R G Israel

Colorado State University, Fort Collins, Colorado, United States

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Publications (78)277.1 Total impact

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    ABSTRACT: Preventing weight gain in adults and excessive weight gain in children is a high priority. We evaluated the ability of a family-based program aimed at increasing steps and cereal consumption (for breakfast and snacks) to reduce weight gain in children and adults. Families (n = 105) with at least one 8- to 12-year-old child who was at-risk-for-overweight or overweight (designated as the target child) were recruited for the study. Eighty-two families were randomly assigned to receive the family-based intervention and 23 families to the control condition. The 13-week intervention consisted of specific increases in daily steps (an additional 2000 steps/d) and consumption of 2 servings/d of ready-to-eat cereal. The intervention was successful in increasing walking (steps) and cereal consumption. The intervention had positive, significant effects on percentage BMI-for-age and percentage body fat for target children and weight, BMI, and percentage body fat for parents. On further analysis, the positive effects of the intervention were seen largely in target girls and moms, rather than in target boys and dads. This family-based weight gain prevention program based on small changes holds promise for reducing excessive weight gain in families and especially in growing overweight children.
    Obesity 09/2006; 14(8):1392-401. DOI:10.1038/oby.2006.158 · 4.39 Impact Factor
  • Richard G. Israel · Brian D. Butki
    Medicine &amp Science in Sports &amp Exercise 05/2006; 38(5). DOI:10.1249/00005768-200605001-01969 · 4.46 Impact Factor
  • Richard Israel · Brian D. Butki · Elizabeth Mattie
    Medicine &amp Science in Sports &amp Exercise 05/2005; 37(Supplement). DOI:10.1249/00005768-200505001-02241 · 4.46 Impact Factor
  • Richard Israel · Brian D. Butki · Elizabeth Mattie
    Medicine &amp Science in Sports &amp Exercise 05/2005; 37(Supplement):S432. DOI:10.1097/00005768-200505001-02241 · 4.46 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/2001; 33(5). DOI:10.1097/00005768-200105001-00880 · 4.46 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/2001; 33(5). DOI:10.1097/00005768-200105001-01258 · 4.46 Impact Factor
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    ABSTRACT: Epidemiologic studies indicate that alcohol consumption is associated with improved insulin sensitivity; however, scant experimental evidence confirms this observation. To determine the effects of regular moderate wine consumption on insulin sensitivity, 20 overweight women (body mass index [BMI], 29.8 +/- 2.2 kg/m2) participated in a 20-week free-living randomized crossover trial. The subjects, serving as their own controls, consumed wine (190 mL red wine, 13% vol/vol ethanol, 5 days per week) for 10 weeks and abstained for 10 weeks or vice versa. The dependent variables (body weight, BMI, percent body fat, blood pressure, fasting blood glucose and insulin, blood lipids, dietary intake, and insulin sensitivity by intravenous glucose tolerance test [IVGTT]) were measured at the pretest, at the 10-week crossover, and at the 20-week completion of the study. Data were analyzed at the pretest and at completion of the wine drinking and abstention periods of the study using ANOVA by order of treatment. Fasting glucose remained unchanged (mean +/- SD; P > .05) throughout the experiment (pretest, drinking, and abstention, 91.1 +/- 9.2, 91.6 +/- 9.1, and 88.5 +/- 11.2 mg/dL), as did the measures of insulin sensitivity, fasting insulin (pretest, drinking, and abstention, 8.6 +/- 3.3, 8.6 +/- 4.1, and 9.1 +/- 4.7 microU/mg) and the insulin sensitivity index (3.60 +/- 2.96, 3.25 +/- 2.17, and 3.30 +/- 1.84). Body composition and blood lipids also remained unchanged (P > .05) during treatment. Moderate wine consumption at this dose in overweight women did not improve or impair insulin sensitivity, nor did it change any of the known correlates of insulin sensitivity, including body weight and composition, blood lipids, and blood pressure.
    Metabolism 12/2000; 49(11):1473-8. DOI:10.1053/meta.2000.17672 · 3.61 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/1999; 31(Supplement). DOI:10.1097/00005768-199905001-00911 · 4.46 Impact Factor
  • Matthew S. Hickey · Richard G. Israel · Robert V. Considine
    Medicine &amp Science in Sports &amp Exercise 05/1999; 31(Supplement). DOI:10.1097/00005768-199905001-02093 · 4.46 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/1999; 31(Supplement). DOI:10.1097/00005768-199905001-01129 · 4.46 Impact Factor
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    ABSTRACT: The purpose of this study was to compare blood markers associated with eccentrically biased exercise and muscle damage, after two bouts of downhill running. Nine active, untrained males performed 2 x 45 min bouts of downhill running (-0.16 radians), at a speed that would elicit 70% of each subjects VO2max, on a level grade; runs were spaced 14d apart (RUN1, RUN2). Blood samples were obtained before, after, and every hour for 12 h after exercise, as well as every 24 h for 5 d, to assess numbers of circulating neutrophils, monocytes, and lymphocytes, serum cortisol, creatine kinase (CK); subjective sensations of delayed onset muscle soreness (DOMS) were monitored. To control for diurnal variation, two weeks prior to the RUN1, subjects had blood draws performed at the same time as would occur after exercise, but did no exercise (CONTROL). During the 5 d after exercise, DOMS and CK were significantly greater (p < 0.05) after RUN1 compared to RUN2 and CONTROL. During the 12 h after RUN1 and RUN2, neutrophils showed similar responses compared to CONTROL. However, neutrophils were significantly elevated at 96 h after RUN1 and 24 h after RUN2. Monocytes were significantly elevated during 5-11 h after RUN1 and RUN2, compared to CONTROL. Cortisol showed a similar significant diurnal decrease for all three conditions during the 12 h following exercise. The significantly lower levels of CK and DOMS seen after RUN2, compared with the initial run is consistent with the literature. The similar changes in neutrophils and monocytes during the 12 h following RUN1 and RUN2, followed by disparate responses over the subsequent 5 d, requires further investigation.
    International Journal of Sports Medicine 08/1998; 19(6):432-7. DOI:10.1055/s-2007-971941 · 2.37 Impact Factor
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    ABSTRACT: We previously reported, in a study of 608 patients, that the gastric bypass operation (GB) controls type 2 diabetes mellitus in the morbidly obese patient more effectively than any medical therapy. Further, we showed for the first time that it was possible to reduce the mortality from diabetes; GB reduced the chance of dying from 4.5% per year to 1% per year. This control of diabetes has been ascribed to the weight loss induced by the operation. These studies, in weight-stable women, were designed to determine whether weight loss was really the important factor. Fasting plasma insulin, fasting plasma glucose, minimal model-derived insulin sensitivity and leptin levels were measured in carefully matched cohorts: six women who had undergone GB and had been stable at their lowered weight 24 to 30 months after surgery versus a control group of six women who did not undergo surgery and were similarly weight-stable. The two groups were matched in age, percentage of fat, body mass index, waist circumference, and aerobic capacity. Even though the two groups of patients were closely matched in weight, age, percentage of fat, and even aerobic capacity, and with both groups maintaining stable weights, the surgical group demonstrated significantly lower levels of serum leptin, fasting plasma insulin, and fasting plasma glucose compared to the control group. Similarly, minimal model-derived insulin sensitivity was significantly higher in the surgical group. Finally, self-reported food intake was significantly lower in the surgical group. Weight loss is not the reason why GB controls diabetes mellitus. Instead, bypassing the foregut and reducing food intake produce the profound long-term alterations in glucose metabolism and insulin action. These findings suggest that our current paradigms of type 2 diabetes mellitus deserve review. The critical lesion may lie in abnormal signals from the gut.
    Annals of Surgery 06/1998; 227(5):637-43; discussion 643-4. · 8.33 Impact Factor
  • M. S. Hickey · K. P. Davy · J. A. Houmard · R. G. Israel
    Medicine &amp Science in Sports &amp Exercise 05/1998; 30(Supplement). DOI:10.1097/00005768-199805001-01054 · 4.46 Impact Factor
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    ABSTRACT: Summary Background Data: We previously reported, in a study of 608 patients, that the gastric bypass operation (GB) controls type 2 diabetes mellitus in the morbidly obese patient more effectively than any medical therapy. Further, we showed for the first time that it was possible to reduce the mortality from diabetes; GB reduced the chance of dying from 4.5% per year to 1% per year. This control of diabetes has been ascribed to the weight loss induced by the operation. These studies, in weight-stable women, were designed to determine whether weight loss was really the important factor. Methods: Fasting plasma insulin, fasting plasma glucose, minimal model-derived insulin sensitivity and leptin levels were measured in carefully matched cohorts: six women who had undergone GB and had been stable at their lowered weight 24 to 30 months after surgery versus a control group of six women who did not undergo surgery and were similarly weight-stable. The two groups were matched in age, percentage of fat, body mass index, waist circumference, and aerobic capacity. Results: Even though the two groups of patients were closely matched in weight, age, percentage of fat, and even aerobic capacity, and with both groups maintaining stable weights, the surgical group demonstrated significantly lower levels of serum leptin, fasting plasma insulin, and fasting plasma glucose compared to the control group. Similarly, minimal model-derived insulin sensitivity was significantly higher in the surgical group. Finally, self-reported food intake was significantly lower in the surgical group. Conclusions: Weight loss is not the reason why GB controls diabetes mellitus. Instead, bypassing the foregut and reducing food intake produce the profound long-term alterations in glucose metabolism and insulin action. These findings suggest that our current paradigms of type 2 diabetes mellitus deserve review. The critical lesion may lie in abnormal signals from the gut.
    Annals of Surgery 05/1998; 227(5):637-644. DOI:10.1097/00000658-199805000-00004 · 8.33 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/1997; 29(Supplement). DOI:10.1097/00005768-199705001-00272 · 4.46 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/1997; 29(Supplement). DOI:10.1097/00005768-199705001-00241 · 4.46 Impact Factor
  • Medicine &amp Science in Sports &amp Exercise 05/1997; 29(Supplement). DOI:10.1097/00005768-199705001-00866 · 4.46 Impact Factor
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    ABSTRACT: Leptin, the product of the ob gene, is elevated in obese humans and appears to be closely related to body fat content. The purpose of the present investigation was to determine the effect of aerobic exercise training on systemic leptin levels in humans. Eighteen sedentary middle-aged men (n = 9) and women (n = 9) who did not differ in aerobic capacity (29.4 +/- 1.2 vs. 27.5 +/- 1.2 ml x kg(-1) x min(-1)) or insulin sensitivity index (3.41 +/- 1.12 vs. 4.88 +/- 0.55) were studied. Fat mass was significantly lower in females vs. males (21.83 +/- 2.25 vs. 26.99 +/- 2.37 kg, P < 0.05). Despite this, fasting serum leptin was significantly higher in the females vs. males (18.27 +/- 2.55 vs. 9.88 +/- 1.26 ng/ml, P < 0.05). Serum leptin concentration decreased 17.5% in females (P < 0.05) after 12 wk of aerobic exercise training (4 day/wk, 30-45 min/day) but was not significantly reduced in males. Fat mass was not altered after training in either group. In contrast, both aerobic capacity (+13% males, +9.1% females) and insulin sensitivity (+35% males, +82% females) were significantly improved subsequent to training. These data suggest that 1) women have higher circulating leptin concentrations despite lower fat mass and 2) exercise training appears to have a greater effect on systemic leptin levels in females than in males.
    The American journal of physiology 04/1997; 272(4 Pt 1):E562-6. · 3.28 Impact Factor
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    ABSTRACT: Leptin, the product of the ob gene, has been reported to be related to body fat in humans (Considine et al. N. Engl. J. Med. 334: 292, 1996). However, little is known about the physiology of this putative satiety signal in humans. The purpose of the present study was to determine whether leptin is related to body fat content in relatively lean endurance-trained adults. In addition, the effect of acute exercise on circulating leptin concentration was studied. Thirteen male runners, whose mean age, height, weight, %fat, and maximal oxygen consumption (VO2max) were 32.2 +/- 2.5 yr, 176.2 +/- 1.6 cm, 71.9 +/- 6.9 kg, 9.7 +/- 0.9%, and 62.9 +/- 2.2 ml.kg-1.min-1, respectively, were studied. Blood samples were obtained after an overnight fast and again immediately after the completion of a 20-mile run at 70% VO2max under controlled environmental conditions. Serum leptin was closely related to fat mass (r = 0.92) in the runners. Acute exercise had no detectable effect on serum leptin levels (PRE = 2.19 +/- 0.32 ng/ml, POST = 2.14 +/- 0.36 ng/ml). These data indicate that, even at a biological extreme of body fat, circulating leptin concentration is closely related to fat content. Furthermore, the data suggest that, in trained individuals with low leptin concentrations, acute exhaustive exercise has no immediate effect on circulating leptin concentration.
    The American journal of physiology 12/1996; 271(5 Pt 1):E938-40. · 3.28 Impact Factor
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    ABSTRACT: Leptin, the product of the ob gene, is an adipose tissue-derived hormone that appears to regulate both satiety and thermogenesis. In the present report, we have reexamined the relationship between circulating leptin concentration and body fat in humans using a more valid measure of adiposity (hydrodensitometry) and have extended these observations to examine the influence of regional body fat distribution and cardiorespiratory fitness. Fasting serum leptin concentration was 6.9 +/- 0.3 ng.ml-1 in males (N = 333) and 15.2 +/- 1.3 ng.ml-1 in females (N = 63). Interestingly, total fat mass did not differ between groups (males 20.5 +/- 0.5 kg; females 20.4 +/- 1.5 kg), suggesting that females have higher leptin levels per unit fat mass. In a multiple regression model, fat mass was the best predictor of serum leptin concentration in males, accounting for 51% of the variance in leptin concentration. In females, percentage body fat was the best predictor of leptin, accounting for 49% of the variance. In both groups, the relationship between leptin and adiposity remained significant after adjusting for age, maximal treadmill time, waist circumference, and fasting insulin concentration. These observations support previous conclusions that circulating leptin is primarily a function of adiposity and demonstrate for the first time that this relationship is independent of fat distribution or cardiorespiratory fitness. The data also suggest that there is a gender dichotomy in the relationship between leptin and body fat mass in humans.
    Biochemical and Molecular Medicine 11/1996; 59(1):1-6. DOI:10.1006/bmme.1996.0056

Publication Stats

2k Citations
277.10 Total Impact Points

Institutions

  • 1996–2006
    • Colorado State University
      • Department of Health and Exercise Science
      Fort Collins, Colorado, United States
  • 1997
    • Thomas Jefferson University
      • Department of Medicine
      Filadelfia, Pennsylvania, United States
  • 1985–1996
    • East Carolina University
      • Human Performance Laboratory
      Гринвилл, North Carolina, United States