Tracking of adult adiposity in early, average and late maturing children: a thirty year longitudinal growth study.

AIM: To investigate if predictability of adult adiposity is related to maturation status in youth. METHODS: Data of the longitudinal ''LEGS''-study (N = 550) from 6 to 18 years were used. At 35 years, 59 men and 60 women participated again. Early (EM), average (AM) and late (LM) maturity groups were established, using tertiles of age at peak height velocity (JPA-method). Pearson correlations between the childhood and the adult measurements were calculated. RESULTS: Female sum of 4 skinfolds (Sigma4SF) correlations increase from very low/moderate (6-9 years) to high at 11 years (EM), 15 years (AM) and 17 years (LM). The highest predictability was 65.6% for the Sigma4SF at 14 years in EM. At this age, predictability is 30.3% in AM and 0.8% in LM (P < 0.05). In EM, BMI correlations are moderate/high until 14 yrs (r2 = 0.64 at 13 years), but low until 15 years in LM. Male Sigma4SF correlations are very low/moderate in the three maturity groups. Significant correlation was found in the LM at 16 yrs. Moderate Body Mass index (BMI) correlations are reached at 9 years (LM) and 11 years (EM). At 16 years predictability = 4.9% for BMI in LM males. CONCLUSION: Predictability of adiposity at 35 years is generally better in girls than in boys. A dose-response effect of maturity on adult adiposity is found in girls but not in boys. Interventions to prevent adult obesity might be more effective in females than in males, particularly in EM females.

Estimation of daily human intake of food flavonoids.

The daily intake of food flavonoids was determined using a semiquantitative food frequency questionnaire (FFQ) and a four day non consecutive food diary (4DFR) in a group of 45 female Flemish dietitians. The subjects were asked to report their food intake three times: day 1 using the FFQ (FFQ1); between day 2 and 13 using a four day non consecutive food diary (4DFR); and again the FFQ on day 14 (FFQ2). The total flavonoid intake in mg/day as estimated with the different methods were respectively (mean and SD) for FFQ1 166.0 +/- 146.6 mg/day; for 4DFR 203.0 +/- 243.2 mg/day; and for FFQ2 158.3 +/- 151.8 mg/day. There was a significant different estimate for the amount of flavan-3-ols, flavanones and flavones when comparing the two FFQs with the 4DFR. The two research methods classified 88% of the 45 dietitians in the same or in an adjacent quartile for total flavonoid intake. The findings of this study indicate that the developed FFQ seems to be a simple and reliable method to assign subjects in quartiles of flavonoid intake.

Cross-sectional analysis of BMI and some lifestyle variables in Flemish vegetarians compared with non-vegetarians.

Epidemiological studies on vegetarians indicate that appropriately planned vegetarian diets are associated with certain health benefits, which may lower mortality and morbidity. A healthy lifestyle, such as regular physical activity and avoidance of harmful practices, such as smoking and heavy drinking, could also influence these positive health-related outcomes in vegetarians. This study reports BMI, smoking and drinking habits, engagement in physical activity, medication use and subjective health perception in a vegetarian population (women: n = 206, mean age 37.0 +/- 12.3 years; men: n = 120, mean age 42.3 +/- 15.9 years) as compared with a reference Belgian population (women: n = 4993, mean age 49.8 +/- 18.0 years; men: n = 4666, mean age 48.0 +/- 17.1 years). When considering the vegetarian group as a whole, the vegetarians had a lower mean BMI compared with the reference population (respectively 22.1 +/- 3.1 kg/m2 compared with 24.6 +/- 4.8 kg/m2 for women (p < 0.001) and respectively 22.6 +/- 3.6 kg/m2 compared with 25.7 +/- 4.0 kg/m2 for men (p < 0.001)). Vegetarians smoked less than subjects of the reference group (13.5% compared with 28.5% respectively; p < 0.001). During weekdays the percentage of subjects consuming alcoholic drinks in the two populations was comparable (32.8 in the vegetarian and 35.8 in the reference population; p = 0.159). During the weekend, more subjects of the reference population drank alcohol compared with the vegetarian subjects (70.2% vs. 58.6% respectively; p = 0.026). More vegetarians were involved in intensive physical activity (over 4 h per week) compared with the reference population (36.8% vs. 17.3% respectively; p < 0.001), while fewer vegetarians were involved in moderate physical activity (up to 4 h per week) compared with subjects of the reference group (28.2% and 51.0% respectively; p < 0.001). Percentages of subjects involved in no physical activity were comparable in both groups (vegetarians 34.9 vs. reference subjects 31.8; p = 0.625). Use of prescribed medication was lower among the vegetarians (25.5% compared with 47.3% in the reference population; p < 0.001), while use of non-prescribed drugs was comparable between both groups (34.1% in the vegetarian group and 28.2% in the reference group; p = 0.580). More vegetarian subjects perceived their health to be good to very good compared with the subjects of the reference population (90.4% vs. 77.2% respectively; p < 0.001). The significant difference for the BMI values when comparing the vegetarian males and females with the reference population cannot be completely explained by the evaluated lifestyle characteristics. However, the lower BMI values in vegetarians are in agreement with the literature.

Growth, development, and physical fitness of Flemish vegetarian children, adolescents, and young adults.

This study was designed to assess average daily dietary intakes of energy in 82 vegetarian children (group A: 6- 9-y-old girls and 6-11-y-old boys), adolescents (group B: 10- 15-y-old girls and 12-17-y-old boys), and young adults (group C: 16-30-y-old females and 18-30-y-old males) and included determination of height and weight; triceps, suprailiac, and calf skinfold thicknesses; puberty ratings; and physical fitness. Dietary energy intake was lower than recommended values in all 3 groups. Height and weight did not differ significantly from the reference data except in group B, which had significantly lower heights and weights and lower body mass indexes (P<0.05). Triceps and suprailiac skinfold thicknesses were lower in all age groups, whereas the calf skinfold thickness was only significantly lower in the 10-15-y-old girls (P<0.05). The vegetarian children were as physically fit as the reference group. The vegetarian adolescent boys and girls and the young adults scored significantly lower on the standing long jump and 30-s sit-up (P<0.05). The vegetarian subjects of groups B and C recovered significantly faster from the step test (P<0.05). Puberty ratings plotted on percentile graphs showed that all vegetarian subjects, except for 1 girl, were within the normal developmental range. We conclude that, within the limits of this study, vegetarian subjects have lower relative body weights and skinfold thicknesses in adolescence than do nonvegetarians. They scored lower on the strength tests and better on the cardiorespiratory test when compared with reference values. The growth and maturation status of the vegetarian population were within the normal range.

Evaluation of habitual physical activity from a week's heart rate monitoring in French school children.

Habitual physical activity (HPA) was studied in 30 boys and 34 girls aged 6-11 years. All the children performed a shuttle run test (SRT) to assess maximal heart frequency (fcmaxSRT) and to evaluate maximal oxygen uptake (VO2maxSRT). Heart rate (fc) was measured continuously from Monday to Sunday, using a heart rate counter. The time spent at fc greater than 140 beats. min-1 (tfc > 140) and at fc greater than 160 beats. min-1 (tfc > 160) permitted HPA to be evaluated. The daily heart rate (fcd) and the percentage of heart rate reserve (%fcrd) were calculated to evaluate the metabolic activity. In the boys and girls, fcd and % fcrd varied little with age. The metabolic activity varied in a rhythmical way during the week and was higher during school days than during free days (P < 0.001). The children were more active during school days (ds) than during the free days (df). This observation was particularly marked in the boys having tfc > 140 being twice as high during ds compared to df [tfc > 140, ds 85 (SD 25), df 40 (SD 26) min; tfc > 160, ds 36 (SD 19), df 16 (SD 13) min]. During ds tfc > 160 was greater in the boys than in the girls (P < 0.01). The same held for tfc > 140 and % fcrd from the age of 9 years (P < 0.001). It was during the recreation periods that the differences between the boys and the girls were observed (P < 0.01). There was no significant difference between the boys and the girls during lessons, in the evening and during df (% fcrd 26-28%, tfc > 140 35-45 min, tfc > 160 10-18 min). In contrast, the children who were physically active in a sports club, had less spontaneous physical activity and % fcrd, tfc > 140, tfc > 160 and VO2maxSRT were identical to those of the other children.

Mechanical efficiency of the elbow flexors in rowing.

Biomechanical and especially kinesiological investigations of the mechanical efficiency of rowers are rarely found in today's literature. The coach frequently relates to skills or technical movements in terms of their aesthetic appearance rather than their mechanical effectiveness. The force output of the elbow flexors appears to be a function of the forearm position. The literature referring to the mechanical efficiency of the elbow flexors seems to favor both semiprone and supine positions, whereas the prone position appears to be discredited. It is the latter grip position that is actually employed and traditionally accepted in the sport of rowing. In fact, this technique was never challenged or scientifically researched to see whether a modified one might lead to better efficiency. Consequently, the purpose of this investigation was to analyze whether athletes' force output differed if the gripping technique was changed from pronation to a semiprone grip (one arm prone, the other semiprone). Under the specific conditions of this investigation, it was demonstrated that the semiprone position was generating greater force output and higher electrical activity, thus being superior to the classical prone grip.

Indirect evidence against a contribution of the guanine nucleotide-binding inhibitory component of adenylate cyclase to impaired lipolysis in the epididymal adipose tissue of congenitally obese (ob/ob) mice.

The mixed adrenergic agonist epinephrine, at a 10 microM concentration, stimulated cyclic AMP production and glycerol release in the epididymal adipose tissue of ob/ob male mice. These effects when tested, respectively, after 7 min in the presence and after 60 min in the absence of theophylline were, however, 7- and 5-fold lower than in lean controls. The alpha-adrenergic blocker phentolamine and adenosine deaminase (which destroys extracellular adenosine) did not restore a normal lipolytic response to epinephrine in the adipose tissue of ob/ob mice. These data provide indirect evidence against a hyperactive mechanism in the coupling of alpha-adrenergic receptors and adenosine receptors to Ni, the guanine nucleotide-binding inhibitory component of adenylate cyclase, as the cause of reduced lipolysis in the adipose tissue of ob/ob mice.

Force analysis of the rowing stroke employing two differing oar grips.

The velocity of the rowing boat appears to depend on the force which the athlete applies at the handle of the oar. Although force is generated by legs, upper body, and arms, the latter are the only limbs which actually transmit and apply the force against the oar. The force output of the arms seem to be a function of the forearm position used by the athlete while gripping the oar. The traditional gripping technique is with the forearms in pronation. This technique was never challenged or scientifically researched to see whatever a modified one might lead to better efficiency. Consequently, the purpose of this investigation was to analyze whether athletes' force output differed if the gripping technique was changed from pronation to a semiprone grip (one arm prone, the other semiprone). Under the specific conditions of this investigation it was demonstrated that the semiprone position was generating greater force output, thus being superior to the classical prone grip.

Anthropometric characteristics of female Olympic rowers.

Anthropometric data on 51 (23%) of the female rowers in the 1976 Montreal Olympic Games are summarized and compared to a female non-rower athletic sample and to a female Canadian university student sample. The rowers, being taller and heavier (means 174.3 cm and 67.4 kg) tended to be larger in all measures than the reference samples, with the exception that the university students had larger mean skinfold thicknesses. The Heath-Carter somatotype distribution of the rowers (mean 3.1 - 3.9 - 2.8) was compared to that of the students (4.0 - 3.5 - 2.9) and other female athletic samples. Proportionality profiles scaled to a unisex reference human or phantom showed both samples to be rather similar in proportional lengths except for longer tibiale height, wider transverse chest breadth, larger flexed arm and forearm girths, and smaller skinfold thicknesses in female rowers than in students. Fractionation of body mass by a four-component model showed the rowers to have similar percent skeletal and residual masses, lower percent fat and higher percent muscle mass than students. The anthropometric characteristics as described and analyzed in this study are submitted as the basic anthropometric reference for those interested in fostering the development of women's rowing.

Effects of portacaval diversion on lipid metabolism in rat adipose tissue.

Male rats were submitted for 3 wk either to portacaval shunt or to portacaval transposition. In both cases, sham-operated pair-fed rats served as controls. After an overnight fast, insulinemia was similar in all groups, but glucagonemia was significantly higher (by 65%) and serum glucose significantly lower (by 35%) in rats with a portacaval shunt. The lipid metabolism of epididymal adipose tissue was studied in vitro, as well as in vivo. In rats with a portacaval shunt, in vitro lipogenesis from [U-14C]glucose, [1-14C]acetate, or 3H2o was 60-80% lower than in sham-operated pair-fed controls. Twice as much in vitro basal lipolysis could be determined. In addition, in vivo lipogenesis from 3H2O was markedly decreased (6 times). By contrast, in rats with portacaval transposition, in vitro lipogenesis was higher (by 80-140%) and basal lipolysis lower (by 63%) than in pair-fed controls. Thus, even when the nutritional state was taken into consideration, the type of portal diversion was the determining factor in influencing lipid metabolism in epididymal adipose tissue.

Influence of litter size on lipid composition in infant mice.

The amount of milk available to each member of the litter was varied by adjusting the number of mice pups to 4, 8 or 12 per dam. The total fatty acid content of the carcass of the young increased for 2 weeks, and there was more in the well-fed groups. The fatty acid contents decreased thereafter transiently in all groups until weaning. The milk diet contributed major quantities of lauric and myristic acids to peripheral tissues but not to the liver. Undernourishment during neonatal life was associated with a relative reduction in palmitoleic, oleic and linoleic acids in lipids of the carcass. In contrast the carcass of the progeny subjected to overall dietary abundance showed relative increase in palmitoleic, oleic and linoleic acids at the expense of stearic acid.