Long-term effects of weight loss with a very low carbohydrate and low fat diet on vascular function in overweight and obese patients.
7
2010
"Long-term effects of weight loss with a very low carbohydrate and low fat diet on vascular function in overweight and obese patients. TP Wycherley, GD Brinkworth, JB Keogh et al. Journal of Internal Medicine. 2010 May;267(5):452-61. Epub 2009 Oct 6. "
Australia
1
"To compare the effects of an E-reduced very low-carbohydrate, high saturated fat diet (LC) and an isocaloric high carbohydrate, low fat diet (LF) on endothelial function after 12 months. "
107
49
8%
30
12 mo
Y
"Enrolled n=107 overweight/obese adults Completed n=49 (45.8%) Mean age: ~50y Mean BMI: ~33.6 Gender: 17 males, 32 females "
49
Compared two isocaloric E-restricted diets, VLC diet vs LF diet. Clinic visits supported subjects. Food quantities specified and daily food records completed to help with compliance.
Y
"VLC diet Wks 1-8 Targets E: men ~7000kJ/d (~1673kcal/d); women ~6500kJ/d (~1553kcal/d) Carb: 4%E, <20g/d; 7.6%E Protein: 35%E Fat: 61%E, 20%E saturated fat Wks 9-52 Targets Same as above <40g/d carb allowed Intake: E: 6694kJ/d (~1600kcal/d) Carb: 30.4g/d Protein: 130.4g/d Fat: 102.2g/d; 57.6%E Saturated fat: 37.3g/d"
"Target: 8% Intake: 7.6%"
"61% Intake: 57.5%"
"LF diet Targets E: men ~7000kJ/d (~1673kcal/d); women ~6500kJ/d (~1553kcal/d) Carb: 46%E Protein: 24%E Fat: 30%E Saturated fat: <8%E, <10g/d Intake: E: 6433kJ/d Carb: 166.9g/d Protein: 87.7g/d Fat: 47.4g/d Saturated fat: 11.4g/d "
"Primary: markers of endothelial function - intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), eSelectin - adiponectin - endothelium-derived fibrinolytic factors plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) - flow-mediated dilitation (FMD), pulse wave velocity (PWV) Secondary: lipids, FBG, weight, SBP, SBP, BMI"
"Both diets SS improved FBG, HDL-C, TG, SBP, DBP with BG NSS. Total C, LDL-C, and FMD (-2.1%) worsened SS on LC diet. BG SS. PWV and other markers for endothelial function: most SS improved on both diets with BG NSS differences. However, ICAM-1 only SS improved on LC diet. BG SS. Both diets results in SS reductions in weight and BMI."
"WG: Y BG: N Both diets SS improved. BG NSS Baseline→52 wks LC diet: 5.55mol/L→5.33 WG SS p<0.001 LF diet: 5.56mmol/L→5.27 WG SS p<0.01"
1
0
NR
*
*
"WG: N BG: N Worsened SS on LC diet BG NSS Baseline→52 wks LC diet: 5.4mol/L→6.00 WG SS p<0.05 LF diet: 5.59mmol/L→5.60 WG NSS BG SS p<0.05"
0
0
"WG: Y BG: N Improved SS on both diets BG NSS Baseline→52 wks LC diet: 1.41mol/L→1.69 WG SS p<0.01 LF diet: 1.36mmol/L→1.43 WG SS p<0.01 BG NSS"
1
0
"WG: N BG: N Worsened SS on LC diet Baseline→52 wks LC diet: 3.22mol/L→3.82 WG SS p<0.05 LF diet: 3.46mmol/L→3.48 WG NSS BG SS p<0.05"
0
0
"WG: Y BG: N Improved SS on both diets BG NSS Baseline→52 wks LC diet: 1.70mol/L→1.13 WG SS p<0.001 LF diet: 1.65mmol/L→1.41 WG SS p<0.001 BG NSS"
1
0
*
*
"Weight, BMI WG: Y BG: N Weight at wk 52 LC diet: -14.9kg LF diet: -11.5 BG NSS BMI at wk 52 LC diet: -5.3 LF diet: -3.9 BG NSS "
1
0
"WG: Y BG: N BG NSS Values NR"
1
0
"WG: Y BG: N BG NSS Values NR"
1
0
NR
*
*
NR
*
*
NR
*
*
NA
NR
"Dietary records indicated dietary compliance was consistent with the prescribed dietary patterns."
"FMD WG: N BG: N Worsened (-2.1%) in LC diet but not LF diet PWV WG: Y BG: N improved SS with both diets WG p<0.01 BG NSS Endothelial function PAI-1, tPA, eSelectin, adiponectin WG: Y BG: N improved SS on both diets BG NSS VCAM-1 WG: N (both groups) BG: N BG NSS ICAM-1 WG: Y (improved only on LC diet) BG: Y "
" ... both LC and LF hypoenergetic diets achieved similar reductions in body weight and were associated with improvements in PWV and a number of endothelium- derived factors. However, the LC diet impaired FMD suggesting chronic consumption of a LC diet may have detrimental effects on endothelial function."
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