Browsing by Author "Ravussin, Eric"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Adipose tissue expression of adipose (WDTC1) gene is associated with lower fat mass and enhanced insulin sensitivity in humans
    (2013) Galgani Fuentes, José; Kelley, David E.; Albu, Jeanine B.; Krakoff, Jonathan; Smith, Steven R.; Bray, George A.; Ravussin, Eric
  • No Thumbnail Available
    Item
    Baseline body fat percentage is associated to weight and fat mass gain from high-fat overfeeding over 8 weeks
    (2025) Galgani Fuentes, José; Fernández Verdejo, Rodrigo; Bray, George A.; Smith, Steven R.; Ghosh, Sujoy; Javvadi, Pravalika; Ravussin, Eric
    Background & aims: Epidemiological data suggest that participants with lower vs. higher body mass index (BMI) resist exposure to the obesogenic environment. To test this, we analyzed the relationship between overfeeding-induced weight and fat mass gains with baseline BMI and body fat percentage.Methods: In this controlled intervention study, 34 men (age: 26±5 y old; BMI: 25.5±2.4 kg/m2, body fat [DXA]: 19.3±5.1%) consumed for 8 weeks 40% more energy than needed at weight maintenance. The energy costs of weight and fat mass gain were calculated as the 8-week excess energy consumed divided by weight or fat mass gain. Energy expenditure (baseline and after overfeeding) was determined using a metabolic chamber and doubly labeled water. Transcriptomic analysis was conducted from abdominal subcutaneous adipose tissue samples.Results: Body weight increased 7.2±2.1 kg and fat mass 4.0±1.4 kg. There was no statistical association between baseline BMI and weight and fat mass gains. However, baseline body fat percentage was significantly associated with weight (r=0.57) and fat mass (r=0.59) gains. Body fat percentage was also statistically associated with energy cost of weight (r=-0.38) and fat mass (r=-0.40) gains. Metabolic adaptation in energy expenditure (adaptive thermogenesis) was unrelated to the energy cost of weight and fat mass gains. Transcriptomics analysis showed that high energy cost of weight gain was associated with up-regulation of inflammation-related pathways.Conclusion: Body fat percentage at baseline was inversely associated with overfeeding-induced weight and fat gain resistance. The underlying compensatory response appears unrelated to changes in energy expenditure
  • Thumbnail Image
    Item
    Contribution of brown adipose tissue to human energy metabolism
    (2019) Fernández Verdejo, Rodrigo; Marlatt, Kara L.; Ravussin, Eric; Galgani Fuentes, José
  • No Thumbnail Available
    Item
    Effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT 4 protein, and perilipin protein expression
    (2023) Bajpeyi, Sudip; Apaflo, Jehu N.; Rosas, Victoria; Sepulveda-Rivera, Keisha; Varela-Ramirez, Armando; Covington, Jeffrey D.; Galgani, Jose E.; Ravussin, Eric
    PurposeSmaller lipid droplet morphology and GLUT 4 protein expression have been associated with greater muscle oxidative capacity and glucose uptake, respectively. The main purpose of this study was to determine the effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT4, perilipin 3, and perilipin 5 expressions.MethodsTwenty healthy men (age 24.0 & PLUSMN; 1.0 years, BMI 23.6 & PLUSMN; 0.4 kg/m(2)) were recruited for the study. The participants were subjected to an acute bout of exercise on a cycle ergometer at 50% VO(2)max until they reached a total energy expenditure of 650 kcal. The study was conducted after an overnight fast. Vastus lateralis muscle biopsies were obtained before and immediately after exercise for immunohistochemical analysis to determine lipid, perilipin 3, perilipin 5, and GLUT4 protein contents while GLUT 4 mRNA was quantified using RT-qPCR.ResultsLipid droplet size decreased whereas total intramyocellular lipid content tended to reduce (p = 0.07) after an acute bout of endurance exercise. The density of smaller lipid droplets in the peripheral sarcoplasmic region significantly increased (0.584 & PLUSMN; 0.04 to 0.638 & PLUSMN; 0.08 AU; p = 0.01) while larger lipid droplets significantly decreased (p < 0.05). GLUT4 mRNA tended to increase (p = 0.05). There were no significant changes in GLUT 4, perilipin 3, and perilipin 5 protein levels.ConclusionThe study demonstrates that exercise may impact metabolism by enhancing the quantity of smaller lipid droplets over larger lipid droplets.
  • Thumbnail Image
    Item
    Metabolic flexibility to lipid availability during exercise is enhanced in individuals with high insulin sensitivity
    (2018) Fernández Verdejo, Rodrigo; Bajpeyi, Sudip; Ravussin, Eric; Galgani Fuentes, José
  • Thumbnail Image
    Item
    Skeletal Muscle Perilipin 3 and Coatomer Proteins Are Increased following Exercise and Are Associated with Fat Oxidation
    (2014) Covington, Jeffrey D.; Galgani Fuentes, José; Moro, Cedric; La Grange, Jamie M.; Zhang, Zhengyu; Rustan, Arild C.; Ravussin, Eric; Bajpeyi, Sudip