Limited effect of dietary saturated fat on plasma saturated fat in the context of a low carbohydrate diet.
25
2010
Limited effect of dietary saturated fat on plasma saturated fat in the context of a low carbohydrate diet. CE Forsythe, SD Phinney, RD Feinman. Lipids 2010;45:947-962.
US
1
To determine the relationship between dietary saturated fatty acids (SFA) and plasma SFA; the effect of a weight-stable carb-reduced (CR) diet on plasma arachidonic acid (ARA) and isoprostanes (marker of oxidative stress); and the effect of increased dietary eicosapentaenoic acid (EPA) docosahexaenoic (DHA) acid, as part of a CR diet in mitigating an increase in plasma ARA and associated inflammatory markers.
8
8
12%
UK
"12 weeks (2 6-week feeding periods) Based on knowledge that the fatty acid composition of plasma stabilizes within 4–6 weeks of dietary change [19] and blood lipids stabilize within weeks on a CR diet."
N
8
"CR diet with higher SFA Targets: E: NR Carb: 12%E Protein: NR Fat: 65%E emphasizing SFA Intake: NR"
"CR diet with higher UFA: E: NR Carb: 12%E Protein: NR Fat: 65% emphasizing UFA "
Lipids, fasting glucose and insulin, insulin sensitivity, and inflammatory markers (e.g., Il-6, IL-8, TNF, C-reactive protein).
"Both diets decreased SS TG and SS increased LDL particle size, but did not change LDL-C:HDL-C or TG:HDL ratios. Plasma TG SFA was unchanged in the CR-SFA diet despite a doubling in dietary SFA. Both diets SS reduced palmitoleic acid. The CR-SFA diet SS increased ARA and lowered urine 8-iso PGf relative to ARA. Urine 8-iso PGF2a, a free radical-catalyzed product of ARA, was SS lower than baseline following CRD-UFA (-32%). "
"WG: N BG: N BG NSS"
0
0
"There were no BG SS differences in any of the serum inflammatory markers CRP, IL-6, IL-8, TNF-a, MCP-1, or leptin). Urine 8-iso PGF2a, a free radical-catalyzed product of ARA, was SS lower than baseline following CR diet-UFA (-32%)."
*
0
NR
NR
"""The most striking finding was the lack of association between dietary SFA and plasma SFA. Compared to baseline, a doubling of SFA intake on the CR-SFA diet did not increase plasma SFA in any of the lipid fractions. Findings are consistent with the concept that dietary SFA is efficiently metabolized in the presence of a low-carb diet."""
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