The effects of a low-carbohydrate diet vs. a low-fat diet on novel cardiovascular risk factors: a randomized controlled trial.
50
2015
"The effects of a low-carbohydrate diet vs. a low-fat diet on novel cardiovascular risk factors: a randomized controlled trial. T Hu, L Yao, K Reynolds et al. Nutrients. 2015 Sep 17;7(9):7978-94. "
US
1
"Increasing evidence supports a low-carb diet for weight loss and improvement in traditional CVD markers. Effects on novel CVD markers remain unclear. Aim: to examine the effects of a low-carb diet vs a low-fat diet on biomarkers for inflammation, adipocyte dysfunction, and endothelial dysfunction. "
148
118
24%
127
12 mo
Y
"Enrolled n=148 obese adults mean age: 46.8y gender: 11.5% men race: 51% African American, 45% white, 2% Hispanic Completed n=118 (79.7%)"
103
"Low-carb diet vs. low-fat diet. Both groups received: - individual counseling initially, then small group counseling specific to diet, less often (1x month) last 6 months - behavioral curriculum - education on benefits of MUFAs and eliminating transfats; fiber - optional meal replacements (bar or shake) - instrutions to maintain baseline activity level"
N
"Low-carb (LC) diet Targets: E: no restriction Carb (net carb): <40g/d Protein: no target Fat: no target Reported intake: E: 1448kcal/d Carb: 127g/d; 34.0%E Protein: 23.6%E Fat: 69.0%E; saturated fat 23.3%"
"Target: NR Intake: 34.0%"
"Target: NR Intake: 69.0%"
"Low-fat (LF) diet based on national guidelines Targets: E: no restriction Carbs: no restriction Fat: <30%E: saturated fat <7%E Reported intake: E: 1527kcal/d Carb: 198g/d; 54.0%E Protein: 18.6%E Fat: 29.8%E; saturated fat 15.5%"
"Primary: adipocytokines, and biochemical markers of inflammation and endothelial biomarkers. Secondary: NR"
LC diet was favored for improving some biomarkers (adiponectin, ICAM-1). On other biomarkers, the two diets did not differ. LF diet was not favored for any of the biomarkers.
NR
*
*
NR
*
*
NR
*
*
NR
*
*
NR
*
*
NR
*
*
*
*
NR
*
*
NR
*
*
NR
*
*
NR
*
*
NR
*
*
"IL-6 & IL-8; TNF-a WG: NR BG: N "
*
*
NA
NR
"Nearly 80% retained in study at 12 mo. Adherence NR"
"Adiponectin WG: Y BG: Y Baseline→12mo LC diet: +31.0% LF diet: +15.7% BG SS p=0.00 ICAM-1 WG: Y BG: Y Baseline→12mo LC diet: +0.05% LF diet: +8.4% BG SS p=0.031 Adipocytokines leptin & resistin; endothelial markers VCAM-1, E-selectin BG NSS "
Findings suggest a 12mo LC diet "results in more favorable changes than a LF diet in adiponectin and ICAM-1 concentrations, and does not differ from a LF diet in reducing other adipocytokines or biochemical markers of endothelial dysfunction in an obese adult population. The two diets had equivalent effects on IL-6, IL-8, and TNF-α concentrations. These findings as a whole suggest that a LC diet is equivalent to, or more effective than, a LF diet for improving some novel CVD risk factors."
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