Aerobic capacity, activity levels and daily energy expenditure in male and female adolescents of the kenyan nandi sub-group

The relative importance of genetic and socio-cultural influences contributing to the success of east Africans in endurance athletics remains unknown in part because the pre-training phenotype of this population remains incompletely assessed. Here cardiopulmonary fitness, physical activity levels, distance travelled to school and daily energy expenditure in 15 habitually active male (13.9±1.6 years) and 15 habitually active female (13.9±1.2) adolescents from a rural Nandi primary school are assessed. Aerobic capacity ([Formula: see text]) was evaluated during two maximal discontinuous incremental exercise tests; physical activity using accelerometry combined with a global positioning system; and energy expenditure using the doubly labelled water method. The [Formula: see text] of the male and female adolescents were 73.9±5.7 ml(.) kg(-1.) min(-1) and 61.5±6.3 ml(.) kg(-1.) min(-1), respectively. Total time spent in sedentary, light, moderate and vigorous physical activities per day was 406±63 min (50% of total monitored time), 244±56 min (30%), 75±18 min (9%) and 82±30 min (10%). Average total daily distance travelled to and from school was 7.5±3.0 km (0.8-13.4 km). Mean daily energy expenditure, activity-induced energy expenditure and physical activity level was 12.2±3.4 MJ(.) day(-1), 5.4±3.0 MJ(.) day(-1) and 2.2±0.6. 70.6% of the variation in [Formula: see text] was explained by sex (partial R(2) = 54.7%) and body mass index (partial R(2) = 15.9%). Energy expenditure and physical activity variables did not predict variation in [Formula: see text] once sex had been accounted for. The highly active and energy-demanding lifestyle of rural Kenyan adolescents may account for their exceptional aerobic fitness and collectively prime them for later training and athletic success

Diets High In Fish And Sugar-sweetened Beverages Affect Energy Expenditure And Energy Balance

BACKGROUND: Recent evidence indicates that dietary patterns, independent of macronutrient and total calorie consumption, alter body weight. This implies an effect of dietary pattern on 24-hour energy expenditure (24hrEE) and energy balance (EnBal). PURPOSE: To evaluate whether a 12-week weight maintaining, macronutrient stable dietary intervention that varies only by meat, fish or sugar sweetened beverages (SSBs) consumption alters 24hrEE and EnBal. METHODS: 32 healthy males were recruited to participate in a 12-week in-patient study and were randomized to a weight-maintaining dietary intervention that contained a varying combination of meat, fish or SSBs in a factorial design. Macronutrient composition across all dietary intervention groups was: 50% carbohydrate; 30% fat; and 20% protein. Twenty-four hour EE and EnBal were measured in a human metabolic chamber (e.g. room calorimeter). All measurements were performed at baseline and week 12. Descriptive statistics and analyses of co-variance were performed to characterize participants at baseline and quantify the changes in 24hrEE and EnBal over time. RESULTS: 28 males (age: 46.6 ± 10.4 years; body mass index 26.9 ± 4.1 kg/m2; predicted energy needs: 2311 ± 241 kilocalories/day [kcals/d]) completed all measurements. Fish consumption resulted in higher 24h EE by 127.4 ± 51.4 kcals/d compared to no fish consumption (p=0.0217). SSB consumption had a 24hEE that was 136.3 ± 52.4 kcals lower (p=0.0166). Approximately 85% of the decrease in 24hEE with SSB consumption was due to lower awake, inactive EE (p=0.0003) and had greater 24hr EnBal when compared to groups without SSBs (p=0.0489). CONCLUSION: Our data indicate that protein and carbohydrate quality (as reflected by fish versus SSB consumption), rather than % daily intake, influence 24hr EE and inactive EE, and thus EnBal. If so, this would imply a metabolic effect of SSB consumption independent of total calories or macronutrient composition that might contribute to overall increasing adiposity rates

Hydration biomarkers and copeptin: relationship with ad libitum energy intake, energy expenditure, and metabolic fuel selection

Background/Objective Evidence from non-human species indicate that hydration and arginine vasopressin (AVP) influence fuel selection, energy expenditure (EE), and food intake, but these relationships are unclear in humans. We sought to assess whether hydration biomarkers [24-h urine volume (UVol) and urine urea nitrogen concentration (UUN)] and copeptin (a surrogate for AVP) are associated with 24-h EE, respiratory quotient (RQ), and daily energy intake (DEI). Subjects/Methods In a secondary analysis of collected data, we selected healthy adults (Group 1, n = 177) who had 24-h whole-room indirect calorimetry measurements in energy balance with 24-h urine collection and fasting copeptin measurements (n = 117), followed by 3 days ad libitum food intake. A separate group (Group 2, n = 284) with hydration markers and calorimetry measurements was also studied. The main outcome measures were 24-h RQ, 24-h EE, DEI, substrate oxidation. Results In Group 1, lower 24-h UVol and higher 24-h UUN, indicating lower hydration, were correlated with lower 24-h RQ (r = 0.35, p < 0.0001, and r = −0.29, p = 0.0001, respectively; results similar in Group 2) and predicted subsequent reduced DEI (r = 0.20, p = 0.01, and r = −0.27, p = 0.0003, respectively), adjusted for confounders. Copeptin was independently associated with 24-h lipid oxidation (r = −0.23, p = 0.01). In Group 2, lower hydration was associated with reduced 24-h EE (24-h UVol: r = 0.29, p < 0.0001; 24-h UUN: r = −0.25, p < 0.0001). Conclusions Hydration biomarkers were associated with metabolic differences characterized by altered food intake, fuel selection, and possibly EE. Independently, copeptin was associated with higher lipid oxidation

Higher Urinary Dopamine Concentration is Associated with Greater Ad Libitum Energy Intake in Humans

OBJECTIVE: This study aimed to assess the relationship between dopamine, a neurotransmitter involved in feeding behavior, and ad libitum energy intake in humans. METHODS: Healthy individuals (n = 158; 72 Native American, 50 white, 18 black, and 18 Hispanic participants; BMI: 33 [SD 9] kg/m2 ; body fat: 33% [SD 9%]) were admitted for two inpatient studies investigating the determinants of ad libitum energy intake and assessed for 3 days using a highly reproducible, computerized vending machine paradigm. Urine was collected for 24 hours during eucaloric conditions prior to the ad libitum feeding period, and urinary dopamine excretion rate was quantified by high-performance liquid chromatography. RESULTS: Urinary dopamine excretion rate was on average 346 ± 106 μg over 24 hours and was positively correlated with BMI (r = 0.28, P < 0.0001). Higher dopamine concentrations were associated with lower cognitive restraint (ρ = -0.25, P = 0.005) and greater total ad libitum energy intake (r = 0.29, P = 0.0002). However, after adjustment for anthropometrics, in black and white cohorts, higher dopamine concentrations were associated with greater total ad libitum energy intake (r = 0.70, P = 0.001 and r = 0.33, P = 0.02, respectively), whereas no associations were observed in Native American or Hispanic cohorts (all P > 0.3). CONCLUSIONS: Higher urinary dopamine concentrations are associated with greater ad libitum energy intake, indicating a role for dopamine in the reward pathway regulating human feeding behavior

Reduced metabolic efficiency in sedentary eucaloric conditions predicts greater weight regain in adults with obesity following sustained weight loss

Background: Successful long-term weight loss maintenance after caloric restriction (CR) is rarely achieved. Besides known metabolic, behavioural, and cognitive factors, 24-hour energy expenditure (24hEE) relative to body size (i.e., metabolic efficiency) might influence subsequent weight loss maintenance. Methods: Eleven participants with obesity (BMI = 39.0 ± 8.7 kg/m2, body fat = 36.1 ± 6.4%) had 24hEE measured in a whole-room indirect calorimeter during eucaloric conditions and weight stability prior to starting a 6-week inpatient CR study (50% of daily energy needs). Twenty-four-hour energy expenditure was adjusted via regression analysis for fat free mass (FFM) and fat mass (FM) by DXA. Body composition was reassessed at the end of CR and after 1-year follow-up. Free-living weight was assessed by monthly weight measurements during 12 months. Results: After 6-week CR, participants lost 8.5 ± 2.7% weight (FFM: -6.3 ± 3.6 kg, FM: -3.4 ± 1.2 kg) but regained 5.1 ± 8.0% 1 year following CR, which was mostly due to FFM regain (+5.7 ± 5.5 kg) and unchanged FM. A relatively higher 24hEE by 100 kcal/day prior to CR was associated with an average greater rate of weight regain by +0.3 kg/month during follow-up and a greater final weight regain by +5.1 kg after 1 year of follow-up. Conclusion: These results suggest that reduced metabolic efficiency in 24hEE during eucaloric, sedentary conditions may predict greater weight regain after CR-induced weight loss

Secular trends and determinants of ad libitum energy intake measured in a research setting from 1999-2020

Introduction: Historically, secular and seasonal trend analyses have been examined using self-report measures of intake. Rarely are objective measures and known determinants of dietary intake used in these analyses. Our objective was to quantify the seasonal and secular differences in an objective ad libitum intake paradigm while considering the contribution of determinants, such as fat-free mass (FFM) index and spontaneous physical activity (SPA) limited to the restricted space of a whole-room calorimeter. Methods: For this study, recruitment of N = 292 healthy, diabetes free, adults occurred from 1999 to 2020. Assessment during their 10-day stay included body composition (by DXA), SPA (by an approximately 24-h stay in whole-room calorimetry), and ad libitum intake (by a vending machine for 3 days). This secondary analysis used general linear models (GLM) to investigate secular and seasonal differences while adjusting for sex, age, FFM index, FM (fat mass) index, SPA, and race/ethnicity. Results: FFM index and SPA were positively associated with all intake measures (p < 0.05). In all adjusted seasonal models, season did not affect intake. Adjusted secular trends models (kcals/year) demonstrated a decrease in total kcals (β = −55), intake as percent weight maintaining energy needs (β = −2), protein kcals (β = −10), fat kcals (β = −27), and carbohydrates kcals (β = −22) (all p < 0.05). After further adjustment for SPA, significance remained in all intake measures (p < 0.05). Secular trends in body composition revealed no changes in weight, BMI, and percent body fat (all p > 0.20). Discussion: Our results indicate that over time, ad libitum intake decreased in this controlled research setting and remained significant even after accounting for positive determinants of intake. A significant ad libitum decrease, coupled with no change in body composition, may highlight a participant bias toward calorie restriction in a controlled setting over time and deserves further investigation