable insight into the physiological implications of molecular adaptations. Using hybridization chain reaction (HCR) RNA fluorescence in situ hybridization, we observed unusually high expression in the glucose transporter gene Slc2a2 in nectar bats, while fruit bats increased levels of Slc5a1 and Slc2a5. Overall, this study highlights the intricate interplay between molecular, morphological and physiological aspects of diet evolution, offering new insights into the mechanisms of dietary diversification and sugar assimilation in mammals.

High sugar diets can increase susceptibility to bacterial infection in Drosophila melanogaster.

Overnutrition with dietary sugar can worsen infection outcomes in diverse organisms including insects and humans, through generally unknown mechanisms. In the present study, we show that adult Drosophila melanogaster fed high-sugar diets became more susceptible to infection by the Gram-negative bacteria Providencia rettgeri and Serratia marcescens. We found that P. rettgeri and S. marcescens proliferate more rapidly in D. melanogaster fed a high-sugar diet, resulting in increased probability of host death. D. melanogaster become hyperglycemic on the high-sugar diet, and we find evidence that the extra carbon availability may promote S. marcescens growth within the host. However, we found no evidence that increased carbon availability directly supports greater P. rettgeri growth. D. melanogaster on both diets fully induce transcription of antimicrobial peptide (AMP) genes in response to infection, but D. melanogaster provided with high-sugar diets show reduced production of AMP protein. Thus, overnutrition with dietary sugar may impair host immunity at the level of AMP translation. Our results demonstrate that dietary sugar can shape infection dynamics by impacting both host and pathogen, depending on the nutritional requirements of the pathogen and by altering the physiological capacity of the host to sustain an immune response.

Influence of Exercise and Genistein to Mitigate the Deleterious Effects of High-Fat High-Sugar Diet on Alzheimer's Disease-Related Markers in Male Mice.

The prevalence of obesity and related consequences, including insulin resistance and Alzheimer's-like neuropathology, has increased dramatically. Contributing to this prevalence is the shift in lifestyle preference away from wholesome foods and exercise to the Western-style diet and sedentarism. Despite advances in drug development, a healthy diet and regular exercise remain the most effective approaches to mitigating the unwanted sequelae of diet-induced obesity on brain health. In this study, we used the high-fat high-sugar (HFHS) mouse model of neurodegeneration to examine the effects of exercise training (HFHS+Ex), genistein treatment (HFHS+Gen), and combination treatment (HFHS+Ex+Gen) on proteins relating to neurodegeneration in the brain of male mice. After a period of 12 weeks, as expected, HFHS feeding increased body weight, adipose tissue weight, and systemic plasma inflammation (TNF-α) compared to lean mice fed a standard diet. HFHS feeding also increased protein expression of brain markers of insulin resistance (pGSK-3ß, p-IR), apoptosis (caspase 3), early neurofibrillary tangles (CP13), and amyloid-beta precursor (CT20). Compared to HFHS mice, Ex decreased body weight, plasma TNF-α, and expression of pGSK-3ß, caspase 3, CP13, amyloid-ß precursor (22c11), and ADAM10. Treatment with Gen was equally protective on these markers and decreased the expression of p-IR. Combination treatment with Ex and Gen afforded the greatest overall benefits, and this group exhibited the greatest reduction in body and adipose tissue weight and all brain markers, except for 22c11 and ADAM10, which were decreased compared to mice fed an HFHS diet. In addition, levels of 4G8, which detects protein levels of amyloid-ß, were decreased with combination treatment. Our results indicate that exercise training, genistein supplementation, or combination treatment provide varying degrees of neuroprotection from HFHS feeding-induced Alzheimer's pathology. Future perspectives could include evaluating moderate exercise regimens in combination with dietary supplementation with genistein in humans to determine whether the same benefits translate clinically.

Associations of sugar-related food parenting practices and parental feeding styles with prospective dietary behavior of children and adolescents: a systematic review of the literature from 2017 to 2023.

Introduction: High consumption of sugar-rich foods and beverages has been associated with increased overweight and obesity in children and adolescents. Dietary behavior is influenced by learned mechanisms that originate in childhood and is associated with food parenting practices (FPP) and parental feeding styles (PFS). This systematic review aimed to narratively synthesize FPP and PFS concerning sugar-rich foods and beverages and their associations with the prospective dietary behavior of children and adolescents to derive evidence-based recommendations for health professionals and parents to promote healthy behaviors. Methods: A systematic literature search was conducted using PubMed and Web of Science databases covering the publication years 2017-2023. The results were narratively synthesized, and exposure-outcome matrices were used for visual representation. The review included 15 peer-reviewed studies from different geographical regions that investigated FPP or PFS regarding the handling of sugar-rich foods and beverages in children's diets and reported the associations with the prospective dietary behavior of children and adolescents. Results: The findings indicate that highly controlling parental practices were associated with the development of unhealthy eating behaviors and preferences for sugar-rich foods and beverages over time. Conversely, parental practices that emphasized structure and balance in dietary choices yielded more positive long-term outcomes, associated with reduced preferences for sugar-rich foods and drinks. Discussion: The results underscore the significance of fostering a healthy home environment and active parental role modeling in promoting healthier dietary behaviors among children and adolescents.

Dual Use of Cannabis with Tobacco Is Associated with Increased Sugary Food and Drink Intake in Young People.

Rates of cannabis initiation among teenagers and young adults are increasing. Further, the use of various forms of cannabis (smoked or vaped) with nicotine (dual use) is increasingly common among young people. The health effects of dual use are lesser known, particularly in the context of high-potency cannabis products and across different routes of administration, which is ominous in terms of predicting future health outcomes. There is a long history of cannabis use being associated with decreased activity and increased snacking, both of which could portend an increased risk of metabolic and cardiovascular disease, particularly when these habits begin during formative years. However, modern forms of cannabis may not have these same effects. Here, we assess whether cannabis use alone and dual use of cannabis with nicotine impact dietary and exercise habits in young people. An anonymous, social media-based survey was designed based on the UC San Diego Inhalant Questionnaire and published diet and exercise questionnaires. A total of 457 surveys were completed. Young sole cannabis users represented 29% of responders, 16% were dual users of cannabis and nicotine, and 55% were non-users of either drug. Although the sole use of cannabis was not associated with dietary or activity differences relative to non-users, dual users of cannabis and nicotine reported higher consumption of unhealthy sugars. This novel finding of dual use being associated with increased sugar intake in young people raises concerns for an increased risk of metabolic syndrome and cardiovascular disease in this population.

Identifying the Leading Sources of Saturated Fat and Added Sugar in U.S. Adults.

The 2020-2025 Dietary Guidelines for Americans recommend limiting intakes of saturated fat and added sugars (SF/AS) to <10% total energy. Data-driven approaches to identify sources of SF/AS are needed to meet these goals. We propose using a population-based approach to identify the leading food and beverage sources of SF/AS consumed by US adults. Foods and beverages reported as consumed were assessed from two, 24 h dietary recalls (24HRDR) from 36,378 adults aged 19 years and older from the 2005-2018 National Health and Nutrition Examination Survey. Intakes of SF/AS were aggregated across both 24HRDR to identify What We Eat in America food categories accounting for ≥90% of SF/AS, respectively, by the total population and within population subgroups. Data were weighted to estimate a nationally representative sample. Ninety-five discrete food categories accounted for ≥90% of the total SF/AS intakes for >88% of the representative sample of U.S. adults. The top sources of SF were cheese, pizza, ice cream, and eggs. The leading sources of AS were soft drinks, tea, fruit drinks, and cakes and pies. This analysis reflects a parsimonious approach to reliably identify foods and beverages that contribute to SF/AS intakes in U.S. adults.

A Preschool based intervention to reduce Early Childhood Caries in a District of Sri Lanka: A Quasi-experimental Study.

OBJECTIVE: Early Childhood Caries (ECC) is prevalent among preschool children. The aim was to assess the effectiveness of an intervention to modify family-level determinants of caries (i.e. maternal parenting style, oral health-related self-efficacy and oral health-related knowledge) via preschool teachers, to improve the child level determinants of ECC (dietary sugar consumption, oral hygiene pattern, dental attendance pattern). BASIC RESEARCH DESIGN: Quasi-experimental study. SETTING: Preschools in Gampaha District, Sri Lanka. PARTICIPANTS: Preschoolers and their mothers/caregivers. INTERVENTIONS: Delivered via preschool teachers to 200 children and their caregivers. MAIN OUTCOME MEASURES: Maternal parenting style, oral health related self-efficacy and oral health related knowledge, parentally reported dietary sugar consumption, oral hygiene pattern, dental attendance pattern and ECC. RESULTS: Maternal oral health related knowledge, authoritative parenting, authoritarian parenting and oral health related self-efficacy, maternally reported sugar consumption, sweetened drink consumption, tooth brushing frequency, dental visiting during the past six months and receipt of treatment better in the intervention group than the control group post-intervention. CONCLUSIONS: The intervention shows potential in modifying family level determinants of ECC.

Associations of sugar intake, high-sugar dietary pattern, and the risk of dementia: a prospective cohort study of 210,832 participants.

BACKGROUND: Limited evidence demonstrated the potential relationship between dietary sugar intake and dementia. This association demands further clarification in a large-scale population. METHODS: A total of 210,832 participants from the UK Biobank cohort were included in this prospective cohort study. Absolute and relative sugar intake and high-sugar dietary scores were utilized to reflect dietary sugar intake. Absolute sugar intake was identified by the Oxford WebQ in the UK Biobank. Relative sugar intake was calculated by dividing the absolute sugar intake by total diet energy. High-sugar dietary pattern was identified using the method of reduced rank regression. Cox proportional hazards regression analyses and restricted cubic splines were performed to examine the longitudinal associations between dietary sugar intake and all-cause dementia and its main subtype, Alzheimer's disease. Explorative mediation analyses were conducted to explore underlying mechanisms. RESULTS: Increased absolute sugar intake (g/day) was significantly associated with a higher risk of all-cause dementia (HR = 1.003, [95%CI: 1.002-1.004], p < 0.001) and Alzheimer's disease (1.002, [1.001-1.004], 0.005). Relative sugar intake (%g/kJ/day) also demonstrated significant associations with all-cause dementia (1.317, [1.173-1.480], p < 0.001) and Alzheimer's disease (1.249, [1.041-1.500], 0.017), while the high-sugar dietary score was only significantly associated with a higher risk of all-cause dementia (1.090, [1.045-1.136], p < 0.001). In addition, both sugar intake and high-sugar dietary score demonstrated significant non-linear relationships with all-cause dementia and Alzheimer's disease (all p values for non-linearity < 0.05). CONCLUSIONS: Our study provided evidence that excessive sugar intake was associated with dementia. Controlling the excess consumption of dietary sugar may be of great public health implications for preventing dementia.

The Effects of Long-Term High Fat and/or High Sugar Feeding on Sources of Postprandial Hepatic Glycogen and Triglyceride Synthesis in Mice.

BACKGROUND: In MASLD (formerly called NAFLD) mouse models, oversupply of dietary fat and sugar is more lipogenic than either nutrient alone. Fatty acids suppress de novo lipogenesis (DNL) from sugars, while DNL inhibits fatty acid oxidation. How such factors interact to impact hepatic triglyceride levels are incompletely understood. METHODS: Using deuterated water, we measured DNL in mice fed 18-weeks with standard chow (SC), SC supplemented with 55/45-fructose/glucose in the drinking water at 30% (w/v) (HS), high-fat chow (HF), and HF with HS supplementation (HFHS). Liver glycogen levels and its sources were also measured. For HS and HFHS mice, pentose phosphate (PP) fluxes and fructose contributions to DNL and glycogen were measured using [U-13C]fructose. RESULTS: The lipogenic diets caused significantly higher liver triglyceride levels compared to SC. DNL rates were suppressed in HF compared to SC and were partially restored in HFHS but supplied a minority of the additional triglyceride in HFHS compared to HF. Fructose contributed a significantly greater fraction of newly synthesized saturated fatty acids compared to oleic acid in both HS and HFHS. Glycogen levels were not different between diets, but significant differences in Direct and Indirect pathway contributions to glycogen synthesis were found. PP fluxes were similar in HS and HFHS mice and were insufficient to account for DNL reducing equivalents. CONCLUSIONS: Despite amplifying the lipogenic effects of fat, the fact that sugar-activated DNL per se barely contributes suggests that its role is likely more relevant in the inhibition of fatty acid oxidation. Fructose promotes lipogenesis of saturated over unsaturated fatty acids and contributes to maintenance of glycogen levels. PP fluxes associated with sugar conversion to fat account for a minor fraction of DNL reducing equivalents.

Essential Nutrients, Added Sugar Intake, and Epigenetic Age in Midlife Black and White Women: NIMHD Social Epigenomics Program.

Importance: Nutritive compounds play critical roles in DNA replication, maintenance, and repair, and also serve as antioxidant and anti-inflammatory agents. Sufficient dietary intakes support genomic stability and preserve health. Objective: To investigate the associations of dietary patterns, including intakes of essential nutrients and added sugar, and diet quality scores of established and new nutrient indices with epigenetic age in a diverse cohort of Black and White women at midlife. Design, Setting, and Participants: This cross-sectional study included analyses (2021-2023) of past women participants of the 1987-1997 National Heart, Lung, and Blood Institute Growth and Health Study (NGHS), which examined cardiovascular health in a community cohort of Black and White females aged between 9 and 19 years. Of these participants who were recruited between 2015 and 2019 from NGHS's California site, 342 females had valid completed diet and epigenetic assessments. The data were analyzed from October 2021 to November 2023. Exposure: Diet quality scores of established nutrient indices (Alternate Mediterranean Diet [aMED], Alternate Healthy Eating Index [AHEI]-2010); scores for a novel, a priori-developed Epigenetic Nutrient Index [ENI]; and mean added sugar intake amounts were derived from 3-day food records. Main Outcomes and Measures: GrimAge2, a second-generation epigenetic clock marker, was calculated from salivary DNA. Hypotheses were formulated after data collection. Healthier diet indicators were hypothesized to be associated with younger epigenetic age. Results: A total of 342 women composed the analytic sample (mean [SD] age, 39.2 [1.1] years; 171 [50.0%] Black and 171 [50.0%] White participants). In fully adjusted models, aMED (ß, -0.41; 95% CI, -0.69 to -0.13), AHEI-2010 (ß, -0.05; 95% CI, -0.08 to -0.01), and ENI (ß, -0.17; 95% CI, -0.29 to -0.06) scores, and added sugar intake (ß, 0.02; 95% CI, 0.01-0.04) were each significantly associated with GrimAge2 in expected directions. In combined analyses, the aforementioned results with GrimAge2 were preserved with the association estimates for aMED and added sugar intake retaining their statistical significance. Conclusions and Relevance: In this cross-sectional study, independent associations were observed for both healthy diet and added sugar intake with epigenetic age. To our knowledge, these are among the first findings to demonstrate associations between added sugar intake and epigenetic aging using second-generation epigenetic clocks and one of the first to extend analyses to a diverse population of Black and White women at midlife. Promoting diets aligned with chronic disease prevention recommendations and replete with antioxidant or anti-inflammatory and pro-epigenetic health nutrients while emphasizing low added sugar consumption may support slower cellular aging relative to chronological age, although longitudinal analyses are needed.

Estimated changes in free sugar consumption one year after the UK soft drinks industry levy came into force: controlled interrupted time series analysis of the National Diet and Nutrition Survey (2011-2019).

BACKGROUND: The UK soft drinks industry levy (SDIL) was announced in March 2016 and implemented in April 2018, encouraging manufacturers to reduce the sugar content of soft drinks. This is the first study to investigate changes in individual-level consumption of free sugars in relation to the SDIL. METHODS: We used controlled interrupted time series (2011-2019) to explore changes in the consumption of free sugars in the whole diet and from soft drinks alone 11 months after SDIL implementation in a nationally representative sample of adults (>18 years; n=7999) and children (1.5-19 years; n=7656) drawn from the UK National Diet and Nutrition Survey. Estimates were based on differences between observed data and a counterfactual scenario of no SDIL announcement/implementation. Models included protein consumption (control) and accounted for autocorrelation. RESULTS: Accounting for trends prior to the SDIL announcement, there were absolute reductions in the daily consumption of free sugars from the whole diet in children and adults of 4.8 g (95% CI 0.6 to 9.1) and 10.9 g (95% CI 7.8 to 13.9), respectively. Comparable reductions in free sugar consumption from drinks alone were 3.0 g (95% CI 0.1 to 5.8) and 5.2 g (95% CI 4.2 to 6.1). The percentage of total dietary energy from free sugars declined over the study period but was not significantly different from the counterfactual. CONCLUSION: The SDIL led to significant reductions in dietary free sugar consumption in children and adults. Energy from free sugar as a percentage of total energy did not change relative to the counterfactual, which could be due to simultaneous reductions in total energy intake associated with reductions in dietary free sugar.

Behavioral tests of the insulin-cholinergic-dopamine link in nucleus accumbens and inhibition by high fat-high sugar diet in male and female rats.

It was previously shown in striatal slices obtained from male rats that insulin excites cholinergic interneurons and increases dopamine (DA) release via α4ß2 nicotinic receptors on DA terminals. The effect of insulin on DA release was blocked either by maintaining rats on a high sugar-high fat (HS-HF) diet that induced hyperinsulinemia and nucleus accumbens (NAc) insulin receptor insensitivity, or applying the α4ß2 antagonist DHßE. In vivo, NAc shell insulin inactivation decreased a glucose lick microstructure parameter indicative of hedonic impact in male and female rats, and prevented flavor-nutrient learning, tested only in males. The HS-HF diet decreased hedonic impact in males but not females, and prevented flavor-nutrient learning, tested only in males. The present study extends testing to more fully assess the translation of brain slice results to the behaving rat. Insulin inactivation by antibody microinjection in NAc shell was found to decrease the number of lick bursts emitted and average lick burst size, measures of incentive motivation and hedonic impact respectively, for a wide range of glucose concentrations in male and female rats. In contrast, the HS-HF diet decreased these lick parameters in males but not females. Follow-up two-bottle choice tests for 10 % versus 40 % glucose showed decreased intake of both concentrations by males but increased intake of 40 % glucose by females. In a further set of experiments, it was predicted that α4ß2 receptor blockade would induce the same behavioral effects as insulin inactivation. In females, DHßE microinjection in NAc shell decreased both lick parameters for glucose as predicted, but in males only the number of lick bursts emitted was decreased. DHßE also decreased the number of lick bursts emitted for saccharin by females but not males. Finally, DHßE microinjection in NAc shell decreased flavor-nutrient learning in both sexes. The few discrepancies seen with regard to the hypothesized insulin-nicotinic-dopaminergic regulation of behavioral responses to nutritive sweetener, and its inhibition by HS-HF diet, are discussed with reference to sex differences in DA dynamics, female resistance to diet-induced metabolic morbidities, and extra-striatal cholinergic inputs to NAc.

Associations between Intake of Dietary Sugars and Diet Quality: A Systematic Review of Recent Literature.

Understanding the relationship between the intake of sugars and diet quality can inform public health recommendations. This systematic review synthesized recent literature on associations between sugar intake and diet quality in generally healthy populations aged 2 years or older. We searched databases from 2010 to 2022 for studies of any design examining associations between quantified sugar intake in the daily diet and dietary indexes (DIs) or micronutrient intakes. Different sugar types and diet quality measures were analyzed separately. We converted DI results to Pearson's r correlations and grouped indexes with or without a free or added sugar component to facilitate cross-study comparisons. Meta-analysis was deemed inappropriate. From 13,869 screened records, we included 27 cross-sectional studies. NUQUEST risk of bias ratings were neutral (n = 18 studies) or poor (n = 9), and strength of evidence by the GRADE approach was very low due to study design. Most studies reported negative associations for added and free sugars with diet quality indexes (r ranging from -0.13 to -0.42) and nutrients of public health concern (fiber, vitamin D, calcium, potassium), while associations with total sugars were mixed. Due to cross-sectional study designs, the clinical relevance of these findings is unclear. Prospective studies are needed to minimize confounding and inform causal relationships.

Exploring parental secretive eating of sugary foods and drinks, and its associations with food consumption in families.

As a way of modeling healthier eating habits for their children, parents may intentionally avoid consuming sugary foods and drinks (SFDs) in their presence but consume these on other occasions (later referred to as parental secretive eating). This study aimed to 1) explore the prevalence of parental secretive eating, 2) investigate the associations between parental secretive eating and SFD consumption in parents and children, and 3) qualitatively explore the reasons for parental secretive eating. Participants were Finnish mothers (n = 362), fathers (n = 123), and their 3-6-year-old children (n = 403); this data was collected in 2017 as part of the baseline assessment of the DAGIS intervention. Parents reported how often they avoided eating SFDs in the presence of their child, completed food frequency questionnaires for themselves and their child, and responded to an open-ended question of explaining reasons for secretive eating. The overall prevalence of parental secretive eating was 68%. It was more common among mothers than fathers (p < 0.001) and most prevalent in chocolate (61%) and sweets (59%). Parental secretive eating was positively associated with SFD consumption both among mothers (ꞵ = 0.274, p < 0.001) and fathers (ꞵ = 0.210, p = 0.028) in linear regression models adjusted for parents' and child's age, child's gender, parental education level, and number of household members. Mothers' or fathers' secretive eating and child's SFD consumption were not associated (ꞵ = 0.031, p = 0.562; ꞵ = -0.143; p = 0.167). Three themes describing reasons for parental secretive eating were found: family food rules, avoiding child's requests, and aspiration for healthy modeling. In conclusion, parental secretive eating may play an important role in determining SFD consumption in families with preschoolers. Additional research is needed to determine whether parents can prevent their own eating habits from influencing their child through secretive eating.

Impact of nutrient warning labels on Colombian consumers' selection and identification of food and drinks high in sugar, sodium, and saturated fat: A randomized controlled trial.

OBJECTIVE: This study assessed the impact of nutrient warnings on product selection and ability to identify food products high in nutrients of concern in Colombia. METHODS: In an online experiment (May-June 2023), Colombian adults were randomized to a nutrient warning, guideline daily amounts (GDA), Nutri-Score, or no-label condition (n = 8,004). Participants completed selection tasks between two fruit drinks labeled according to their condition, one high in sugar and one not. Next, participants answered questions about products high in sugar, sodium, and/or saturated fat ("high-in" product). Finally, they selected which label would most discourage them from consuming a high-in product. RESULTS: Fewer participants (17%) exposed to the nutrient warning indicated they would purchase the high-sugar fruit drink compared to Nutri-Score (27%, Holm-adjusted (adj) p<0.001) and no label conditions (31%, adj p<0.001); there were no differences between the nutrient warning and GDA label (14%, adj p = 0.087). Compared to the nutrient warning, the GDA label was slightly more effective at helping consumers identify which drink was high in sugar (89% versus 92%, adj p<0.001), while the Nutri-Score and no-label conditions were less effective. Compared to all other conditions, nutrient warnings were more effective at helping participants identify that products were high in nutrients of concern, were more effective at decreasing intentions to purchase these high-in products and were perceived as more effective. Nutrient warnings were most often selected as the label that most discouraged consumption. CONCLUSIONS: Nutrient warnings are a promising policy to help consumers identify and discourage consumption of products high in nutrients of concern. TRIAL REGISTRATION: Trial Registration: NCT05783726.