title: Higher visceral adiposity is associated with an enhanced early thermogenic response to carbohydrate-rich food.
abstract: BACKGROUND
  Studies examining the dynamics of the thermic effect of feeding (TEF) of specific food items and the relationship of TEF to visceral adiposity are limited.
  
  
  METHODS
  We measured resting energy expenditure (REE) and early-TEF (40-min postprandial, e-TEF) after 8-h fast by indirect calorimetry in 40 obese men, and imaged abdominal fat tissues by magnetic resonance imaging. Each participant was examined on two occasions, 3-weeks apart. At each examination we measured fasting REE and then postprandial REE following the isocaloric [∼380 kcal] consumption of either 56 gr walnuts [(8% carbohydrates; 84% fat, of which 72% polyunsaturated fat)], or 5-slices (150gr) of whole-grain bread (48% carbohydrates; 32% fat). e-TEF was calculated as the area under the curve between the fasting and postprandial tests.
  
  
  RESULTS
  Participants had a mean age of 45 ± 8 years, body-mass-index (BMI) = 31.1 ± 3.8 kg/m(2), total abdominal fat area = 901.4 ± 240 cm(2), visceral fat area (VAT) = 260 ± 102.9 cm(2), fasting REE = 1854 ± 205 kcal, REE/kg = 19.39 ± 1.73 kcal/kg, and respiratory quotient (RQ, CO2 eliminated/O2 consumed) = 0.82 ± 0.04. Individuals who exhibited increased e-TEF (top ΔAUC median) to bread had higher VAT (299 cm(2) vs. 223 cm(2); p = 0.024) and higher BMI (32.4 kg/m(2) vs. 30.0 kg/m(2); p = 0.013), compared to their peers with the lower e-TEF response (ΔAUC below median). As expected, postprandial e-TEF was higher after whole-grain bread consumption [ΔAUC = +14 kcal/40min] compared to walnuts [ΔAUC = -2 kcal/40 min; p < 0.001].
  
  
  CONCLUSIONS
  Higher early thermic effect of high-carbohydrate food, likely reflecting digestion, early absorption and/or sympathetic tone (rather than metabolic utilization (oxidation)), associates with visceral adiposity. Future studies are required to determine if this association represents an added causality between early carbohydrate processing and visceral fat accumulation.
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Yftach
authors.initials: Y
authors.lastname: Gepner
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Nitzan
authors.initials: N
authors.lastname: Bril
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Ilan
authors.initials: I
authors.lastname: Shelef
authors.affiliation: Nuclear Research Center Negev, Dimona, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Schwarzfuchs
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Dana
authors.initials: D
authors.lastname: Serfaty
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Rein
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Noa
authors.initials: N
authors.lastname: Cohen
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Shemesh
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Osnat
authors.initials: O
authors.lastname: Tangi-Rosental
authors.affiliation: Nuclear Research Center Negev, Dimona, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sarusi
authors.affiliation: Nuclear Research Center Negev, Dimona, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Goshen
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Shira
authors.initials: S
authors.lastname: Kenigsbuch
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Yoash
authors.initials: Y
authors.lastname: Chassidim
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Rachel
authors.initials: R
authors.lastname: Golan
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Shula
authors.initials: S
authors.lastname: Witkow
authors.affiliation: Soroka University Medical Center, Beer-Sheva, Israel.
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Henkin
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard School of Public Health, Boston, MA, USA.
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Assaf
authors.initials: A
authors.lastname: Rudich
authors.affiliation: Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. Electronic address: irish@bgu.ac.il.
authors.forename: Iris
authors.initials: I
authors.lastname: Shai
mesh_terms: D050154:Adiposity; D000328:Adult; D001481:Basal Metabolism; D015992:Body Mass Index; D001835:Body Weight; D002153:Calorimetry, Indirect; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage; D002149:Energy Intake; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000378:metabolism*; D019518:Postprandial Period; D022722:Thermogenesis; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference; D000067348:Whole Grains
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D014280:Triglycerides
keywords: Indirect calorimetry; Resting energy expenditure; Specific food items; Thermic effect of feeding; Visceral adiposity