scholarly journals Thermic effect of a meal

1992 ◽  
Vol 67 (2) ◽  
pp. 187-194 ◽  
Author(s):  
L. S. Piers ◽  
M. J. Soares ◽  
R. N. Kulkarni ◽  
P. S. Shetty

Five apparently healthy, chronically undernourished (UN) male volunteers aged between 18 and 30 years were studied before and after 12 weeks of dietary supplementation. The thermic effect of a meal (TEM) was measured over a period of 6 h using a ventilated-hood system. Results indicated a significant increase in body-weight after supplementation due to increases in body fat and fat-free mass (FFM) in the proportion of 69% and 31% respectively. The basal metabolic rates (BMR) measured post supplementation were significantly higher in absolute terms, with a trend towards higher values when adjusted for the changes in FFM. TEM responses measured after 12 weeks of supplementation were significantly lower when expressed either in absolute terms (presupplementation 227.0 kJ v. post supplementation 193.5 kJ), or as a percentage of the energy density of the meal (9.1% v. 7.7%). This lower TEM was reciprocal to the changes in the BMR (r −0.86). The post-meal total energy output (PMTEO) was, however, not significantly different after 12 weeks of dietary supplementation. The unchanged PMTEO would indicate an unaltered ‘thermogenic capacity’, following supplementation, in these chronically undernourished subjects. These results confirm our earlier conclusion that, in chronic undernutrition, the thermic response to a meal may not contribute to any energy saving.Chronic undernutrition: Dietary supplementation: Basal metabolic rates: Thermic effect: Substrate oxidation rates

1992 ◽  
Vol 67 (2) ◽  
pp. 177-185 ◽  
Author(s):  
L. S. Piers ◽  
M. J. Soares ◽  
P. S. Shetty

The thermic effect of a standard liquid meal (TEM; energy 2.5 MJ; containing (g/kg) protein 100, fat 150, carbohydrate 750; volume 350 ml) was measured in a chronically undernourished (UN; n 9) group of human subjects and was compared with results from two control groups, one normal weight (NW)-for-height (BMI > 20; n 10) and the other underweight (UW)-for-height (BMI < 18, n 10), using a ventilated-hood system over a period of 6 h after ingestion of the meal. Results indicated that the UN subjects had lower values for body-weight, height, percentage fat and fat-free mass (FFM) compared with those of either control group. Basal metabolic rates were lowest in the UN group in absolute terms; however, there were no significant differences among groups on an analysis of covariance (ANACOVA) with FFM as the covariate. TEM responses in the UN group were significantly higher when expressed either in absolute terms or as a percentage of the energy density of the meal. The post-meal total energy output was significantly lower (P < 0.05) in the UW and UN groups as compared with the NW group in absolute terms; however, on adjusting for differences in FFM (by ANACOVA) there were no significant differences among groups. This would suggest that in the chronically undernourished thermogenic responses to a meal are unlikely to contribute towards any energy saving and may not constitute a part of any adaptive response to the undernourished state.Chronic undernutrition: Thermic effect: Substrate oxidation rates: Body composition


2000 ◽  
Vol 98 (5) ◽  
pp. 587-592 ◽  
Author(s):  
Patrick SCHRAUWEN ◽  
Ellen E. BLAAK ◽  
Dorien P. C. van AGGEL-LEIJSSEN ◽  
Lars B. BORGHOUTS ◽  
Anton J. M. WAGENMAKERS

When using 13C or 14C tracers to study substrate metabolism, an acetate correction factor should be applied to correct for loss of label in the exchange pathways of the tricarboxylic acid cycle. We have shown recently that the [13C]acetate recovery factor has a high inter-individual variability and should therefore be determined in every subject. In the present study we examined the factors that might explain some of the variability between subjects in acetate recovery factor. Data were pooled from four different studies with identical protocols, in which the acetate recovery factor was measured, prior to an intervention, to correct plasma fatty acid oxidation rates. Acetate recovery was measured after 2 h of [1,2-13C]acetate infusion at rest followed by 1 h of cycling exercise at 40–50% of maximal oxygen uptake. Inter-individual variance in acetate recovery was 12.0% at rest and 16.1% during exercise. Stepwise regression revealed that, at rest, 37.1% of the acetate recovery could be accounted for by basal metabolic rate adjusted for fat-free mass, percentage body fat and respiratory quotient (RQ). During exercise, 69.1% of the variance in acetate recovery could be accounted for by energy expenditure adjusted for fat-free mass, % body fat and RQ. In conclusion, we show that the acetate recovery factor has a high inter-individual variability, both at rest and during exercise, which can partly be accounted for by metabolic rate, RQ and % body fat. These data indicate that the acetate recovery factor needs to be determined in every subject, under similar conditions as used for the tracer-derived determination of substrate oxidation. Failure to do this might result in large under- or over-estimation of plasma substrate oxidation, and hence to artificial differences between groups.


Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Peter T Katzmarzyk ◽  
Eric Ravussin

Introduction: African Americans (AA) experience higher rates of obesity and related disorders than the general U.S. population. It has been hypothesized that the increased risk of obesity among AA may be explained, in part, by lower levels of energy expenditure (EE) and lower levels of fat oxidation. However, many different measures of EE and substrate oxidation have been employed across previous studies. Objective: The objective of this study was to compare multiple measures of EE and substrate oxidation among White (W) and AA adults. We hypothesize that AA will have lower EE and lower fat oxidation rates than W. Methods: A sample of 12 young (ages 22 to 35 y), non-obese AA adults was recruited from the local community and pair-matched by age, sex and body mass index (BMI) to a sample of 12 W adults. Height and weight were measured and BMI was calculated (kg/m 2 ). Total fat mass (FM) and fat free mass (FFM) were measured using dual energy x-ray absorptiometry. Resting EE (REE) and respiratory quotient (RQ) were measured in a fasting state using a metabolic cart; 24-hour EE, 24-h RQ, sleep EE and sleep RQ were measured in a whole room calorimeter; and free-living total daily EE (TDEE) was measured over two weeks using doubly labelled water. Physical activity level (PAL) was computed as TDEE/REE. Differences between W and AA were determined using general linear models, adjusting for FFM. Results: The analytic sample had a mean age of 27.0 y (SD 4.3 y) and mean BMI of 22.9 kg/m 2 (SD 2.9 kg/m 2 ). There were no significant differences in age, BMI, FM or FFM between W and AA (all p>0.05). However, W had significantly higher REE (1459 vs 1305 kcal/day; p=0.001), 24-h EE (1826 versus 1737 kcal/day; p=0.02), sleep EE (1509 vs 1405 kcal/day; p=0.005); but not TDEE (2452 vs 2313 kcal/day; p=0.30) compared to AA. There were no race differences in RQ (0.83 vs 0.83; p=0.93), 24-h RQ (0.86 vs 0.88; p=0.24) or sleep RQ (0.86 vs 0.87; p=0.44). On the other hand, AA had higher PAL (1.34 vs 1.26; p=0.04) compared to W. Conclusions: Non-obese W adults demonstrated higher REE, 24-h EE, and sleep EE compared to AA, but had similar levels of free-living TDEE. It appears as though some AA adults may compensate for lower REE by increased physical activity, which may be an effective strategy to prevent weight gain and obesity.


1992 ◽  
Vol 68 (3) ◽  
pp. 593-602 ◽  
Author(s):  
M. J. Soares ◽  
R. N. Kulkarni ◽  
L. S. Piers ◽  
M. Vaz ◽  
P. S. Shetty

The objective of the present study was to examine the influence of energy supplementation and its cessation thereafter on the basal metabolic rates (BMR) of chronically undernourished individuals. Seven apparently healthy males were supplemented daily with 3.35 MJ (15 g protein, 35 g fat, 105 g carbohydrate) for 12 weeks. The average gain in body-weight was 1.9 kg (body fat, 58%; fat-free mass (FFM), 42%). The rise in BMR exceeded that accounted for by the increases in FFM during the 12 weeks of supplementation and was attributed to increases in the amount and activity of the visceral tissue as well as to an added cost of lipogenesis. At 12 weeks after cessation of the supplement, body-weights and FFM had decreased to presupplementation levels. BMR at this stage were significantly lower than at the 12th week of supplementation, when expressed per kg FFM or when adjusted for FFM using an analysis of covariance. These results suggest an increase in the metabolic efficiency during this negative energy balance period. The study demonstrates that, in the chronically undernourished, the changes in BMR are reversible and, hence, physiologically important to the process of adaptation to low-energy intakes.


2011 ◽  
Vol 23 (3) ◽  
pp. 411-431 ◽  
Author(s):  
Robert G. McMurray ◽  
Peter A. Hosick

The study evaluated the interactions of puberty and obesity on substrate oxidation of overweight girls (n = 38) and boys (N = 35; BMI > 85th percentile) matched for gender, age, and puberty (pre/pubertal) with normal weight girls and boys. Metabolic rates (VO2) were obtained during rest and at 4, 5.6 and 8 k/h. Carbohydrate oxidation rates (mg/kgFFM/min) adjusted for % predicted VO2max, were higher for prepubertal OW children than pubertal children (p < .03). Fat oxidation rates were higher for NW prepubertal boys compared with other boys. Results indicate that OW children, regardless of gender or pubertal status, increase their carbohydrate oxidation rate to compensate for higher than normal metabolic rates. The effects of obesity on the substrate use is marginally related to puberty.


2013 ◽  
Vol 38 (3) ◽  
pp. 314-319 ◽  
Author(s):  
Nicole M. Mitchell ◽  
Jeffery A. Potteiger ◽  
Brittney Bernardoni ◽  
Randal P. Claytor

We examined the effects of consuming a 6% carbohydrate (CHO) beverage during exercise on substrate oxidation in active, young Caucasian women with higher body fat (HF) (>25%) and lower body fat (LF) (<25%). The HF group (n = 9) had 32.4% ± 5.6% fat and the LF group (n = 8) had 20.0% ± 3.0% fat. Subjects completed 2 sessions of 45 min of treadmill exercise at 55% of maximal oxygen consumption. Immediately prior to and at 15-min intervals during exercise, subjects consumed 25% of a total volume of a CHO beverage (1 g CHO·kg−1) or a placebo (PLC). During exercise and for 2 h after exercise, expired gases were analyzed to determine oxidation rates for CHO (CHO-OX) and fat (FAT-OX). During exercise, significant differences (p < 0.05) in CHO-OX (mg·kg fat-free mass−1·min−1) were found between groups for the CHO trial (LF, 35.4 ± 4.7 vs. HF, 29.8 ± 3.6) and the PLC trial (LF, 33.7 ± 6.4 vs. HF, 26.3 ± 4.3). CHO-OX was significantly higher during the first hour of recovery in both the LF group (CHO, 9.3 ± 2.1 vs. PLC, 5.3 ± 2.4) and the HF group (CHO, 8.7 ± 2.0 vs. PLC, 4.2 ± 1.0), but during the second hour of recovery, only the HF group had a higher CHO-OX (CHO, 5.3 ± 1.8 vs. PLC, 3.9 ± 1.1). FAT-OX was significantly lower during the first hour of recovery in both the LF group (CHO, 0.6 ± 0.4 vs. PLC, 1.0 ± 0.4) and the HF group (CHO, 0.4 ± 0.4 vs. PLC, 1.4 ± 0.4), as well as during the second hour of recovery in both the LF group (CHO, 0.8 ± 0.4 vs. PLC, 1.3 ± 0.5) and the HF group (CHO, 0.9 ± 0.6 vs. PLC, 1.6 ± 0). CHO ingestion promotes CHO-OX and suppresses FAT-OX during and following exercise in physically active women with low and high levels of body fat.


1992 ◽  
Vol 67 (2) ◽  
pp. 165-175 ◽  
Author(s):  
L. S. Piers ◽  
M. J. Soares ◽  
Tania Makan ◽  
P. S. Shetty

The variation in the thermic effect of a meal (TEM) was investigated in two groups of five subjects following a standard test meal. Results demonstrated a 50 % lower response over 6 h, in the same subjects, when measured intermittently (protocol 2) as compared with a continuous measurement (protocol 1). The variation in TEM among occasions (measured on three occasions in each subject) was large (coefficient of variation (CV) 18.7%, P < 0.02). However, the post-meal total energy output (CV 1.4%, P > 0.05), non-protein respiratory quotient (CV 1.9%, P > 0.05) and substrate oxidation rate were not different (P > 0.05) in the same individual on separate occasions. Small variations in the basal metabolic rate (BMR) from occasion to occasion (CV 2.6%) contributed to the variation in TEM. However, after allowing for the changes in BMR, variation in TEM (CV 8.6%, P > 0.05) was still sizeable though not statistically significant.Thermic effect: Methodology: Variation of thermic effect


2000 ◽  
Vol 89 (3) ◽  
pp. 977-984 ◽  
Author(s):  
Gary R. Hunter ◽  
Carla J. Wetzstein ◽  
David A. Fields ◽  
Amanda Brown ◽  
Marcas M. Bamman

The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61- to 77-yr-old men ( n = 8) and women ( n = 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE − REE + thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance ( P = 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.


1991 ◽  
Vol 260 (3) ◽  
pp. E430-E435 ◽  
Author(s):  
I. Raz ◽  
A. Katz ◽  
M. K. Spencer

The effect of epinephrine (E) infusion on insulin-mediated glucose metabolism in humans has been studied. Eight glucose-tolerant men were studied on two separate occasions: 1) during 120 min of euglycemic hyperinsulinemia (UH, approximately 5 mM; 40 mU.m-2.min-1); and 2) during UH while E was infused (UHE, 0.05 microgram.kg-1.min-1). Biopsies were taken from the quadriceps femoris muscle before and after each clamp. Glucose disposal, correcting for endogenous glucose production, was 36 +/- 3 and 18 +/- 2 (SE) mumol.kg fat-free mass (FFM)-1.min-1 during the last 40 min of UH and UHE, respectively (P less than 0.001). Nonoxidative glucose disposal (presumably glycogenesis) averaged 23.0 +/- 3.0 and 4.0 +/- 1.1 (P less than 0.001), whereas carbohydrate oxidation (which is proportional to glycolysis) averaged 13.1 +/- 1.4 and 15.3 +/- 1.1 mumol.kg FFM-1.min-1 (P less than 0.05) during UH and UHE, respectively. UHE resulted in significantly higher contents of UDP-glucose, hexose monophosphates, postphosphofructokinase intermediates, and glucose 1,6-bisphosphate (G-1,6-P2) in muscle (P less than 0.05-0.001), but there were no significant differences in high-energy phosphates or fructose 2,6-bisphosphate (F-2,6-P2) between treatments. Fractional activities of phosphorylase increased (P less than 0.01), and glycogen synthase decreased (P less than 0.001) during UHE. It is concluded that E inhibits insulin-mediated glycogenesis because of an inactivation of glycogen synthase and an activation of glycogenolysis. E also appears to inhibit insulin-mediated glucose utilization, at least partly, because of an increase in G-6-phosphate (which inhibits hexokinase) and enhances glycolysis by G-1,6-P2-, fructose 6-phosphate-, and F-1,6-P2-mediated activation of PFK.


2020 ◽  
Vol 16 (5) ◽  
pp. 371-376
Author(s):  
B. Taati ◽  
H. Rohani

The present study aimed to investigate the potential effect of different aerobic fitness levels on substrate oxidation in trained taekwondo athletes. 57 male athletes (age 21.10±7.79 years; VO2max 50.67±6.67 ml/kg/min) with regular weekly taekwondo training and training experience of at least three years completed a graded exercise test to exhaustion on a treadmill. Maximal fat oxidation (MFO), the exercise intensity related to MFO (Fatmax), and carbohydrate (CHO) oxidation rate were measured using indirect calorimetry methods. The athletes then were divided into a low (<50 ml/kg/min, n=18) and high (>50 ml/kg/min, n=39) VO2max group. The average MFO was higher in the high VO2max group than in the low VO2max group (0.46±0.19 vs 0.28±0.11 g/min; P<0.001). Although Fatmax tended toward higher values in the high VO2max group, no difference was observed between the groups (49.15±15.22 vs 42.42±12.37% of VO2max; P=0.18). It was also shown that the high VO2max group had a lower CHO oxidation rate and a higher fat oxidation rate at given exercise intensities. In conclusion, it seems that MFO and substrate oxidation rates in taekwondo athletes can be influenced by aerobic fitness level such that the athletes with higher VO2max appeared to use more fat as a fuel source for energy supply during a given exercise.


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