Impact of energy turnover on fat balance in healthy young men during energy balance, energetic restriction and overfeeding

Higher energy flux may improve short-term appetite control in adolescents with obesity: the NEXT study

Recent evidence suggests better appetite control in states of high-energy flux (HEF) in adults and lean children. Nevertheless, it is unknown whether this extends to youth with obesity. This study compares the effects of low, moderate or HEF on short-term appetitive control in adolescents with obesity. Sixteen adolescents with obesity (12-16 years, Tanner stages 3-5, 11 females) randomly completed three conditions: (i) low-energy flux (LEF); (ii) moderate energy flux (MEF; + 250 kcal) and (iii) HEF (HEF; + 500 kcal). Energy flux was achieved in MEF and HEF through elevated energy intake (EI) and concomitant increase in energy expenditure using cycling exercise (65 % VO2peak). Ad libitum EI, macronutrient intake and relative EI were assessed at dinner, subjective appetite sensations taken at regular intervals and food reward measured before dinner. Ad libitum EI at dinner was greater in LEF compared with HEF (P = 0·008), and relative EI (REI) was higher in LEF compared with MEF (P = 0·003) and HEF (P < 0·001). The absolute consumption of carbohydrates was lower in LEF compared with MEF (P = 0·047) and HEF (P < 0·001). Total AUC for hunger and desire to eat was lower in HEF compared with LEF (P < 0·001) and MEF (P = 0·038). Total AUC for prospective food consumption was lower on HEF compared with LEF (P = 0·004). Food choice sweet bias was higher in HEF (P = 0·005) compared with LEF. To conclude, increasing energy flux may improve short-term appetite control in adolescents with obesity.

Association between doubly labelled water-calibrated energy intake and objectively measured physical activity with mortality risk in older adults

BACKGROUND

Physical activity or biomarker-calibrated energy intake (EI) alone is associated with mortality in older adults; the interaction relationship between the combined use of both factors and mortality has not been examined. We evaluated the relationship between mortality and calibrated EI and step counts in older adults.

METHODS

This prospective study included 4,159 adults aged ≥65 years who participated in the Kyoto-Kameoka study in Japan and wore a triaxial accelerometer between 1 April and 15 November 2013. The calibrated EI was calculated based on a previously developed equation using EI biomarkers. The step count was obtained from the accelerometer ≥ 4 days. Participants were classified into the following four groups: low EI (LEI)/low step counts (LSC) group (EI: <2,400 kcal/day in men and <1,900 kcal/day in women; steps: <5,000 /day), n = 1,352; high EI (HEI)/LSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: <5,000 /day), n = 1,586; LEI/high step counts (HSC) group (EI: <2,400 kcal/day in men and < 1,900 kcal/day in women; steps: ≥5,000 /day), n = 471; and HEI/HSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: ≥5,000 /day), n = 750. Mortality-related data were collected until 30 November 2016. We performed a multivariable Cox proportional hazard analysis.

RESULTS

The median follow-up period was 3.38 years (14,046 person-years), and 111 mortalities were recorded. After adjusting for confounders, the HEI/HSC group had the lowest all-cause mortality rate compared to other groups (LEI/LSC: reference; HEI/LSC: hazard ratio [HR]: 0.71, 95% confidence interval [CI]: 0.41-1.23; LEI/HSC: HR: 0.59, 95% CI: 0.29-1.19; and HEI/HSC: HR: 0.10, 95% CI: 0.01-0.76). No significant interaction was observed between the calibrated EI and steps with mortality. The spline model showed that 35-42 kcal/100 steps/day of EI/100 steps was associated with the lowest mortality risk.

CONCLUSIONS

HR mortality risk was lowest at 35-42 kcal/100 steps/day, suggesting that very high (≥56 kcal) or low (<28 kcal) EI/100 steps are not inversely associated with mortality. Adherence to optimal EI and adequate physical activity may provide sufficient energy balance to explain the inverse association with mortality among older Japanese adults.

Validation of energy expenditure and macronutrient oxidation measured by two new whole-room indirect calorimeters

OBJECTIVE

The aim of this study was to validate two new whole-room indirfect calorimeters according to Room Indirect Calorimetry Operating and Reporting Standards (RICORS 1.0).

METHODS

For technical validation, 16 propane combustion tests were performed to determine accuracy and precision of energy expenditure (EE) and ventilation rates of oxygen (VO₂ ), carbon dioxide (VCO₂ ), and respiratory exchange ratio (VCO₂ /VO₂ ). For biological validation, eight participants (mean [SD], age 24.1 [2.5] years; BMI 24.3 [3.1] kg/m² ) underwent four 24-hour protocols under highly standardized conditions: (1) isocaloric sedentary, (2) fasting sedentary, (3) isocaloric active, and (4) fasting active. Reliability (coefficients of variation [CV]) and minimal detectable changes (MDC) were calculated for 24-hour EE, sleeping metabolic rate (SMR), physical activity energy expenditure (PAEE), thermic effect of food (TEF), and macronutrient oxidation rates.

RESULTS

Technical validation showed high reliability and recovery rates for VO₂ (0.75% and 100.8%, respectively), VCO₂ (0.49% and 100.6%), and EE (0.54% and 98.2%). Biological validation revealed CV and MDC for active conditions of 1.4% and 4.3% for 24-hour EE, 1.7% and 5.9% for SMR, and 30.2% and 38.4% for TEF, as well as 5.8% and 10.5% for PAEE, respectively. Mean CV and MDC for macronutrient oxidation rates were 9.9% and 22.9%, respectively.

CONCLUSIONS

The precision of 24-hour EE and SMR was high, whereas it was lower for PAEE and poor for TEF.

Difference in Housing Temperature-Induced Energy Expenditure Elicits Sex-Specific Diet-Induced Metabolic Adaptations in Mice

OBJECTIVE

The aim of this study was to test whether increased energy expenditure (EE), independent of physical activity, reduces acute diet-induced weight gain through tighter coupling of energy intake to energy demand and enhanced metabolic adaptations.

METHODS

Indirect calorimetry and quantitative magnetic resonance imaging were used to assess energy metabolism and body composition during 7-day high-fat/high-sucrose (HFHS) feeding in male and female mice housed at divergent temperatures (20°C vs. 30°C).

RESULTS

As previously observed, 30°C housing resulted in lower total EE and energy intake compared with 20°C mice regardless of sex. Interestingly, housing temperature did not impact HFHS-induced weight gain in females, whereas 30°C male mice gained more weight than 20°C males. Energy intake coupling to EE during HFHS feeding was greater in 20°C versus 30°C housing, with females greater at both temperatures. Fat mass gain was greater in 30°C mice compared with 20°C mice, whereas females gained less fat mass than males. Strikingly, female 20°C mice gained considerably more fat-free mass than 30°C mice. Reduced fat mass gain was associated with greater metabolic flexibility to HFHS, whereas fat-free mass gain was associated with diet-induced adaptive thermogenesis.

CONCLUSIONS

These data reveal that EE and sex interact to impact energy homeostasis and metabolic adaptation to acute HFHS feeding, altering weight gain and body composition change.

Recharacterizing the Metabolic State of Energy Balance in Thrifty and Spendthrift Phenotypes

PURPOSE

The human thrifty phenotype hypothesis presupposes that lower 24-hour (24h) energy expenditure (24EE) during famine preserves body mass and promotes survival. The prevailing view defines thrifty individuals as having a lower 24EE during fasting. However, it is also plausible that the greater decline in 24EE during fasting in thrifty individuals is due to higher 24EE during energy balance conditions (ENBAL). Herein, we provide evidence that this is indeed the case.

METHODS

In 108 healthy subjects, 24EE was measured in a whole-room indirect calorimeter both during ENBAL and 24h fasting conditions. Subjects were categorized as thrifty or spendthrift based on the median value (-162 kcal/day) of the difference in 24EE (adjusted for body composition) between fasting and ENBAL conditions. Concomitant 24h urinary catecholamines were assessed by liquid chromatography-mass spectrometry.

RESULTS

Compared to ENBAL, 24EE decreased during 24h fasting by 172 kcal/day (standard deviation = 93; range, -470 to 122). A greater-than-median decrease in 24EE ("thriftier" phenotype) was due to higher 24EE during ENBAL (+124 kcal/day; P < 0.0001) but not to lower 24EE during fasting (P = 0.35). Greater fasting-induced increase in epinephrine was associated with concomitant lower decrease in 24EE (r = 0.27; P = 0.006).

MAIN CONCLUSION

The greater decrease in 24EE during acute fasting (which characterizes the thrifty phenotype) is not due to reduced metabolic rate during fasting but to a relatively higher 24EE during feeding conditions, and this decrease in 24EE during fasting is accompanied by a smaller increase in epinephrine. These results recharacterize the prevailing view of the short-term 24EE responses that define the human metabolic phenotypes. Clinical Trials: NCT00523627, NCT00687115, NCT02939404.