Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet.

Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. JS Volek, SD Phinney, CE Forsythe et al. Lipids 2009;44:297-309.
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"To test the hypothesis that a carb-restricted diet can simultaneously improve the cluster of markers for metabolic syndrome, which can be understood as a carbohydrate-sensitive mechanism. To investigate the impacts of a low-carb diet on metabolic syndrome, compared to a LF diet."
12 weeks
"Aim of diet was to induce a low level of ketosis Targets E: ~1500kcal/d Carb: 12%E Protein: 28%E Fat: 59%E Intake E: 1504kcal/d Carb: 44.8g/d, 12.4%E Protein: 104.8g/d; 28.1%E Fat: 100.2g/d, 58.9%E (36.4g/d saturated fat)"
"Lowfat diet Subjects instructed on foods allowed and to avoid. Targets E: ~1500kcal/d Carb: ~55%E Protein: ~20%E Fat: ~24%E (10%E from saturated fat; <300mg cholestrol/d). Intake E: 1478kcal/d Carb: 208.3g/d, 55.8%E Protein: 71.5g/d; 19.6%E Fat: 40.0g/d, 23.8%E (11.7g/d saturated fat)"
"Primary: markers of metabolic syndrome - lipid levels, HDL:total C ratio, fasting insulin, FBG, insulin area under the curve (AUC); weight, BMI and body composition, insulin sensitivity. Secondary: markers of CVD risk - postprandial lipemia, Apob:ApoA ratio, LDL particle distribution, serum retinol binding protein 4 (linked to insulin-resistant states)."
"HOMA WG: NR BG: Y Baseline→12 weeks LC diet 2.9→1.3 LF diet 1.7→1.4 BG SS p=0.009 "
"ApoB:ApoA-1 ratio: worsened on LF diet, improved on LC diet. BG SS p=0.001. Leptin (3 measures): On all 3, the LC diet lowered leptin to a SS greater degree than LF diet. BG SS p varied. Total saturated fat acids reduced 57% in LC diet vs 24% in LF diet. LDL particle patterns: the LC diet improved particle size (larger) and reduced the amount of small and very smal LDL particles, SS BG. "
"...a diet restricted in carblhydrate can provide a more comprehensive improvement in the clinical risk factors associated with MetS than a LF diet at reduced caloric intake. ... carbohydrate restriction has the ability to target the range of markers [for MetS] with a single intervention. That this collection of ... markers responds in concert to carbohydrate restriction provides support for considering them as a single syndrome ... Low-carbohydrate diets therefore represent an alternative strategy for general health beyond weight regulation."


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


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