BACKGROUND: The differential effects of pecans versus other popular snack foods on appetite and blood markers of metabolism and satiety have not been well studied. This study investigated the effects of a single mid-morning snack of pecans or tortilla chips on subjective appetite, food intake, blood measures of hormones and metabolites, and resting energy expenditure.
METHODS: Twenty participants with overweight and obesity were enrolled in a within-participants, randomized crossover trial. Participants had indwelling catheters placed for blood sampling and were fed a standardized breakfast, followed two hours later by a 250 kcal snack of either pecans or tortilla chips, and then by a self-selected lunch. Visual analog scale (VAS) appetite measures, blood markers, and energy expenditure were taken at intervals after food consumption.
RESULTS: VAS ratings, energy, food intake and macronutrient composition did not differ between treatment conditions, but glucose and insulin were significantly more elevated after tortilla chips. Free fatty acids (FFA), triglycerides (TG), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) were higher after consuming pecans compared to tortilla chips.
CONCLUSIONS: Pecan consumption improves postprandial glucose and insulin profiles which would be beneficial to individuals at risk of developing type 2 diabetes. Further studies are needed to investigate whether increased relative secretion of PYY and GLP-1 after eating pecans versus tortilla chips may affect subjective appetite and energy intake if consumed chronically.

Undernutrition (UN) increases child vulnerability to illness and mortality. Caused by a low amount and/or poor quality of food intake, it impacts physical, cognitive, and social development. Modern types of food consumption have given highly processed food a higher cultural value compared to minimally processed food.
OBJECTIVE: The objective of this study was to evaluate the effect on growth, metabolism, physical activity (PA), memory, inflammation, and toxicity of an enriched black corn chip (BC) made with endemic ingredients on post-weaned UN mice.
METHODS: A chip was made with a mixture of black corn, fava beans, amaranth, and nopal cactus. To probe the effects of UN, UN was induced in 3wo post-weaned male C57Bl/6j mice through a low-protein diet (LPD-50% of the regular requirement of protein) for 3w. Then, the BC was introduced to the animals\' diet (17%) for 5w; murinometric parameters were measured, as were postprandial glucose response, PA, and short-term memory. Histological analysis was conducted on the liver and kidneys to measure toxicity. Gene expression related to energy balance, thermogenesis, and inflammation was measured in adipose and hypothalamic tissues.
RESULTS: Treatment with the BC significantly improved mouse growth, even with a low protein intake, as evidenced by a significant increase in body weight, tail length, cerebral growth, memory improvement, physical activation, normalized energy expenditure (thermogenesis), and orexigenic peptides (AGRP and NPY). It decreased anorexigenic peptides (POMC), and there was no tissue toxicity.
CONCLUSIONS: BC treatment, even with persistent low protein intake, is a promising strategy against UN, as it showed efficacy in correcting growth deficiency, cognitive impairment, and metabolic problems linked to treatment by adjusting energy expenditure, which led to the promotion of energy intake and regulation of thermogenesis, all by using low-cost, accessible, and endemic ingredients.

BACKGROUND: Polycystic ovary syndrome (PCOS), the most common endocrine disorder in premenopausal women, is associated with increased obesity, hyperandrogenism, and altered brown adipose tissue (BAT) thermogenesis. MicroRNAs play critical functions in brown adipocyte differentiation and maintenance. We aim to study the role of microRNA-21 (miR-21) in altered energy homeostasis and BAT thermogenesis in a PCOS mouse model of peripubertal androgen exposure.
METHODS: Three-week-old miR-21 knockout (miR21KO) or wild-type (WT) female mice were treated with dihydrotestosterone (DHT) or vehicle for 90 days. Body composition was determined by EchoMRI. Energy expenditure (EE), oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory exchange ratio (RER) were measured by indirect calorimetry. Androgen receptor (AR), and markers of adipogenesis, de novo lipogenesis, angiogenesis, extracellular matrix remodeling, and thermogenesis were quantified by RT-qPCR and/or Western-blot.
RESULTS: MiR-21 ablation attenuated DHT-mediated increase in body weight while having no effect on fat or BAT mass. MiR-21 ablation attenuated DHT-mediated BAT AR upregulation. MiR-21 ablation did not alter EE; however, miR21KO DHT-treated mice have reduced VO2, VCO2, and RER. MiR-21 ablation reversed DHT-mediated decrease in food intake and increase in sleep time. MiR-21 ablation decreased some adipogenesis (Adipoq, Pparγ, and Cebpβ) and extracellular matrix remodeling (Mmp-9 and Timp-1) markers expression in DHT-treated mice. MiR-21 ablation abolished DHT-mediated increases in thermogenesis markers Cpt1a and Cpt1b, while decreasing CIDE-A expression.
CONCLUSIONS: Our findings suggest that BAT miR-21 may play a role in regulating DHT-mediated thermogenic dysfunction in PCOS. Modulation of BAT miR-21 levels could be a novel therapeutic approach for the treatment of PCOS-associated metabolic derangements.
Polycystic ovary syndrome (PCOS) is a common hormone disorder in premenopausal women, often linked to obesity and abnormal brown fat tissue activity. Women with PCOS have elevated male hormones, which are responsible for many metabolic problems. Our study focuses on understanding the role of microRNA-21 (miR-21) in the energy balance and brown fat tissue activity in a PCOS mouse model. We studied female mice with and without miR-21, treating them with a male hormone. We measured body composition and energy expenditure. We also analyzed the levels of specific genes and proteins related to fat tissue and energy production. Our findings showed that mice lacking miR-21 had less weight gain in response to male hormones, without fat or brown fat tissue mass changes. They also had reduced energy production, changed eating habits, and altered expression of genes related to fat tissue and energy production. In conclusion, our study suggests that miR-21 in brown fat tissue may regulate the energy imbalance caused by male hormones in PCOS. Adjusting miR-21 levels in brown fat tissue could be a new way to address the metabolic issues associated with PCOS.

UNASSIGNED: Estrogen deficiency is associated with unfavorable changes in body composition and metabolic health. While physical activity ameliorates several of the negative effects, loss of ovarian function is associated with decreased physical activity levels. It has been proposed that the changes in brain neurochemical levels and /or impaired skeletal muscle function may underlie this phenomenon.
UNASSIGNED: We studied the effect of estrogen deficiency induced via ovariectomy (OVX) in female Wistar rats (n = 64). Rats underwent either sham or OVX surgery and were allocated thereafter into four groups matched for body mass and maximal running capacity: sham/control, sham/max, OVX/control, and OVX/max, of which the max groups had maximal running test before euthanasia to induce acute response to exercise. Metabolism, spontaneous activity, and maximal running capacity were measured before (PRE) and after (POST) the surgeries. Three months following the surgery, rats were euthanized, and blood and tissue samples harvested. Proteins were analyzed from gastrocnemius muscle and retroperitoneal adipose tissue via Western blot. Brain neurochemical markers were measured from nucleus accumbens (NA) and hippocampus (HC) using ultra-high performance liquid chromatography.
UNASSIGNED: OVX had lower basal energy expenditure and higher body mass and retroperitoneal adipose tissue mass compared with sham group (p ≤ 0.005). OVX reduced maximal running capacity by 17% (p = 0.005) with no changes in muscle mass or phosphorylated form of regulatory light chain (pRLC) in gastrocnemius muscle. OVX was associated with lower serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) level in the NA compared with sham (p = 0.007). In response to acute exercise, OVX was associated with low serotonin level in the HC and high level in the NA (p ≤ 0.024).
UNASSIGNED: Our results highlight that OVX reduces maximal running capacity and affects the response of brain neurochemical levels to acute exercise in a brain region-specific manner. These results may offer mechanistic insight into why OVX reduces willingness to exercise.

Understanding how animals meet their daily energy requirements is critical in our rapidly changing world. Small organisms with high metabolic rates can conserve stored energy when food availability is low or increase energy intake when energetic requirements are high, but how they balance this in the wild remains largely unknown. Using miniaturized heart rate transmitters, we continuously quantified energy expenditure, torpor use and foraging behaviour of free-ranging male bats (Nyctalus noctula) in spring and summer. In spring, bats used torpor extensively, characterized by lowered heart rates and consequently low energy expenditures. In contrast, in summer, bats consistently avoided torpor, even though they could have used this low-energy mode. As a consequence, daytime heart rates in summer were three times as high compared with the heart rates in spring. Daily energy use increased by 42% during summer, despite lower thermogenesis costs at higher ambient temperatures. Likely, as a consequence, bats nearly doubled their foraging duration. Overall, our results indicate that summer torpor avoidance, beneficial for sperm production and self-maintenance, comes with a high energetic cost. The ability to identify and monitor such vulnerable energetic life-history stages is particularly important to predict how species will deal with increasing temperatures and changes in their resource landscapes.

Wearable devices such as the ActiGraph are now commonly used in research to monitor or track physical activity. This trend corresponds with the growing need to assess the relationships between physical activity and health outcomes, such as obesity, accurately. Device-based physical activity measures are best treated as functions when assessing their associations with scalar-valued outcomes such as body mass index. Scalar-on-function regression (SoFR) is a suitable regression model in this setting. Most estimation approaches in SoFR assume that the measurement error in functional covariates is white noise. Violating this assumption can lead to underestimating model parameters. There are limited approaches to correcting measurement errors for frequentist methods and none for Bayesian methods in this area. We present a non-parametric Bayesian measurement error-corrected SoFR model that relaxes all the constraining assumptions often involved with these models. Our estimation relies on an instrumental variable allowing a time-varying biasing factor, a significant departure from the current generalized method of moment (GMM) approach. Our proposed method also permits model-based grouping of the functional covariate following measurement error correction. This grouping of the measurement error-corrected functional covariate allows additional ease of interpretation of how the different groups differ. Our method is easy to implement, and we demonstrate its finite sample properties in extensive simulations. Finally, we applied our method to data from the National Health and Examination Survey to assess the relationship between wearable device-based measures of physical activity and body mass index in adults in the United States.

BACKGROUND: Obesity prevalence in youth with spina bifida is higher than in their typically developing peers. Obesity is associated with lifelong medical, psychological, and economic burdens. Successful prevention or treatment of obesity in individuals with spina bifida is compromised by (1) the lack of valid and reliable methods to identify body fat in a clinical setting and (2) limited data on energy expenditure that are necessary to provide daily caloric recommendations.
OBJECTIVE: The objectives of this study will be to develop 2 algorithms for use in youth with spina bifida in a clinical setting, one to model body fat and one to predict total daily energy expenditure. In addition, physical activity and dietary intake will be described for the sample.
METHODS: This multisite, prospective, national clinical study will enroll 232 youth with myelomeningocele aged 5 to 18 years (stratified by age and mobility). Participants will be enrolled for 1 week. Data obtained include 4 measures of body composition, up to 5 height measures, a ramped activity protocol, and a nutrition and physical activity screener. Participants will wear an accelerometer for the week. On the final study day, 2 samples of urine or saliva, which complete the doubly labeled water protocol, will be obtained. The analysis will include descriptive statistics, Bland-Altman plots, concordance correlation, and regression analysis.
RESULTS: The study received extramural federal funding in July 2019. Data collection was initiated in March 2020. As of April 2024, a total of 143 (female participants: n=76, 53.1%; male participants: n=67, 46.9%) out of 232 participants have been enrolled. Data collection is expected to continue throughout 2024. A no-cost extension until November 2025 will be requested for data analysis and dissemination of findings.
CONCLUSIONS: This study furthers previous pilot work that confirmed the acceptability and feasibility of obtaining alternate height, body composition, and energy expenditure measures. The findings from this study will enhance screening, prevention, and treatment of abnormal weight status by facilitating the accurate identification of youths\' weight status category and recommendations of daily caloric needs for this population that is at higher risk of obesity. Furthermore, the findings have the potential to impact outcomes for youth diagnosed with disabilities other than spina bifida who experience similar challenges related to alterations in body composition or fat distribution or measurement challenges secondary to mobility issues or musculoskeletal problems.
UNASSIGNED: DERR1-10.2196/52779.

Methylphenidate (MPH) has been previously shown to increase resting energy expenditure (REE) in individuals of normal weight; however, the effects on individuals living with obesity are currently unknown. Ten individuals living with obesity were randomly assigned to undergo 60 days of MPH administration with a daily dose of 0.5 mg/kg body weight or a placebo control. REE was measured before and after the 60-day intervention. There was a trend toward significance for group × time interaction on REE (p = 0.082) with a large effect size (η2 = 0.331), with MPH administration increasing REE compared to a decrease in placebo control. Preliminary findings from this pilot study show that MPH has the potential to counter the adaptive thermogenic process commonly seen in weight loss. This is a unique finding among pharmacotherapies, as no approved obesity drugs measurably impact REE.

Adults with intellectual disabilities experience numerous health inequalities. Targeting unhealthy lifestyle behaviours, such as high levels of sedentary behaviour and overweight/obesity, is a priority area for improving the health and adults with intellectual disabilities and reducing inequalities. Energy expenditure is a fundamental component of numerous health behaviours and an essential component of various free-living behaviour measurements, e.g. accelerometry. However, little is known about energy expenditure in adults with intellectual disabilities and no population-specific accelerometer data interpretation methods have been calibrated. The limited research in this area suggests that adults with intellectual disabilities have a higher energy expenditure, which requires further exploration, and could have significant impacts of device calibration. However, due to the complex methods required for measuring energy expenditure, it is essential to first evaluate feasibility and develop an effective protocol. This study aims to test the feasibility of a laboratory-based protocol to enable the measurement of energy expenditure and accelerometer calibration in adults with intellectual disabilities.We aimed to recruit ten adults (≥ 18 years) with intellectual disabilities. The protocol involved a total of nine sedentary, stationary, and physical activities, e.g. sitting, lying down, standing, and treadmill walking. Each activity was for 5 min, with one 10 min lying down activity to measure resting energy expenditure. Breath by breath respiratory gas exchange and accelerometry (ActiGraph and ActivPAL) were measured during each activity. Feasibility was assessed descriptively using recruitment and outcome measurement completion rates, and participant/stakeholder feedback.Ten adults (N = 7 female) with intellectual disabilities participated in this study. The recruitment rate was 50% and 90% completed the protocol and all outcome measures. Therefore, the recruitment strategy and protocol are feasible.This study addresses a significant gap in our knowledge relating to exercise laboratory-based research for adults with intellectual disabilities The findings from this study provide essential data that can be used to inform the development of future protocols to measure energy expenditure and for accelerometer calibration in adults with intellectual disabilities.

UNASSIGNED: Traditional yoga texts describe \"cross nostril breathing,\" with inhalation and exhalation through different nostrils. Previous research reported no clear differences in oxygen consumption during uninostril breathing (i.e., inhalation and exhalation through the same nostril), hence not supporting right and left uninostril breathing as activating or relaxing, respectively, with no research on oxygen consumed in \"cross nostril breathing.\"
UNASSIGNED: Oxygen consumed during \"cross nostril breathing\" was measured in healthy participants (n = 47, males, 26.3 ± 6.4 years). Five sessions (viz., right nostril inspiration yoga breathing [RNIYB], left nostril inspiration yoga breathing [LNIYB], alternate nostril yoga breathing [ANYB], breath awareness (BAW), and quiet rest (QR) were conducted on separate days in random order. Sessions were 33 min in duration with pre, during, and post states.
UNASSIGNED: Volume of oxygen consumed (VO2) and carbon dioxide eliminated (VCO2) increased during RNIYB (9.60% in VO2 and 23.52% in VCO2), LNIYB (9.42% in VO2 and 21.20% in VCO2) and ANYB (10.25% in VO2 and 22.72% in VCO2) with no significant change in BAW and QR. Diastolic blood pressure decreased during BAW and QR and after all five sessions (P < 0.05; in all cases). All comparisons were with the respective preceding state.
UNASSIGNED: During the three yoga breathing practices, the volume of oxygen consumed increased irrespective of the nostril breathed through, possibly associated with (i) conscious regulation of the breath; (ii) attention directed to the breath, and (iii) \"respiration-locked cortical activation.\" Restriction of the study to males reduces the generalizability of the findings.