The use of accelerometers to improve estimation of the thermic effect of food in whole room calorimetry studies.

We tested whether spontaneous physical activity (SPA) from accelerometers could be used in a whole room calorimeter to estimate thermic effect of food (TEF). Eleven healthy participants ( = 7 females; age: 27 ± 4 yr; body mass index: 22.8 ± 2.

The effects of early time restricted eating plus daily caloric restriction compared to daily caloric restriction alone on continuous glucose levels.

Background: The median eating duration in the U.S. is 14.

A Naturalistic Actigraphic Assessment of Changes in Adolescent Sleep, Light Exposure, and Activity Before and During COVID-19.

The majority of high school-aged adolescents obtain less than the recommended amount of sleep per night, in part because of imposed early school start times. Utilizing a naturalistic design, the present study evaluated changes in objective measurements of sleep, light, and physical activity before (baseline) and during the first wave of the COVID-19 pandemic (during COVID-19) in a group of US adolescents. Sixteen adolescents (aged 15.

Early time-restricted eating compared with daily caloric restriction: A randomized trial in adults with obesity.

Objective: This trial aimed to evaluate the acceptability and efficacy of early time-restricted eating plus daily caloric restriction (E-TRE+DCR) compared with DCR alone within a behavioral weight-loss intervention.

Methods: Participants (n = 81, 69 women, mean [SD] age: 38.0 [7.

Bone Turnover Markers After Six Nights of Insufficient Sleep and Subsequent Recovery Sleep in Healthy Men.

Purpose: The goal of this study was to determine the bone turnover marker (BTM) response to insufficient and subsequent recovery sleep, independent of changes in posture, body weight, and physical activity.

Methods: Healthy men (N = 12) who habitually slept 7-9 h/night were admitted to an inpatient sleep laboratory for a baseline 8 h/night sleep opportunity followed by six nights of insufficient sleep (5 h/night). Diet, physical activity, and posture were controlled.

The effects of the COVID-19 pandemic on weight loss in participants in a behavioral weight-loss intervention.

Objective: This study aimed to assess the effects of the COVID-19 pandemic on weight loss, physical activity, and sleep in adults with overweight or obesity participating in a 39-week weight-loss intervention.

Methods: Participants (n = 81, 85% female, mean [SD] age 38.0 [7.

Examining the Role of Exercise Timing in Weight Management: A Review.

Many adults cite exercise as a primary strategy for losing weight, yet exercise alone is modestly effective for weight loss and results in variable weight loss responses. It is possible that some of the variability in weight loss may be explained by the time of day that exercise is performed. Few studies have directly compared the effects of exercise performed at different times of the day (i.

Later Meal and Sleep Timing Predicts Higher Percent Body Fat.

Accumulating evidence suggests that later timing of energy intake (EI) is associated with increased risk of obesity. In this study, 83 individuals with overweight and obesity underwent assessment of a 7-day period of data collection, including measures of body weight and body composition (DXA) and 24-h measures of EI (photographic food records), sleep (actigraphy), and physical activity (PA, activity monitors) for 7 days. Relationships between body mass index (BMI) and percent body fat (DXA) with meal timing, sleep, and PA were examined.

Circadian Rhythm of Substrate Oxidation and Hormonal Regulators of Energy Balance.

Objective: The circadian system provides an organism with the ability to anticipate daily food availability and appropriately coordinate metabolic responses. Few studies have simultaneously assessed factors involved in both the anticipation of energy availability (i.e.

Appetite-Related Responses to Overfeeding and Longitudinal Weight Change in Obesity-Prone and Obesity-Resistant Adults.

Objective: Appetite responses to 3 days of overfeeding (OF) were examined as correlates of longitudinal weight change in adults classified as obesity prone (OP) or obesity resistant (OR).

Methods: OP (n = 22) and OR (n = 30) adults consumed a controlled eucaloric and OF diet (140% of energy needs) for 3 days, followed by 3 days of ad libitum feeding. Hunger and satiety were evaluated by visual analog scales.

Effect of frequent interruptions of sedentary time on nutrient metabolism in sedentary overweight male and female adults.

This study compared 24-h nutrient oxidation responses between a sedentary condition (SED) and a condition in which short 5-min bouts of moderate-intensity physical activity were performed hourly for nine consecutive hours over 4 days (MICRO). To determine whether any shifts in fuel use were due solely to increases in energy expenditure, we also studied a condition consisting of a single isoenergetic 45-min bout of moderate-intensity exercise (ONE). Twenty sedentary overweight or obese adults (10 men/10 women; 32.

Associations Among Dietary Fat Oxidation Responses to Overfeeding and Weight Gain in Obesity-Prone and Resistant Adults.

Objective: This study tested the hypothesis that 3 days of overfeeding (OF) decreases dietary fat oxidation and predicts longitudinal weight change in adults classified as obesity prone (OP) and obesity resistant (OR) based on self-identification and personal and family weight history. Changes in diurnal profiles of plasma metabolites and hormones were measured to probe mechanisms.

Methods: Adults identified as OP (n = 22; BMI: 23.

Free-Living Responses in Energy Balance to Short-Term Overfeeding in Adults Differing in Propensity for Obesity.

Objective: Free-living adaptive responses to short-term overfeeding (OF) were explored as predictors of longitudinal weight change in adults classified as having obesity resistance (OR) or obesity proneness (OP) based on self-identification and personal/family weight history.

Methods: Adults identified as OP (n = 21; BMI: 23.8 ± 2.

Effects of short-term sex steroid suppression on dietary fat storage patterns in healthy males.

Hypogonadism in males is associated with increased body fat and altered postprandial metabolism, but mechanisms remain poorly understood. Using a cross-over study design, we investigated the effects of short-term sex hormone suppression with or without testosterone add-back on postprandial metabolism and the fate of dietary fat. Eleven healthy males (age: 29 ± 4.

Sedentary behaviour is a key determinant of metabolic inflexibility.

Metabolic flexibility is defined as the ability to adapt substrate oxidation rates in response to changes in fuel availability. The inability to switch between the oxidation of lipid and carbohydrate appears to be an important feature of chronic disorders such as obesity and type 2 diabetes. Laboratory assessment of metabolic flexibility has traditionally involved measurement of the respiratory quotient (RQ) by indirect calorimetry during the fasted to fed transition (e.

Ability to adjust nocturnal fat oxidation in response to overfeeding predicts 5-year weight gain in adults.

Objective: To determine whether metabolic responses to short-term overfeeding predict longitudinal changes in body weight.

Methods: Twenty-four-hour energy expenditure (EE) and substrate utilization were measured at baseline in a room calorimeter following 3 days of eucaloric and hypercaloric feeding (40% excess) in a sample of lean adults (n: 34; age: 28 ± 2 y; BMI: 22 ± 3 kg/m ). Body mass and fat mass (dual-energy x-ray absorptiometry) were measured annually for 5 years.

Endothelial function following glucose ingestion in adults with prediabetes: Role of exercise intensity.

Objective: To determine whether high intensity exercise (HIE) would improve endothelial function more than an isocaloric bout of moderate intensity exercise (MIE) following glucose ingestion in adults with prediabetes.

Methods: Twelve subjects with prediabetes completed all three conditions: time-course matched control and isocaloric exercise (∼200 kcal) at moderate (MIE; at lactate threshold) and high intensity (HIE; 75% of difference between lactate threshold and VO2 peak). Brachial artery flow-mediated dilation (FMD) was measured before exercise (baseline), within 30 min postexercise, and 1 and 2 hr following a 75 g oral glucose tolerance test (OGTT).

Exercise Intensity Modulates Glucose-Stimulated Insulin Secretion when Adjusted for Adipose, Liver and Skeletal Muscle Insulin Resistance.

Little is known about the effects of exercise intensity on compensatory changes in glucose-stimulated insulin secretion (GSIS) when adjusted for adipose, liver and skeletal muscle insulin resistance (IR). Fifteen participants (8F, Age: 49.9±3.

Comparing Simple Insulin Sensitivity Indices to the Oral Minimal Model Postexercise.

Purpose: This study aims to establish whether changes in indices of insulin sensitivity (Si) derived from fasting glucose and an oral glucose tolerance test (OGTT) are comparable to Si determined by the oral minimal model (OMM) in response to acute moderate-intensity exercise (MIE) and high-intensity exercise (HIE).

Methods: Eighteen prediabetic subjects completed three conditions: control (no exercise), ∼ 200 kcal of MIE (∼ 50% of VO2peak), and ∼ 200 kcal of HIE (∼ 80% VO2peak). One hour postexercise (or control), subjects underwent a 75-g OGTT; plasma glucose and insulin were measured to determine Si using several OGTT-based indices (OMM, Belfiore index, Cederholm index, Matsuda index, Gutt index, oral glucose insulin sensitivity index, Stumvoll metabolic clearance rate, Stumvoll insulin sensitivity index, 1/mean OGTT insulin, and 1/insulin incremental area under the curve) and fasting indices (1/homeostatic model assessment for insulin resistance, 1/adipose tissue insulin resistance, 40/fasting insulin, and Quantitative Insulin Sensitivity Check Index).

Effect of an herbal/botanical supplement on recovery from delayed onset muscle soreness: a randomized placebo-controlled trial.

Background: We examined the effects of a proprietary herbal/botanical supplement (StemSport, Stemtech, San Clemente, CA.) suggested to increase circulating stem cells, decrease inflammation, and attenuate exercise induced muscle damage on recovery from delayed onset muscle soreness (DOMS).

Methods: Sixteen subjects (male = 7, female = 9; age 23.

Effect of an herbal/botanical supplement on strength, balance, and muscle function following 12-weeks of resistance training: a placebo controlled study.

Background: StemSport (SS; StemTech International, Inc. San Clemente, CA) contains a proprietary blend of the botanical Aphanizomenon flos-aquae and several herbal antioxidant and anti-inflammatory substances. SS has been purported to accelerate tissue repair and restore muscle function following resistance exercise.