Improvements in vascular health by a low-fat diet, but not a high-fat diet, are mediated by changes in adipocyte biology.
BACKGROUND
Low-fat (LF) and high-fat (HF) weight loss diets improve brachial artery flow-mediated dilation (FMD) in obese individuals, although results are conflicting. Moreover, the role that adipose tissue plays in mediating these diet-related effects are unknown.


OBJECTIVE
This study examined how modulations in FMD by HF and LF diets relate to changes in adipocyte parameters.


METHODS
Obese subjects (n = 17) were randomized to a HF diet (60% kcal as fat) or a LF diet (25% kcal as fat) for 6 weeks. Both groups were restricted by 25% of energy needs.


RESULTS
Body weight decreased (P <0.05) in both groups (HF: -6.6 ± 0.5 kg, LF: -4.7 ± 0.6 kg). Fat mass and waist circumference were reduced (P <0.05) in the LF group only (-4.4 ± 0.3 kg; -3.6 ± 0.8 cm, respectively). FMD improved (P <0.05) in the LF group (7.4 ± 0.8% to 9.8 ± 0.8; 32% increase) and was impaired in the HF group (8.5 ± 0.6% to 6.9 ± 0.7; 19% reduction). Increases in plasma adiponectin (P <0.05, 16 ± 5%), and decreases in resistin (P <0.05, -26 ± 11%), were shown by the LF diet only. Greater decreases in leptin were observed with LF (-48 ± 9%) versus HF (-28 ± 12%) (P <0.05, diet × time). Increased FMD by the LF diet was associated with increased adiponectin, and decreased fat mass, waist circumference, leptin, and resistin.


CONCLUSIONS
Beneficial modulations in vascular health by LF diets may be mediated by improvements in adipocyte parameters.
Department of Kinesiology and Nutrition, University of Illinois, Chicago, Chicago, IL, USA. varady@uic.edu
Krista A
KA
Varady
Surabhi
S
Bhutani
Monica C
MC
Klempel
Shane A
SA
Phillips
D017667:Adipocytes / Q000378:metabolism*; D052242:Adiponectin / Q000097:blood; D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D000704:Analysis of Variance; D001823:Body Composition; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood; D008297:Male; D009765:Obesity / Q000178:diet therapy* / Q000378:metabolism; D011897:Random Allocation; D012307:Risk Factors; D015431:Weight Loss
D052242:Adiponectin; D004041:Dietary Fats; D020738:Leptin
Obesity (Silver Spring). 2009 Sep;17(9):1783-8
19325543
Am J Clin Nutr. 2008 Mar;87(3):567-76
18326593
Endocrinology. 2009 Aug;150(8):3584-93
19359389
J Clin Invest. 1997 Sep 1;100(5):1230-9
9276741
Diab Vasc Dis Res. 2008 Jun;5(2):102-8
18537097
Metabolism. 2009 Dec;58(12):1769-77
19632695
Am J Physiol Heart Circ Physiol. 2008 Oct;295(4):H1514-21
18689498
J Am Coll Cardiol. 2006 Aug 15;48(4):715-20
16904539
J Biol Chem. 2003 Nov 7;278(45):45021-6
12944390
Hypertension. 2008 Feb;51(2):376-82
18195164
Diabetes Care. 2003 Jun;26(6):1927-8
12766136
Br J Nutr. 2007 Oct;98(4):852-9
17490508
Am J Clin Nutr. 2003 Feb;77(2):379-84
12540397
Diabetes. 2000 Nov;49(11):1939-45
11078463
Jpn Circ J. 1998 Jun;62(6):425-30
9652318
PLoS One. 2009 Aug 24;4(8):e6733
19701463
J Hum Nutr Diet. 2004 Oct;17(5):471-80
15357701
J Clin Endocrinol Metab. 2008 Nov;93(11 Suppl 1):S64-73
18987272
J Am Coll Cardiol. 2004 Feb 18;43(4):624-8
14975473
J Intern Med. 2010 May;267(5):452-61
20141567
Am J Clin Nutr. 2009 Aug;90(2):263-8
19515732
Arch Intern Med. 2006 Feb 13;166(3):285-93
16476868
Am Heart J. 2004 Oct;148(4):684-9
15459601
Int J Cardiol. 2010 Jan 7;138(1):3-8
19398137
Int J Obes (Lond). 2008 Dec;32 Suppl 7:S83-92
19136997
J Am Coll Cardiol. 2009 May 26;53(21):1925-32
19460605
J Lipid Res. 1992 Dec;33(12):1833-42
1336027
Am J Physiol Heart Circ Physiol. 2006 Dec;291(6):H2997-3002
16905596