Core body temperature, energy expenditure, and epinephrine during fasting, eucaloric feeding, and overfeeding in healthy adult men: evidence for a ceiling effect for human thermogenic response to diet.

Background: In homeothermic animals, approximately 50% of daily energy expenditure (EE) is spent to maintain a consistent core body temperature (CBT). In humans, little is known about CBT responses to feeding and overfeeding and their relationship to diet-related changes in EE.

Objective: To study the effects of feeding and overfeeding on CBT and its association with diet-induced thermogenesis (DIT).

Cognitive dietary restraint, disinhibition, and hunger are associated with 24-h energy expenditure.

Background: Higher energy expenditure (EE) is associated with greater food intake, possibly because the human body senses EE and modifies eating behaviors to regulate food intake and ultimately achieve energy balance. As eating behaviors are also influenced by social and cultural factors, any association between EE and eating behavior may differ between ethnicities and sexes.

Objective: To assess relationships between EE and eating behavior constructs of the Three-Factor Eating Questionnaire (TFEQ).

Norepinephrine and T4 Are Predictors of Fat Mass Gain in Humans With Cold-Induced Brown Adipose Tissue Activation.

Context: In healthy adults with detectable cold-induced brown adipose tissue activation (CIBA), the relationships between sympathetic nervous system (SNS) or thyroid activity during energy balance (EBL) with CIBA and body composition change are undetermined.

Objective: To investigate the relationships between CIBA and thermoneutral catecholamines and thyroid hormones measured during EBL and to determine if CIBA, catecholamines, or thyroid hormones predict body composition changes.

Design, Setting, Participants, And Interventions: Twelve healthy volunteers (seven male and five female) with positive CIBA [>2 standardized uptake value (g/mL)] had 24-hour energy expenditure (24hEE) assessed during EBL via whole-room indirect calorimetry while residing on a clinical research unit.

Exenatide has a pronounced effect on energy intake but not energy expenditure in non-diabetic subjects with obesity: A randomized, double-blind, placebo-controlled trial.

Aims: Exenatide is a glucagon-like peptide 1 (GLP-1) mimetic which induces weight loss predominantly, it is presumed, via decreased food intake. However, circulating GLP-1 is also a determinant of energy expenditure. We sought to quantify the effect of exenatide on energy expenditure (EE) and energy intake.

Cycling Efficiency During Incremental Cycle Ergometry After 24 Hours of Overfeeding or Fasting.

Objective: The objective of this study was to determine whether net cycling efficiency (NET) is altered by 24-hour fasting or overfeeding and whether it correlates with dietary-related energy expenditure (EE) and future weight change.

Methods: In a crossover design, healthy subjects fasted or were overfed for 24 hours while in a whole-room calorimeter using five diets with doubled energy needs: standard, high-carbohydrate (75%), high-fat (60%), high-protein (30%), and low-protein (3%) diets. Graded cycling exercise at low power outputs (10-25-50 W) was performed the day before and after each dietary intervention.

Energy Expenditure and Hormone Responses in Humans After Overeating High-Fructose Corn Syrup Versus Whole-Wheat Foods.

Objective: This study sought to understand how the dietary source of carbohydrates, either high-fructose corn syrup (HFCS) or complex carbohydrates, affects energy expenditure (EE) measures, appetitive sensations, and hormones during 24 hours of overfeeding.

Methods: Seventeen healthy participants with normal glucose regulation had 24-hour EE measures and fasting blood and 24-hour urine collection during four different 1-day diets, including an energy-balanced diet, fasting, and two 75% carbohydrate diets (5% fat) given at 200% of energy requirements with either HFCS or whole-wheat foods as the carbohydrate source. In eight volunteers, hunger was assessed with visual analog scales the morning after the diets.

Early results of a surgeon-led, perioperative surgical home.

Background: The Perioperative Surgical Home is a novel care model designed to provide patient-centered, high-quality surgical care. In 2013, we implemented POSH, a pilot Peri-Operative Surgical Home at Phoenix Indian Medical Center (PIMC), an Indian Health Service hospital, as a quality improvement project. After 2 y, we sought to quantify the impact of POSH on the quality of surgical care at PIMC.

The Consistency in Macronutrient Oxidation and the Role for Epinephrine in the Response to Fasting and Overfeeding.

Context: In humans, dietary vs intraindividual determinants of macronutrient oxidation preference and the role of the sympathetic nervous system (SNS) during short-term overfeeding and fasting are unclear.

Objective: To understand the influence on metabolic changes of diet and SNS during 24 hours of overfeeding.

Design, Setting, Participants, And Interventions: While residing on a clinical research unit, 64 participants with normal glucose regulation were assessed during energy balance, fasting, and four 24-hour overfeeding diets, given in random order.

Non-hematopoietic effects of endogenous erythropoietin on lean mass and body weight regulation.

Objective: To investigate the concurrent relationships between human plasma erythropoietin concentrations and energy expenditure (EE), body composition, plasma leptin concentrations, and associations with weight change.

Methods: Plasma to measure erythropoietin and leptin; data for body composition; 24-h EE measured in a whole-room calorimeter; and 75 g oral glucose tolerance testing were available from 109 full-heritage Pima Indians (55% male) from a larger study designed to understand the causes of obesity. Seventy-nine subjects had data for weight at a later visit (mean follow-up = 4.

Perceived stress and anhedonia predict short-and long-term weight change, respectively, in healthy adults.

Objective: Perceived stress; emotional eating; anhedonia; depression and dietary restraint, hunger, and disinhibition have been studied as risk factors for obesity. However, the majority of studies have been cross-sectional and the directionality of these relationships remains unclear. In this longitudinal study, we assess their impact on future weight change.

T-cell receptor repertoire variation may be associated with type 2 diabetes mellitus in humans.

Background: Recent work in Pima Indians, a population with high rates of obesity and type 2 diabetes mellitus (T2DM), demonstrated that human leukocyte antigen haplotype DRB1*02 carriers have an increased acute insulin response and decreased risk for the development of T2DM, implicating loss of self-tolerance in the pathogenesis of T2DM. Advances in genomic sequencing have made T-cell receptor repertoire analysis a practical mode of investigation.

Methods: High-throughput sequencing of T-cell receptor complementarity-determining region 3 was carried out in male Pima Indians with normal glucose regulation (n = 11; age = 31 ± 8 years; %fat = 30.

The effect of differing patterns of childhood body mass index gain on adult physiology in American Indians.

Objective: Identifying groups of individuals with similar patterns of body mass index (BMI) change during childhood may increase understanding of the relationship between childhood BMI and adult health.

Methods: Discrete classes of BMI z-score change were determined in 1,920 American Indian children with at least four non diabetic health examinations between the ages of 2 and 18 years using latent class trajectory analysis. In subsets of subjects, data were available for melanocortin-4 receptor (MC4R) sequencing; in utero exposure to type 2 diabetes (T2D); or, as adults, oral glucose tolerance tests, onset of T2D, or body composition.

Energy Expenditure Responses to Fasting and Overfeeding Identify Phenotypes Associated With Weight Change.

Because it is unknown whether 24-h energy expenditure (EE) responses to dietary extremes will identify phenotypes associated with weight regulation, the aim of this study was to determine whether such responses to fasting or overfeeding are associated with future weight change. The 24-h EE during energy balance, fasting, and four different overfeeding diets with 200% energy requirements was measured in a metabolic chamber in 37 subjects with normal glucose regulation while they resided on our clinical research unit. Diets were given for 24 h each and included the following: (1) low protein (3%), (2) standard (50% carbohydrate, 20% protein), (3) high fat (60%), and (4) high carbohydrate (75%).

Higher Daily Energy Expenditure and Respiratory Quotient, Rather Than Fat-Free Mass, Independently Determine Greater ad Libitum Overeating.

Context: Body fat-free mass (FFM), energy expenditure (EE), and respiratory quotient (RQ) are known predictors of daily food intake. Because FFM largely determines EE, it is unclear whether body composition per se or the underlying metabolism drives dietary intake.

Objective: The objective of the study was to test whether 24-hour measures of EE and RQ and their components influence ad libitum food intake independently of FFM.

A Human Thrifty Phenotype Associated With Less Weight Loss During Caloric Restriction.

Successful weight loss is variable for reasons not fully elucidated. Whether effective weight loss results from smaller reductions in energy expenditure during caloric restriction is not known. We analyzed whether obese individuals with a "thrifty" phenotype, that is, greater reductions in 24-h energy expenditure during fasting and smaller increases with overfeeding, lose less weight during caloric restriction than those with a "spendthrift" phenotype.

Increased 24-hour ad libitum food intake is associated with lower plasma irisin concentrations the following morning in adult humans.

Background: The relationship between food intake and irisin concentrations in humans is unclear.

Objectives: To determine whether the previous day's intake impacts fasting plasma irisin concentrations, or whether fasting irisin concentrations associate with subsequent ad libitum food intake.

Methods: Sixty-six nondiabetic adults (42 men) were admitted for a study of the determinants of energy intake.

Fasting hyperglycemia predicts lower rates of weight gain by increased energy expenditure and fat oxidation rate.

Context: Increased adiposity and insulin resistance are associated with hyperglycemia and previous studies have reported that higher glucoses are associated with lower rates of weight gain. One possible mechanism is via increased energy expenditure (EE).

Objective: To assess the relationships between changes in EE during spontaneous weight gain and concomitant changes in glucose levels.

Weight maintenance from young adult weight predicts better health outcomes.

Objective: Defining groups of individuals within a larger population with similar patterns of weight change over time may provide insight into influences of weight stability or gain.

Methods: Latent class growth modeling was used to define subgroups of weight change in adult members of the Gila River Indian Community participating in at least four non-diabetic health exams including OGTTs (N = 1,157, 762F/395M; 78.4 ± 19.

Common genetic variation in and near the melanocortin 4 receptor gene (MC4R) is associated with body mass index in American Indian adults and children.

Six rare functional coding mutations were previously identified in melanocortin 4 receptor (MC4R) in 6,760 American Indians. Individuals heterozygous for one of these mutations become obese while young. We now investigate whether common non-coding variation near MC4R also contributes to obesity.

Perseveration augments the effects of cognitive restraint on ad libitum food intake in adults seeking weight loss.

As executive function may influence eating behaviors, our aim was to determine whether measures of executive function predict ad libitum food intake in subjects seeking weight loss. 78 obese, healthy individuals (40 female/38 male; age 36 ± 10 y; BMI 37.8 ± 7.

Common genetic variation in the glucokinase gene (GCK) is associated with type 2 diabetes and rates of carbohydrate oxidation and energy expenditure.

Aims/hypothesis: Glucokinase (GCK) plays a role in glucose metabolism and glucose-stimulated insulin secretion. Rare mutations in GCK cause MODY. We investigated whether common variation (minor allele frequency ≥0.

Soda consumption during ad libitum food intake predicts weight change.

Soda consumption may contribute to weight gain over time. Objective data were used to determine whether soda consumption predicts weight gain or changes in glucose regulation over time. Subjects without diabetes (128 men, 75 women; mean age 34.

Overfeeding over 24 hours does not activate brown adipose tissue in humans.

Context: Human brown adipose tissue (BAT) is activated with cold exposure, but it is unknown whether overfeeding activates BAT.

Objective: We determined BAT activation with cold, fasting, and overfeeding and the relationship of BAT activation with future weight change.

Design, Setting, Participants, And Interventions: Sixteen healthy adults were evaluated during energy balance, fasting, and 24 hours of 200% overfeeding.

Lower "awake and fed thermogenesis" predicts future weight gain in subjects with abdominal adiposity.

Awake and fed thermogenesis (AFT) is the energy expenditure (EE) of the nonactive fed condition above the minimum metabolic requirement during sleep and is composed of the thermic effect of food and the cost of being awake. AFT was estimated from whole-room 24-h EE measures in 509 healthy subjects (368 Native Americans and 141 whites) while subjects consumed a eucaloric diet. Follow-up data were available for 290 Native Americans (median follow-up time: 6.

Extent and determinants of thermogenic responses to 24 hours of fasting, energy balance, and five different overfeeding diets in humans.

Context: Individual variation in the ability to convert excess calories to heat and the effects of dietary macronutrient composition are unclear.

Objective: Stability and determinants of the energy expenditure (EE) response to overconsumption were assessed.

Design, Setting, And Participants: Twenty subjects (75% male) with normal glucose regulation were evaluated during 24 hours each of energy balance, fasting, and 5 different diets with 200% energy requirements in a clinical research unit.