Characterization of adults concerning the use of a hypothetical mHealth application addressing stress-overeating: an online survey.

BACKGROUND: About 40% of people respond to stress by consuming more unhealthy foods. This behavior is associated with increased energy intake and the risk of obesity. As mobile health (mHealth) applications (apps) have been shown to be an easy-to-use intervention tool, the characterization of potential app users is necessary to develop target group-specific apps and to increase adherence rates. METHODS: This cross-sectional online survey was conducted in the spring of 2021 in Germany. Sociodemographic data and data on personality (Big Five Inventory, BFI-10), stress-eating (Salzburg Stress Eating Scale, SSES), and technology behavior (Personal Innovativeness in the Domain of Information Technology, PIIT; Technology Acceptance Model 3, TAM 3) were collected. RESULTS: The analysis included 1228 participants (80.6% female, mean age: 31.4 ± 12.8 years, mean body mass index (BMI): 23.4 ± 4.3 kg/m2). Based on the TAM score, 33.3% (409/1228) of the participants had a high intention to use a hypothetical mHealth app to avoid stress-overeating. These persons are characterized by a higher BMI (24.02 ± 4.47 kg/m2, p < 0.001), by being stress-overeaters (217/409, 53.1%), by the personality trait "neuroticism" (p < 0.001), by having specific eating reasons (all p < 0.01), and by showing a higher willingness to adopt new technologies (p < 0.001). CONCLUSION: This study suggests that individuals who are prone to stress-overeating are highly interested in adopting an mHealth app as support. Participants with a high intention to use an mHealth app seem to have a general affinity towards new technology (PIIT) and appear to be more insecure with conflicting motives regarding their diet. TRIAL REGISTRATION: This survey was registered in the German Clinical Trials Register (Registration number: DRKS00023984).

Phenotypic variation in biting behavior associated with differences in expression of olfactory genes in the vector mosquito, Aedes albopictus (Diptera: Culicidae).

We evaluated miRNA and mRNA expression differences in head tissues between avid-biting vs. reluctant-biting Aedes albopictus (Skuse) females from a single population over a 20-min timescale. We found no differences in miRNA expression between avid vs. reluctant biters, indicating that translational modulation of blood-feeding behavior occurs on a longer timescale than mRNA transcription. In contrast, we detected 19 differentially expressed mRNAs. Of the 19 differentially expressed genes at the mRNA level between avid-biting vs. reluctant-biting A. albopictus, 9 are implicated in olfaction, consistent with the well-documented role of olfaction in mosquito host-seeking. Additionally, several of the genes that we identified as differentially expressed in association with phenotypic variation in biting behavior share similar functions with or are inferred orthologues of, genes associated with evolutionary variation in biting behaviors of Wyeomyia smithii (Coq.) and Culex pipiens (Lin.). A future goal is to determine whether these genes are involved in the evolutionary transition from a biting to a non-biting life history.

Efficacy of an app-based multimodal lifestyle intervention on body weight in persons with obesity: results from a randomized controlled trial.

BACKGROUND: Despite an increasing number of smartphone applications (apps) addressing weight management, data on the effect of app-based multimodal obesity treatment approaches on weight loss is limited. This study aimed to examine the effect of a digital multimodal weight loss intervention program delivered by an app on body weight in persons with obesity. METHODS: For this single-centre randomized controlled study, 168 adults with a body mass index (BMI) between 30.0 and 40.0 kg/m2 without severe comorbidities were recruited in the region of Munich and randomized into two intervention groups. The ADHOC group received an app-based multimodal weight loss program from baseline on for 12 weeks plus 12 weeks of follow-up. The EXPECT group received the app-based intervention for 12 weeks after 12 weeks of "waiting" (no intervention). Anthropometric data, data on quality of life (EuroQol, EQ-5D-5L), and app usage data were collected. RESULTS: 64.3% of study participants were women, mean age was 46.8 ± 11.0 years, and mean BMI was 34.2 ± 2.8 kg/m2. The completers analysis resulted in a weight loss of 3.2 ± 3.2 kg (3.2 ± 3.0%) in the ADHOC group and 0.4 ± 2.6 kg (0.3 ± 2.6%) in the EXPECT group after 12 weeks, with a significant difference between the groups (ß [95% CI] = -2.9 [-3.8; -1.9], p < 0.001). Completers in the ADHOC group showed weight maintenance after 24 weeks. The time spent on the app was associated with weight reduction (ß [95% CI] = -0.10 [-0.18; -0.01], p = 0.03). CONCLUSIONS: Application of a multimodal app-based weight loss program results in moderate weight loss in persons with obesity. TRIAL REGISTRATION: This study was registered in the German Clinical Trials Register (Registration number: DRKS00025291).

MicroRNA Expression Prior to Biting in a Vector Mosquito Anticipates Physiological Processes Related to Energy Utilization, Reproduction and Immunity.

Understanding the molecular and physiological processes underlying biting behavior in vector mosquitoes has important implications for developing novel strategies to suppress disease transmission. Here, we conduct small-RNA sequencing and qRT-PCR to identify differentially expressed microRNAs (miRNAs) in the head tissues of two subspecies of Culex pipiens that differ in biting behavior and the ability to produce eggs without blood feeding. We identified eight differentially expressed miRNAs between biting C. pipiens pipiens (Pipiens) and non-biting C. pipiens molestus (Molestus); six of these miRNAs have validated functions or predicted targets related to energy utilization (miR8-5-p, miR-283, miR-2952-3p, miR-1891), reproduction (miR-1891), and immunity (miR-2934-3p, miR-92a, miR8-5-p). Although miRNAs regulating physiological processes associated with blood feeding have previously been shown to be differentially expressed in response to a blood meal, our results are the first to demonstrate differential miRNA expression in anticipation of a blood meal before blood is actually imbibed. We compare our current miRNA results to three previous studies of differential messenger RNA expression in the head tissues of mosquitoes. Taken together, the combined results consistently show that biting mosquitoes commit to specific physiological processes in anticipation of a blood meal, while non-biting mosquitoes mitigate these anticipatory costs.

Automated segmentation of the human supraclavicular fat depot via deep neural network in water-fat separated magnetic resonance images.

Background: Human brown adipose tissue (BAT), mostly located in the cervical/supraclavicular region, is a promising target in obesity treatment. Magnetic resonance imaging (MRI) allows for mapping the fat content quantitatively. However, due to the complex heterogeneous distribution of BAT, it has been difficult to establish a standardized segmentation routine based on magnetic resonance (MR) images. Here, we suggest using a multi-modal deep neural network to detect the supraclavicular fat pocket. Methods: A total of 50 healthy subjects [median age/body mass index (BMI) =36 years/24.3 kg/m2] underwent MRI scans of the neck region on a 3 T Ingenia scanner (Philips Healthcare, Best, Netherlands). Manual segmentations following fixed rules for anatomical borders were used as ground truth labels. A deep learning-based method (termed as BAT-Net) was proposed for the segmentation of BAT on MRI scans. It jointly leveraged two-dimensional (2D) and three-dimensional (3D) convolutional neural network (CNN) architectures to efficiently encode the multi-modal and 3D context information from multi-modal MRI scans of the supraclavicular region. We compared the performance of BAT-Net to that of 2D U-Net and 3D U-Net. For 2D U-Net, we analyzed the performance difference of implementing 2D U-Net in three different planes, denoted as 2D U-Net (axial), 2D U-Net (coronal), and 2D U-Net (sagittal). Results: The proposed model achieved an average dice similarity coefficient (DSC) of 0.878 with a standard deviation of 0.020. The volume segmented by the network was smaller compared to the ground truth labels by 9.20 mL on average with a mean absolute increase in proton density fat fraction (PDFF) inside the segmented regions of 1.19 percentage points. The BAT-Net outperformed all implemented 2D U-Nets and the 3D U-Nets with average DSC enhancement ranging from 0.016 to 0.023. Conclusions: The current work integrates a deep neural network-based segmentation into the automated segmentation of supraclavicular fat depot for quantitative evaluation of BAT. Experiments show that the presented multi-modal method benefits from leveraging both 2D and 3D CNN architecture and outperforms the independent use of 2D or 3D networks. Deep learning-based segmentation methods show potential towards a fully automated segmentation of the supraclavicular fat depot.

Clock-talk: have we forgotten about geographic variation?

Wyeomyia smithii, the pitcher-plant mosquito, has evolved from south to north and from low to high elevations in eastern North America. Along this seasonal gradient, critical photoperiod has increased while apparent involvement of the circadian clock has declined in concert with the evolutionary divergence of populations. Response to classical experiments used to test for a circadian basis of photoperiodism varies as much within and among populations of W. smithii as have been found in the majority of all other insects and mites. The micro-evolutionary processes revealed within and among populations of W. smithii, programmed by a complex underlying genetic architecture, illustrate a gateway to the macro-evolutionary divergence of biological timing among species and higher taxa in general.

Digital communication and virtual reality for extending the behavioural treatment of obesity - the patients' perspective: results of an online survey in Germany.

BACKGROUND: CBT has been found effective for the treatment of EDs and obesity. However not all patients achieve clinically significant weight loss and weight regain is common. In this context, technology-based interventions can be used to enhance traditional CBT but are not yet widespread. This survey therefore explores the status quo of pathways of communication between patients and therapists, the use of digital applications for therapy as well as attitudes towards VR from the perspective of patients with obesity in Germany. METHODS: This cross-sectional online survey was conducted in October 2020. Participants were recruited digitally through social media, obesity associations and self-help groups. The standardized questionnaire included items concerning current treatment, paths of communication with their therapists, and attitudes toward VR. The descriptive analyses were performed with Stata. RESULTS: The 152 participants were mostly female (90%), had a mean age of 46.5 years (SD = 9.2) and an average BMI of 43.0 kg/m² (SD = 8.4). Face-to-face communication with their therapist was considered of high importance in current treatment (M = 4.30; SD = 0.86) and messenger apps were the most frequently used digital application for communication. Participants were mostly neutral regarding the inclusion of VR methods in obesity treatment (M = 3.27; SD = 1.19). Only one participant had already used VR glasses as part of treatment. Participants considered VR suitable for exercises promoting body image change (M = 3.40; SD = 1.02). DISCUSSION: Technological approaches in obesity therapy are not widespread. Face-to-face communication remains the most important setting for treatment. Participants had low familiarity with VR but a neutral to positive attitude toward the technology. Further studies are needed to provide a clearer picture of potential treatment barriers or educational needs and to facilitate the transfer of developed VR systems into clinical practice.

CBT is the treatment of choice for a variety of psychological disorders, among them eating disorders and obesity. However not all patients benefit equally and weight-regain is frequent. Technology-based approaches like virtual reality can enhance traditional CBT, but they are not yet used very often in clinical practice. This study asked patients with obesity which digital methods of communication and treatment were part of their obesity therapy and whether they would welcome VR approaches in their therapy. 152 patients participated and reported a face-to-face communication with their therapist to be of high importance. Messenger apps (e.g. WhatsApp) were the most commonly used digital methods of communication. VR applications or wearables do not play a role in the respondents' therapy. Participants were mostly neutral toward VR technology but expressed positive expectations toward VR as part of body image therapy.

Association between Genotype and the Glycemic Response to an Oral Glucose Tolerance Test: A Systematic Review.

The inter-individual variability of metabolic response to foods may be partly due to genetic variation. This systematic review aims to assess the associations between genetic variants and glucose response to an oral glucose tolerance test (OGTT). Three databases (PubMed, Web of Science, Embase) were searched for keywords in the field of genetics, OGTT, and metabolic response (PROSPERO: CRD42021231203). Inclusion criteria were available data on single nucleotide polymorphisms (SNPs) and glucose area under the curve (gAUC) in a healthy study cohort. In total, 33,219 records were identified, of which 139 reports met the inclusion criteria. This narrative synthesis focused on 49 reports describing gene loci for which several reports were available. An association between SNPs and the gAUC was described for 13 gene loci with 53 different SNPs. Three gene loci were mostly investigated: transcription factor 7 like 2 (TCF7L2), peroxisome proliferator-activated receptor gamma (PPARγ), and potassium inwardly rectifying channel subfamily J member 11 (KCNJ11). In most reports, the associations were not significant or single findings were not replicated. No robust evidence for an association between SNPs and gAUC after an OGTT in healthy persons was found across the identified studies. Future studies should investigate the effect of polygenic risk scores on postprandial glucose levels.

Changes in Lifestyle and Body Weight in Children and Adolescents during the COVID-19 Pandemic: A Representative Survey of Parents in Germany.

INTRODUCTION: The public restrictions taken during the COVID-19 pandemic have substantially affected lifestyle and health behavior of children and adolescents. In Germany, little is known how these changes influenced daily life in families with children and adolescents. METHODS: A cross-sectional survey was performed in April/May 2022 across Germany, similar to a survey performed in 2020. Parents (N = 1,004, 20-65 years) with at least one child aged 3-17 years filled in an online questionnaire released by the Forsa Institute for Social Research and Statistical Analysis. Fifteen questions related to eating habits, dietary patterns, physical activity, media consumption, fitness, mental health, and body weight were included, and standard socioeconomic parameters were assessed. RESULTS: Parents' answers indicated that there was a parental self-reported weight gain in every sixth child since the beginning of the COVID-19 pandemic. This was most obvious in children from families with lower household income and preexisting overweight. Parents also reported that lifestyle patterns had worsened: 70% reported an increase of media consumption during leisure time, 44% a decrease in daily physical activity, and 16% the worsening of dietary habits (e.g., 27% stated to eat more cake and sweets). Children aged 10-12 years were most severely affected. CONCLUSION: Negative health effects related to the COVID-19 pandemic are predominantly observed in children 10-12 years of age and in children from families with low household income, suggesting a worsening social disparity. Political action is urgently needed to tackle the adverse consequences of the COVID-19 pandemic on childhood lifestyle and health.

Latent Genetic Effects of Past Selection on Blood Feeding: History Matters.

Conventional wisdom is that selection decreases genetic variation in populations, variation that should enable and be essential for population persistence in an ever-changing world. Basically, we find the opposite. Response to selection on biting in the pitcher-plant mosquito, Wyeomyia smithii, increases from 20 to 80% in 19 generations, but reverts back to the original 20% after seven generations of relaxed (not reversed) selection. At the same time, biting in the control line remains at the original 20% through 30 generations without blood feeding. Imposition of selection on biting in both lines elicits a rapid response in the previously selected line, but, importantly, not in the control line. Genetic variation for biting has increased, not decreased, as a consequence of long-term directional selection, contrary to expectations. Convergent phenotypes belie the underlying difference in future adaptive potential. Selection events over time in the background of individuals or populations will determine outcomes of applied research, be it in the fields of medicine, agriculture, or conservation. In short, history matters.

Associations of Texture Features of Proton Density Fat Fraction Maps between Lumbar Vertebral Bone Marrow and Paraspinal Musculature.

Chemical shift encoding-based water−fat MRI (CSE-MRI)-derived proton density fat fraction (PDFF) has been used for non-invasive assessment of regional body fat distributions. More recently, texture analysis (TA) has been proposed to reveal even more detailed information about the vertebral or muscular composition beyond PDFF. The aim of this study was to investigate associations between vertebral bone marrow and paraspinal muscle texture features derived from CSE-MRI-based PDFF maps in a cohort of healthy subjects. In this study, 44 healthy subjects (13 males, 55 ± 30 years; 31 females, 39 ± 17 years) underwent 3T MRI including a six-echo three-dimensional (3D) spoiled gradient echo sequence used for CSE-MRI at the lumbar spine and the paraspinal musculature. The erector spinae muscles (ES), the psoas muscles (PS), and the vertebral bodies L1-4 (LS) were manually segmented. Mean PDFF values and texture features were extracted for each compartment. Features were compared between males and females using logistic regression analysis adjusted for age and body mass index (BMI). All texture features of ES except for Sum Average were significantly (p < 0.05) different between men and women. The three global texture features (Variance, Skewness, Kurtosis) for PS as well as LS showed a significant difference between male and female subjects (p < 0.05). Mean PDFF measured in PS and ES was significantly higher in females, but no difference was found for the vertebral bone marrow's PDFF. Partial correlation analysis between the texture features of the spine and the paraspinal muscles revealed a highly significant correlation for Variance(global) (r = 0.61 for ES, r = 0.62 for PS; p < 0.001 respectively). Texture analysis using PDFF maps based on CSE-MRI revealed differences between healthy male and female subjects. Global texture features in the lumbar vertebral bone marrow allowed for differentiation between men and women, when the overall PDFF was not significantly different, indicating that PDFF maps may contain detailed and subtle textural information beyond fat fraction. The observed significant correlation of Variance(global) suggests a metabolic interrelationship between vertebral bone marrow and the paraspinal muscles.

Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention.

Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.

Genetics and Epigenetics in Personalized Nutrition: Evidence, Expectations, and Experiences.

With the presentation of the blueprint of the first human genome in 2001 and the advent of technologies for high-throughput genetic analysis, personalized nutrition (PN) becomes a new scientific field and the first commercial offerings of genotype-based nutrition advice emerge at the same time. Here, the state of evidence for the effect of genetic and epigenetic factors in the development of obesity, the metabolic syndrome, and resulting illnesses such as non-insulin-dependent diabetes mellitus and cardiovascular diseases is summarized. This study also critically value the concepts of PN that are built around the new genetic avenue from both the academic and a commercial perspective and their effectiveness in causing sustained changes in diet, lifestyle, and for improving health. Despite almost 20 years of research and commercial direct-to-consumer offerings, evidence for the success of gene-based dietary recommendations is still generally lacking. This calls for new concepts of future PN solutions that incorporate more phenotypic measures and provide a panel of instruments (e.g., self- and bio-monitoring tools, feedback systems, algorithms based on artificial intelligence) that increases compliance based on the individual´s physical and social environment and value system.

Carbohydrate intake - current knowledge on weight management.

PURPOSE OF REVIEW: Carbohydrates are the main contributor to daily energy intake and, thus, might play an essential role in the development and treatment of obesity. This nonsystematic literature overview summarized current knowledge about the association between carbohydrate intake (quantity and quality) and weight management. RECENT FINDINGS: There is scientific evidence for the association between the quality of carbohydrates and body weight or metabolic parameters (e.g. fasting glucose). Thus, dietary intake of high-quality carbohydrates should be preferred over food with a low carbohydrate quality. In contrast, heterogeneous data are available for the association between the amount of carbohydrate intake and anthropometric parameters (e.g. body weight, body fat). Regulation of dietary intake and body weight is complex. For instance, gene-diet interactions might play a role in carbohydrate intake and metabolism. SUMMARY: There is evidence for the association between intake of high-quality carbohydrates and body weight. However, for the treatment of obesity, a negative energy balance is crucial. The success in weight loss was independent of the quantity and quality of carbohydrate intake. To sum up, recently published literature does not change the current opinion about carbohydrate intake and obesity.

Association between Habitual Diet and the Postprandial Glucose Response-An Enable Study.

SCOPE: It is inconclusive which factors influence inter-individual variations of postprandial glucose response (PPGR). This study investigates whether the habitual diet is associated with PPGR. METHODS AND RESULTS: Data from healthy adults (young adults with 18-25 years, middle-aged adults with 40-65 years, and older adults with 75-85 years) is collected at baseline and during an oral glucose tolerance test (OGTT) collected. Habitual diet is assessed by a food frequency questionnaire and two 24-h food lists. Associations between habitual diet and glucose incremental area under the curve (iAUCmin ) are examined by regression models. The intake of cereals and cereal products is negatively associated with glucose iAUCmin (p = 0.002) in the total cohort (N = 459, 50% women, 55 ± 21 years, BMI 26 ± 5 kg m- 2 ). Up to 9% of the variance in the glycemic response is explained by the respective dietary parameters identified in the models of the specific age groups. CONCLUSION: There are age-specific diet-related effects on PPGR. The usual intake of cereals and cereal products seems to play a greater role in PPGR in more than one age group. Further research is needed, to establish how diet can be optimized based on age and PPGR.

Intraindividual difference between supraclavicular and subcutaneous proton density fat fraction is associated with cold-induced thermogenesis.

Background: Brown adipose tissue (BAT) activity is triggered by cold exposure resulting in an increased resting energy expenditure, called cold-induced non-shivering thermogenesis (CIT). Magnetic resonance (MR)-based proton density fat fraction (PDFF) of the supraclavicular fossa has been proposed as a surrogate marker of human BAT. The present study investigates supraclavicular PDFF in relation to CIT. Methods: For this prospective cross-sectional study 39 adults were recruited, from a cross-sectional study, exploring energy expenditure after cold exposure compared to thermoneutral conditions. Participants underwent additional MR examination of neck, pelvis, and abdomen. Supraclavicular and subcutaneous gluteal adipose tissue depots were segmented semi-automatically. Mean PDFF was assessed for each compartment and the delta PDFF was calculated as the difference of both. Correlation analysis of supraclavicular PDFF to CIT was performed for the whole cohort and subgroups, sorted by body mass index (BMI) and body fat percentage. Results: Median age of participants (61.5% female) was 27 years. BMI ranged from 19.0 to 38.5 kg/m2, with body fat percentages from 4.6% to 45.3%. Median supraclavicular PDFF of 82.5% and median gluteal PDFF of 91.1%, were significantly different (P<0.0001). Median delta PDFF was 8.8% (3.9-21.9%). Mean CIT was 4.7%±9.0%. No statistically significant correlation of supraclavicular PDFF and CIT was found in the whole cohort and in most of the observed subgroups. Just the subgroup with normal body fat percentage revealed significant correlations between supraclavicular PDFF and CIT (rho =-0.59; P=0.003). Delta PDFF was significantly associated with CIT (rho =0.36; P=0.026). Conclusions: PDFF is influenced by adiposity. Therefore, if supraclavicular PDFF is used as approach to indirectly assess BAT presence, body composition should be considered. Delta PDFF, as the difference between gluteal and supraclavicular PDFF, may be a marker of CIT.

Attitude of Nutrition Experts Toward Psychotherapy and Virtual Reality as Part of Obesity Treatment-An Online Survey.

Background: The management of obesity requires lifestyle-based interventions covering nutrition, physical activity, and behavior. As part of cognitive behavioral therapy (CBT), body image therapy approaches can be used not only by psychotherapists. One tool to conduct behavioral therapy is virtual reality (VR). It is unknown, whether nutrition experts conduct behavioral therapy, and whether they would like to use VR technology as a tool to conduct body image therapy as part of obesity management. Objective: This survey aimed to collect data from nutrition experts treating people with obesity about the status quo regarding behavioral and body image therapy as part of obesity management, and regarding their attitude toward VR in obesity therapy. Methods: The survey was conducted online in autumn 2020. Participants were recruited digitally through expert and professional associations. The standardized questionnaire included items concerning sociodemographic, professional status, behavioral therapy, body image, and VR. The descriptive analysis was performed with Excel, the subgroup analyses with R. Results: Data from 158 nutrition experts was analyzed. Participants were mostly female (98/102, 96.1%) and had a mean age of 45.6 ± 11.3 years (n = 101). Most of the survey participants (93/124, 75.0%) stated to use behavioral treatment methods in case of weight reduction as the primary target. More than half of the participants stated to address body image (99/150, 66.0%). Almost all (111/112, 99.1%) nutrition experts have never used VR-glasses. The suitability and importance of VR technology as part of obesity therapy was estimated as neutral by around 50%. Overall, no statistically significant difference could be shown between age groups regarding attitudes toward VR in obesity treatment. Conclusion: The results of this non-representative survey indicate that nutrition experts do not use VR technology in nutrition counseling sessions to treat obesity. In addition, survey participants have a positive attitude to VR technology, whereas they are not familiar with this technology. In future, VR technology might support nutrition experts of every age using elements of body image therapy. Survey Registration: The German Register of Clinical Studies (Registration Number: DRKS00022853).

Conserved molecular pathways underlying biting in two divergent mosquito genera.

Mosquitoes transmit a wide variety of devastating pathogens when they bite vertebrate hosts and feed on their blood. However, three entire mosquito genera and many individual species in other genera have evolved a nonbiting life history in which blood is not required to produce eggs. Our long-term goal is to develop novel interventions that reduce or eliminate the biting behavior in vector mosquitoes. A previous study used biting and nonbiting populations of a nonvector mosquito, Wyeomyia smithii, as a model to uncover the transcriptional basis of the evolutionary transition from a biting to a nonbiting life history. Herein, we ask whether the molecular pathways that were differentially expressed due to differences in biting behavior in W. smithii are also differentially expressed between subspecies of Culex pipiens that are obligate biting (Culex pipiens pipiens) and facultatively nonbiting (Culex pipiens molestus). Results from RNAseq of adult heads show dramatic upregulation of transcripts in the ribosomal protein pathway in biting C. pipiens, recapitulating the results in W. smithii, and implicating the ancient and highly conserved ribosome as the intersection to understanding the evolutionary and physiological basis of blood feeding in mosquitoes. Biting Culex also strongly upregulate energy production pathways, including oxidative phosphorylation and the citric acid (TCA) cycle relative to nonbiters, a distinction that was not observed in W. smithii. Amino acid metabolism pathways were enriched for differentially expressed genes in biting versus nonbiting Culex. Relative to biters, nonbiting Culex upregulated sugar metabolism and transcripts contributing to reproductive allocation (vitellogenin and cathepsins). These results provide a foundation for developing strategies to determine the natural evolutionary transition between a biting and nonbiting life history in vector mosquitoes.