Biomedical subjects

A Tremblay

Publications and source records attributed to A Tremblay.

At least 109 records · Page 6Linked to original sources

PubMed1999

Physical activity and obesity.

The regular practice of physical activity promotes metabolic adaptations that facilitate the regulation of energy and fat balance. These effects are important for a better control of body weight in the obese individual and should enable him or her to involve adipose tissue to a lesser extent in this regulation. Physical activity favours a negative energy and fat balance, particularly if activities are prolonged and vigorous. The achievement of a negative energy and fat balance with physical activity also strongly depends on the nutritional context in which it is performed. In the long term, an active lifestyle and low-fat food habits are expected to induce a substantial body weight loss in the obese. This weight loss is progressively attenuated over time, presumably because of the decreased impact of a reduced adipose tissue mass on the regulation of energy and fat balance. For the obese individual complying with an activity programme and healthy food habits, a body weight loss of 10% is a realistic goal before the occurrence of resistance to further loss of body fat.

Diet, Fat-Restricted↗

PubMed1999

Influence of intense physical activity on energy balance and body fatness.

The reduced contribution of physical activity to daily energy expenditure and the accessibility to high-fat foods have put an excessive burden on energy balance, resulting in an increase in the prevalence of obesity throughout the world. In this context, fat gain can be seen as a natural adaptation to deal with a fattening lifestyle, since the hormonal adaptations that accompany fat gain favour the readjustment of energy expenditure to energy intake. Intense physical activity would also seem to facilitate the regulation of energy balance, since it increases the energy cost of exercise, increases post-exercise energy expenditure and the potential of skeletal muscles to utilize lipids, and also favours a decrease in post-exercise intake. Moreover, the effects of intense exercise seem to be mediated by an activation of sympathetic nervous system activity that seems to be specific to skeletal muscle. It is also important to manipulate macronutrient composition in order to reduce fat intake, because unhealthy food habits can favour overfeeding and thus overcome the energy deficit caused by regular physical activity. Under free-living conditions, the combination of vigorous activity and healthy food practices can amount to a substantial weight loss which is comparable with that of other non-surgical approaches to treat obesity.

Adipose Tissue↗

PubMed1999

Postexercise macronutrient oxidation: a factor dependent on postexercise macronutrient intake.

BACKGROUND: It has been widely shown that exercise increases postexercise fat oxidation and energy expenditure. OBJECTIVE: The aim of this study was to investigate the effect of exercise on postexercise substrate oxidation and energy expenditure when the exercise-induced expenditure of energy and macronutrients oxidized is compensated by an equivalent intake immediately after exercise. DESIGN: Twenty-four-hour energy expenditure (24EE) and macronutrient oxidation of 8 young men were measured in a whole-body indirect calorimeter under the 2 following, randomly assigned conditions: 1) a control session of sedentary activities in the calorimeter for 61 h and 2) a similar session preceded by 60 min of exercise at 50% of maximal oxygen consumption. Immediately after exercising, subjects ingested a milk shake containing the same amount of energy (above resting metabolic rate) expended during exercise and with a food quotient corresponding to the mean exercise respiratory quotient. 24EE and substrate oxidation were compared between conditions on a day-to-day basis (days 1, 2, and 3) and for the 61-h observation period. RESULTS: There was no difference in 24EE between the 2 conditions. Moreover, the composition of the postexercise fuel mix oxidized, as reflected by the respiratory quotient, was strictly the same under the 2 conditions. CONCLUSION: Voluntary postexercise compensations in energy and macronutrient intakes play a major role in the ability of exercise to alter postexercise substrate utilization.

Adult↗

PubMed1999

Apolipoprotein E polymorphism and the relationships of physical fitness to plasma lipoprotein-lipid levels in men and women.

PURPOSE: A high level of cardiovascular fitness is generally associated with a plasma lipoprotein-lipid profile predictive of a low cardiovascular disease risk. We have investigated whether apolipoprotein (apo) E polymorphism could alter the relationships of physical fitness to plasma lipoprotein-lipid levels in a sample of healthy untrained subjects (64 premenopausal women and 65 men). METHODS: Subjects were grouped according to gender and apo E phenotype determined by isoelectric focusing electrophoresis. RESULTS: In both genders, VO2max expressed in mL x kg(-1) x min(-1) was negatively correlated with plasma triglyceride levels in apo E2 carriers and apo E3 homozygotes (-0.55< or =r< or =0.31; P<0.05), whereas these associations were not found in apo E4 groups. Plasma low-density lipoprotein (LDL)-C levels were negatively associated with VO2max (r = -0.39; P<0.05) only in women homozygotes for apo E3 whereas VO2max was positively correlated with plasma high-density lipoprotein (HDL)2-C levels only in men (r = 0.51; P<0.001) and women (r = 0.65; P<0.001) who were apo E3 homozygotes. A control for concomitant association with body fat mass and glucose intolerance performed by partial correlation analyses revealed that, with the exception of the plasma HDL2-C levels in the apo E3 homozygotes, most of the significant associations between VO2max (mL x kg(-1) x min(-1)) and plasma lipoprotein-lipid levels were mediated by concomitant variation in body fatness and glucose tolerance. CONCLUSIONS: These results suggest that the magnitude of the relationships between VO2max and plasma lipoprotein-lipid levels is influenced by the apo E polymorphism. Thus, apo E2 carriers may be particularly responsive to improved fitness, thereby preventing the development of hypertriglyceridemia and type III dyslipoproteinemia.

Adult↗

PubMed1999

Physical activity and preference for selected macronutrients.

OBJECTIVE: The impact of physical exercise on macronutrient preferences was examined with a perspective to improve preventive and therapeutic strategies of obesity. DESIGN: The literature was reviewed pertaining to the acute effects of physical activity and the short-term and chronic effects of exercise training on macronutrient preferences. RESULTS: The presently available literature does not permit to establish a consensus regarding the impact of physical activity, be it acute or long-term, on macronutrient selection. However, one observation stands out and that is the fact that dietary fat intake needs to be controlled in order for exercise to produce a negative energy and fat balance. CONCLUSION: Because active individuals do not systematically choose foods that are low in fat content, it is important to provide nutritional guidelines in a context where physical activity aims at reducing or better controlling body weight.

Diet↗

PubMed1999

Dominant activity of activation function 1 (AF-1) and differential stoichiometric requirements for AF-1 and -2 in the estrogen receptor alpha-beta heterodimeric complex.

Estrogenic responses are now known to be mediated by two forms of estrogen receptors (ER), ERalpha and ERbeta, that can function as homodimers or heterodimers. As homodimers the two have been recently shown to exhibit distinct transcriptional responses to estradiol (E2), antiestrogens, and coactivators, suggesting that the ER complexes are not functionally equivalent. However, because the three possible configurations of ER complexes all recognize the same estrogen response element, it has not been possible to evaluate the transcriptional properties of the ER heterodimer complex by transfection assays. Using ER subunits with modified DNA recognition specificity, we were able to measure the transcriptional properties of ERalpha-ERbeta heterodimers in transfected cells without interference from the two ER homodimer complexes. We first demonstrated that the individual activation function 1 (AF-1) domains act in a dominant manner within the ERalpha-ERbeta heterodimer: the mixed agonist-antagonist 4-hydroxytamoxifen acts as an agonist in a promoter- and cell context-dependent manner via the ERalpha AF-1, while activation of the complex by the mitogen-activated protein kinase (MAPK) pathway requires only the ERalpha- or ERbeta-responsive MAPK site. Using ligand-binding and AF-2-defective mutants, we further demonstrated that while the ERalpha-ERbeta heterodimer can be activated when only one E2-binding competent partner is present per dimer, two functional AF-2 domains are required for transcriptional activity. Taken together, the results of this study of a retinoid X receptor-independent heterodimer complex, the first such study, provide evidence of different stoichiometric requirements for AF-1 and -2 activity and demonstrate that AF-1 receptor-specific properties are maintained within the ERalpha-ERbeta heterodimer.

Amino Acid Sequence↗

PubMed1999

Gender difference in postprandial lipemia : importance of visceral adipose tissue accumulation.

Insulin resistance, hyperinsulinemia, hypertriglyceridemia, and low HDL-cholesterol concentrations are common features of a plurimetabolic syndrome, which increases the risk of coronary artery disease. Although it has been proposed that the development of atherosclerosis through alterations in plasma lipid levels could be a postprandial phenomenon, most studies on gender differences in plasma lipoprotein-lipid concentrations have reported fasting levels. Therefore, the aim of our study was to examine the response of postprandial triglyceride-rich lipoproteins to a standardized meal in 63 men and 25 women. In addition to the measurement of fasting and postprandial plasma lipid levels, numerous physical and metabolic variables were assessed, including body composition by underwater weighing and body fat distribution by computed tomography. Although no gender difference was noted in total body fat mass, men were characterized by a preferential accumulation of abdominal adipose tissue as revealed by an increased waist circumference and a greater visceral adipose tissue accumulation (50% difference) compared with women (P<0.001). Men also showed a greater plasma triglyceride response (P<0.005) as well as increased postprandial insulin and free fatty acid levels compared with women (P<0.01). Visceral adipose tissue was significantly associated with the postprandial triglyceride response in both genders (men: r=0.49, P<0. 0001; women: r=0.43, P<0.05). Finally, when men and women were matched for visceral adipose tissue accumulation, the gender difference in postprandial plasma triglyceride response was eliminated. Thus results of the present study suggest that the well known gender difference in visceral adipose tissue accumulation is an important contributing factor involved in the exaggerated postprandial triglyceride-rich lipoprotein response noted in men compared with women.

Adipose Tissue↗

PubMed1999

Is visceral adiposity a significant correlate of subcutaneous adipose cell lipolysis in men?

The aim of the present study was to examine whether site differences in s.c. adipose tissue (AT) lipolysis may be considered a contributing factor to the altered metabolic risk profile of visceral compared to peripheral obese men once the concomitant variation in adipose cell size is taken into account. For this purpose, sc abdominal and femoral fat cell lipolytic responses were investigated in two groups of men (body mass index, 28 +/- 2 kg/m2), aged 36 +/- 3 yr, who were matched for both s.c. abdominal AT area (256 +/- 64 cm2) and s.c. abdominal adipose cell weight (0.55 +/- 0.08 microg lipid/cell) but were characterized by either a high (162 +/- 29 cm2; n = 18) or a low (101 +/- 21 cm2; n = 18) visceral AT deposition. The maximal lipolytic response to epinephrine or to isoproterenol (beta-adrenergic agonist) as well as the maximal antilipolytic effect of either epinephrine or clonidine (alpha2-adrenergic agonist) assessed in s.c. adipocytes were similar among men with low vs. high levels of visceral AT. However, the beta-adrenoceptor sensitivity was increased in s.c. abdominal adipose cells of individuals with a high visceral AT accumulation compared to those with a low intraabdominal fat deposition. Positive relationships were also found between the lipolytic sensitivity of s.c. abdominal adipocytes and plasma insulin concentrations measured in the fasting state and after an oral glucose load. These results suggest that variation in the degree of visceral adiposity in men does not seem to be associated with differences in regional adipose cell maximal lipolytic capacity once fat cell size is taken into account. However, the greater beta-adrenoceptor lipolytic sensitivity of s.c. abdominal adipocytes could be considered a significant correlate of the increased insulinemia observed among men characterized by high levels of visceral AT.

Abdomen↗

PubMed1999

Linkage and association of the sodium potassium-adenosine triphosphatase alpha2 and beta1 genes with respiratory quotient and resting metabolic rate in the Québec Family Study.

The purpose of this study was to examine the relationship between the alpha2 (exon 1 and exon 21-22 with BglII) and beta1 (MspI and PvuII) genes of the sodium potassium adenosine triphosphatase and resting metabolic rate (RMR) and respiratory quotient (RQ). The sample included 582 participants from 171 families of the Québec Family Study. RMR and RQ were adjusted for age, sex, fat mass, and fat free mass. Sib-pair analyses indicated a significant linkage between RQ and the alpha2 exon 1 marker (P = 0.03) and the alpha2 exon 21-22 marker (P = 0.02). No linkage was detected between the beta1 markers and either RMR or RQ, whereas RMR was not linked with the alpha2 makers. There was a significant interaction (P < 0.0003) between alpha2 exon 1 carrier status and age group [younger (< 45 yr) vs. older (> or = 45 yr) adults] for RQ. The association between carrier status and RQ was significant in younger adults (RQ = 0.76 in carriers vs. 0.80 in noncarriers, P < 0.0001) but was not in older adults (RQ = 0.81 in carriers vs. 0.80 in noncarriers). The alpha2 exon 1 gene accounted for approximately 9.1% and 0.3% of the variance in RQ in younger and older adults, respectively. The results suggest that the sodium potassium adenosine triphosphatase alpha2 gene may play a role in fuel oxidation, particularly in younger individuals.

Adolescent↗

PubMed1999

Age-related increase in visceral adipose tissue and body fat and the metabolic risk profile of premenopausal women.

OBJECTIVE: Age-related differences in body fat and, more specifically, in the accumulation of abdominal visceral adipose tissue (AT) were examined as potential covariates of the age-related difference in the metabolic profile predictive of cardiovascular disease (CVD) risk observed in young, as compared with middle-aged, premenopausal women. RESEARCH DESIGN AND METHODS: Body composition, AT distribution, plasma lipoprotein-lipid levels, glucose tolerance, and plasma insulin concentrations were assessed in a sample of 122 young women (27.4+/-7.5 years, mean +/- SD) and compared with a sample of 52 middle-aged premenopausal women (49.5+/-5.3 years) who still had a normal menstrual cycle. RESULTS: Middle-aged women were characterized by elevated levels of total abdominal and visceral AT and greater body fat mass and waist circumference, as well as by higher plasma levels of total cholesterol, LDL cholesterol, apolipoprotein (apo)B, and LDL-apoB compared with younger women. Furthermore, middle-aged women showed a greater glycemic response to a 75-g oral glucose load than young women (P < 0.01). In both young and middle-aged subjects, visceral AT accumulation was significantly correlated with plasma triglyceride, apoB, and LDL-apoB levels and with the cholesterol/HDL cholesterol ratio, as well as with plasma glucose, insulin, and C-peptide levels measured in the fasting state and after the oral glucose load, and negatively correlated with HDL cholesterol levels (-0.41 < or = r < or = 0.65, P < 0.05). When variables were adjusted for levels of visceral AT and fat mass, age-related differences that were initially found in plasma apoB and LDL-apoB levels, as well as in fasting glycemia and glucose tolerance, were eliminated. CONCLUSIONS: Results of the present study suggest that even before the onset of menopause there is an age-related deterioration in the metabolic risk profile and an increase in visceral AT deposition in middle-aged women compared with young control subjects. Furthermore, our results provide support for the notion that the age-related increase in visceral AT accumulation is a significant factor involved in the deterioration of the CVD risk profile noted in premenopausal women with age.

Adipose Tissue↗

PubMed1999

Cow level sampling factors affecting analysis and interpretation of milk urea concentrations in 2 dairy herds.

The goals of this study were to determine the influence of the variations among udder quarters, the somatic cell count, the time of sampling during the day, sample conservation, and centrifugation on milk urea (UREA) concentrations, and to propose a sample collection procedure for herds that are not on a Dairy Herd Improvement (DHI) program. Forty cows from 2 herds with different feeding practices were randomly selected. The quarter sampled and the somatic cell count did not significantly influence UREA concentrations. Milk urea concentrations were highest in the morning. The diurnal pattern was not influenced by intrinsic factors like parity, days postpartum, or daily milk yield. The UREA concentrations were significantly higher after refrigeration for one week (mean UREA change = +0.41 +/- 0.24 mmol/L, P = 0.0001) and freezing for one month (mean UREA change = +1.52 +/- 1.25 mmol/L, P = 0.0001). Urea concentrations were slightly higher in lactoserum than in whole milk (mean UREA difference = +0.17 +/- 0.24 mmol/L, P = 0.0001). Although this study included only 2 herds and does not allow extrapolation, differences were found in the diurnal pattern of UREA in these 2 herds, which possibly reflect differences in feeding strategy. With consideration of these results, a 6-point sampling procedure for herds that are not on a DHI program is proposed.

Animals↗

PubMed1999

Regional and gender variations in adipose tissue lipolysis in response to weight loss.

Catecholamine-induced lipolysis was investigated in 32 obese subjects (14 men and 18 premenopausal women), aged 36-50 years, whose body mass index ranged from 30 to 42 kg/m(2). Isolated subcutaneous (subc) abdominal and femoral adipocytes were studied before and after a 15-week weight reducing program, during which mean body weight loss averaged 9 vs. 10 kg in women and men, respectively (P < 0.0001). Participants were re-examined when they were weight-stable. Fat cell weight decreased by about 15;-20% in both depots (P values ranging from 0.01 to 0.05). Epinephrine (mixed alpha2-/beta-adrenoceptor (AR) agonist) induced antilipolysis at low concentrations and a net lipolytic response at higher doses, irrespective of subjects' fatness and anatomic location of fat. Basal lipolysis, maximal lipolytic responses to isoprenaline (beta-AR agonist), dobutamine and procaterol (beta1- and beta2-AR agonists, respectively) as well as maximal antilipolytic effects of epinephrine or UK-14304 (alpha2-AR agonist) were similar before and after weight reduction. However, both beta- and beta2-AR lipolytic sensitivities and the beta-AR density were increased in both genders after weight reduction, this effect being more marked in subc abdominal than in femoral adipocytes (P values ranging from 0.001 to 0.05). The alpha2-AR antilipolytic sensitivity was reduced in adipose cells from both regions in women, but only in subc abdominal adipocytes in men (P < 0.05), although the alpha2-AR density remained unchanged after weight reduction. In conclusion, a moderate weight loss leads to a higher adipose cell lipolytic efficiency which is associated with changes at receptor levels (mainly an increased beta2- and a decreased alpha2-AR sensitivities), in both genders.

Adenosine Deaminase↗

PubMed1999

Effect of cow-specific factors and feeding frequency of concentrate on diurnal variations of blood metabolites in dairy cows.

OBJECTIVE: To determine the effect of feeding frequency and cow-specific factors on diurnal variations of blood metabolites concentrations. ANIMALS: 40 dairy cows from 2 herds. PROCEDURE: Each herd was fed concentrate at a specific feeding frequency (automatic vs twice daily). Blood samples were collected 4 times daily. Plasma concentrations of glucose, nonesterified fatty acids (NEFA), and beta-hydroxybutyrate (BHBA) were analyzed, and concentrations of urea, cholesterol, and total protein (TP) were determined in serum samples. A multivariate repeated-measures ANOVA was used to test the effect of time, feeding frequency, production group, parity, days after parturition, and daily milk yield on diurnal variations of metabolites. RESULTS: Concentrations of glucose, BHBA, and urea remained relatively constant in the herd that was fed by use of automatic distribution of concentrate; however, significant diurnal patterns were detected in the herd fed only twice daily. Only slight differences in glucose and urea concentrations were detected between high- and low-producing cows, but concentration of BHBA was significantly influenced by number of days in lactation. In contrast, diurnal variations in NEFA and cholesterol concentrations were similar between the 2 herds but differed with regard to production group. Concentrations of TP did not have relevant diurnal patterns and did not differ between production groups. CONCLUSIONS AND CLINICAL RELEVANCE: Diurnal variations and feeding frequency affect glucose, BHBA, and urea concentrations in cows. In contrast, concentrations of NEFA, cholesterol, and TP appear to be less sensitive to time of sample collection. Feeding frequency, composition of feed, or both, have a major impact on blood metabolites concentrations.

3-Hydroxybutyric Acid↗

PubMed1999

Effects of red pepper on appetite and energy intake.

Two studies were conducted to investigate the effects of red pepper (capsaicin) on feeding behaviour and energy intake. In the first study, the effects of dietary red pepper added to high-fat (HF) and high-carbohydrate (HC) meals on subsequent energy and macronutrient intakes were examined in thirteen Japanese female subjects. After the ingestion of a standardized dinner on the previous evening, the subjects ate an experimental breakfast (1883 kJ) of one of the following four types: (1) HF; (2) HF and red pepper (10 g); (3) HC; (4) HC and red pepper. Ad libitum energy and macronutrient intakes were measured at lunch-time. The HC breakfast significantly reduced the desire to eat and hunger after breakfast. The addition of red pepper to the HC breakfast also significantly decreased the desire to eat and hunger before lunch. Differences in diet composition at breakfast time did not affect energy and macronutrient intakes at lunch-time. However, the addition of red pepper to the breakfast significantly decreased protein and fat intakes at lunch-time. In Study 2, the effects of a red-pepper appetizer on subsequent energy and macronutrient intakes were examined in ten Caucasian male subjects. After ingesting a standardized breakfast, the subjects took an experimental appetizer (644 kJ) at lunch-time of one of the following two types: (1) mixed diet and appetizer; (2) mixed diet and red-pepper (6 g) appetizer. The addition of red pepper to the appetizer significantly reduced the cumulative ad libitum energy and carbohydrate intakes during the rest of the lunch and in the snack served several hours later. Moreover, the power spectral analysis of heart rate revealed that this effect of red pepper was associated with an increase in the ratio sympathetic: parasympathetic nervous system activity. These results indicate that the ingestion of red pepper decreases appetite and subsequent protein and fat intakes in Japanese females and energy intake in Caucasian males. Moreover, this effect might be related to an increase in sympathetic nervous system activity in Caucasian males.

Adult↗

PubMed1998

An epidemiological study of calcium metabolism in non-paretic postparturient Holstein cows.

Data from 1021 lactations of non-paretic Holstein cows followed in 14 Québec dairy herds were used to describe calcium 'metabolism' after calving in healthy cows. Serum total calcium, phosphorus, magnesium, potassium, albumin, and glucose were measured on the first and seventh days post-calving. The distributions were described and compared between the first and seventh day postpartum. The relationships between serum calcium on the one hand and the other serum metabolites and the cow's age on the other hand were assessed using a general linear model. Serum calcium and phosphorus values were lower on the first day postpartum than a week later (2.03 +/- 0.26 vs 2.26 +/- 0.18 mmol/l, 1.78 +/- 0.48 vs 1.93 +/- 0.39 mmol/l, respectively), whereas it was the opposite for glucose, magnesium, and potassium (3.98 +/- 0.95 vs 3.12 +/- 0.60 mmol/l, 1.01 +/- 0.35 vs 0.95 +/- 0.13 mmol/l, 4.84 +/- 0.40 vs 4.69 +/- 0.38 mmol/l, respectively). Albumin values were similar (25.7 +/- 3.3 vs 25.2 +/- 3.4 g/l). On the first day postpartum, serum calcium was associated in a curvilinear fashion with age, phosphorus and albumin. It also was associated, but to a lesser extent, with glucose and magnesium, whereas it was not associated with potassium. On the seventh day postpartum, calcium was associated with age, phosphorus and with an increased importance of albumin. The results are discussed with regard to postpartum hypocalcemia, the interpretation of serum metabolite values after calving, and the use of the physiological stress at calving. We concluded that (1) postpartum hypocalcemia was an event to be expected, especially for the older cow, (2) a multivariable approach should be used to interpret biochemical profiles after calving, and (3) such profiles could be used to better assess the cow's health.

Aging↗

PubMed1998

Ligand-independent activation of the estrogen receptors alpha and beta by mutations of a conserved tyrosine can be abolished by antiestrogens.

It has recently been suggested that mutation of a conserved tyrosine to asparagine within the ligand-binding domain of the estrogen receptor (ER) alpha confers hormone-independent activation and insensitivity to antiestrogens (Q. X. Zhang et al., Cancer Res., 57: 1244-1249, 1997). In view of the recent discovery of ERbeta and the development of the novel nonsteroidal antiestrogen EM-800 and its active metabolite EM-652, we decided to reexamine this issue by introducing a series of mutations at the conserved tyrosine 537 in ERalpha and 443 in ERbeta and measuring their transcriptional activity in the absence and presence of estradiol and the antiestrogens EM-652, ICI 182,780, and 4-hydroxytamoxifen. As demonstrated previously for ERalpha, we observed that substituting a serine or asparagine but not a phenylalanine for the conserved tyrosine 443 in ERbeta confers constitutive transcriptional activity to the receptor. This activity was apparent on both the vitA2-ERE and the pS2 promoters in Cos-1 and HeLa cell lines as well as the human breast cancer cell line MDA-MB-231. However, the ligand-independent transcriptional activity of all ERalpha and ERbeta mutants examined, including the tyrosine to asparagine substitutions, was completely abolished by the three antiestrogens tested in this system. Furthermore, hormone-independent interaction of ERalpha and ERbeta mutant receptors with the steroid receptor coactivator-1 was abrogated by these antiestrogens. Our report, therefore, indicates that antiestrogens would be effective agents against constitutively active tyrosine ERalpha and ERbeta mutants and suggests that this particular type of modified receptors are unlikely to contribute to resistance toward antiestrogens in breast cancer therapy.

Animals↗

PubMed1998

Effects of red pepper added to high-fat and high-carbohydrate meals on energy metabolism and substrate utilization in Japanese women.

The effects of dietary red pepper added to high-fat (HF) and high-carbohydrate (HC) meals on energy metabolism were examined in thirteen Japanese female subjects. After ingesting a standardized dinner on the previous evening, the subjects took an experimental breakfast (1883 kJ) under the following four conditions: HF meal, HF and red-pepper (10 g) meal, HC meal, or HC and red-pepper meal. Palatability of the experimental meals was measured immediately after the meals. Expired air was collected before and for 210 min after the meal to determine energy expenditure and macronutrient oxidation. Diet-induced thermogenesis was significantly higher after the HC meals than after the HF meals. Lipid oxidation was significantly lower and carbohydrate oxidation was significantly higher after the HC meals than after the HF meals. Addition of red pepper to the experimental meals significantly increased diet-induced thermogenesis and lipid oxidation, particularly after the HF meal. On the other hand, carbohydrate oxidation was significantly decreased by the addition of red pepper to the experimental meals. Addition of red pepper to the HC meal increased the perceived oiliness of the meal to the same level as that of the HF meals. These results indicate that red pepper increases diet-induced thermogenesis and lipid oxidation. This increase in lipid oxidation is mainly observed when foods have a HF content whereas the increase in the perceived oiliness of the meal was found under the HC meal conditions.

Adult↗

PubMed1998

Dietary fat composition and human adiposity.

OBJECTIVES: This study was undertaken to investigate the relation between dietary fat composition and adiposity in adult men. SUBJECTS: A sample of 128 male subjects who participated in Phase 2 of the Québec Family Study. DESIGN: The association between adiposity and total dietary fat intake (TFI), saturated fat intake (SFA), monounsaturated fat intake (MUFA) and polyunsaturated fat intake (PUFA) was analyzed in the overall sample. A comparison of body fatness was also performed between consumers of high (4th quartile) and low amounts (1st quartile) of TFI, SFA, MUFA and PUFA. RESULTS: Significant positive correlations were found between the percentage of dietary energy as total fat and body fatness. Men in the upper quartile of TFI displayed significantly more adiposity than those in the lower quartile. Significant differences were also observed when quartiles were established using SFA and MUFA. However, higher intakes of PUFA had no statistical effects on adiposity. CONCLUSION: These results confirm the notion that high fat diets might lead over time to excess body fat deposition. SFA and MUFA intake also seem to be predictors of actual adiposity markers while high PUFA intake seems to exert no effect on these markers.

Adipose Tissue↗