Obesity is associated with impaired endothelial-dependent flow-mediated dilation (FMD), a precursor to hypertension and atherosclerosis.
2
2008
1
"Obesity is associated with impaired endothelial-dependent flow-mediated dilation (FMD), a precursor to hypertension and atherosclerosis. Although dieting generally improves CVD risk factors, the direct effect of different dietary strategies on vascular endothelial function is not known. Aim: to test the hypothesis that a low-fat (LF) diet improves endothelial function compared with an isocaloric low-carbohydrate (LC) diet. "
N
20
"Targets E: 750kcal/d deficit based on individual need Carb: 20g/d Protein: none Fat: none Intake during weight loss phase E: 1855kcal/d Carb: 21.6g/d; 4.66% Protein: 150g/d Fat: 128g/d; 62.1%"
"LF AHA diet Targets E: 750kcal/d deficit based on individual need Carb: not specified Protein: not specified Fat: 30%E Intake during weight loss phase E: 1755kcal/d Carb: 254g/d Protein: 94.0g/d Fat: 45g/d"
"Primary: markers for endothelial function (FMD) Secondary: weight, lipids, SBP, DBP, fasting glucose and insulin, C-reactive protein"
"FMD SS worsened in LC group and SS improved in LF group, but BG NSS. Both groups reduced weight SS and improved SBP, DBP, and fasting insulin, but all BG NSS. Neither diet SS improved FBG, total C, HDL-C, LDL-C or CRP. Only the LC diet SS improved TG; BG NSS."
"WG: N BG: N Neither diet improved SS improved. BG NSS"
0
0
NR
*
*
"WG: N BG: N Neither diet improved SS improved. BG NSS"
0
0
p<0.005
*
*
"WG: N BG: N Neither diet improved SS improved. BG NSS"
0
0
"WG: Y BG: N Baseline→6 wks LC diet 77.9mg/dL→57.5 p<0.02 LF diet 60.6mg/dL→69.3 WG NSS BG NSS "
1
0
*
*
"WG: Y BG: N Improved in both diets Baseline→6 wks LC diet 95.4kg→89.7 p<0.001 LF diet 100kg→96.1 WG SS p<0.001 BG NSS "
1
0
"WG: Y BG: N Improved in both diets Baseline→6 wks LC diet 123.3mmHg→112.6 p<0.05 LF diet 124.1mmHg→115.2 WG SS p<0.05 BG NSS "
1
0
"WG: Y BG: N Improved in both diets Baseline→6 wks LC diet 70.0mmHg→65.8 p<0.05 LF diet 73.2mmHg→66.8 WG SS p<0.05 BG NSS"
1
0
"WG: Y BG: N Improved in both diets Baseline→6 wks LC diet 18.2mg/dL→12.6 p<0.02 LF diet 17.05mg/dL→14.46 WG SS p<0.05 BG NSS"
1
0
NR
*
*
"CRP WG: N BG: N BG NSS"
0
0
NA
NR
"FMD WG: N BG: N SS worsened on LC diet Baseline→6 wks LC diet 8.2%→6.8% -14% WG SS p<0.049 LF diet 6.8%→8.7% +34% WG SS p=0.043 BG NSS "
"Despite similar degrees of weight loss and changes blood pressure, LF diets improved brachial artery flow-mediated dilation over LC diets. LF diets may confer greater cardiovascular protection than LC diets."
Abbreviations:
AHA - American Heart Association;
ALT - alanine aminotransferase;
AMDR - acceptable macronutrient distribution range;
AST - aspartate aminotransferase;
BG - between study groups;
BHOB - beta-hydroxybutyrate;
DBP - diastolic blood pressure;
E- energy, caloric intake;
eGFR - estimated glomerular filtration rate;
FBG - fasting blood glucose;
GGT - gamma-glutamyl transferase;
HDL-C - high-density lipoprotein cholesterol;
iGFR - isotope glomerurar filtration rate;
LDL-C - low-density lipoprotein cholesterol;
NAFLD - non-alcoholic fatty liver disease;
NR - not reported (or data needed for calculation not available);
N - no;
NA - not applicable;
NS - not specified;
NSS - not statistically significant;
SBP - systolic blood pressure;
SS - statistically significant;
TG - triglyceride;
total C - total cholesterol;
V - varied, mixed;
WG - within a study group;
WMD - weighted mean difference;
Y - yes
Number of People in Studies:
3,296 Enrolled in randomized controlled trials on 25% or less carbohydrates
2,626 Completed randomized controlled trials on 25% or less carbohydrates
79.67% 82% completion of studies
Duration of Trial
<6 Months
6-9 Months
1 -2 years
>2 years
# of Trials
36
6
9s
1