Metabolic effects of weight loss on a very-low-carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects.
22
2008
Metabolic effects of weight loss on a very-low-carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects. J Tay, GD Brinkworth, M Noakes et al. Journal of the American College of Cardiology 2008;51(1):59-67.
Australia
1
"Despite the popularity of very-low-carbohydrate, high-fat (VLCHF) diet, no studies have compared the chronic effects of weight loss and metabolic change to a conventional high-carbohydrate, low-fat (HCLF) diet under isocaloric conditions. Aim: to compare the effects of an energy-reduced, isocaloric VLCHF diet vs a HCLF diet on weight loss and CVD risk outcomes."
109
88
11%
40
24 weeks
N
88
"VLCHF diet Targets E: E-restriction of ~30%. Total: ~6000kJ/1434kcal per day for women; ~7000kJ/1673kcal per day for men. Carb: 4%E, <20g/d first 8 wks; after which allowed to increase to <40g/d Protein: 35%E Fat: 61%E; <8% saturated fat Intake: NR "
"HCLF diet Targets E: E-restriction of ~30%. Total: ~6000kJ/1434kcal per day for women; ~7000kJ/1673kcal per day for men. Carb: 46%E Protein: 24%E Fat: 30%E; <8% saturated fat Intake: NR"
"Primary: weight, BMI, and metabolic effects Blood pressure, FBG, lipids, insulin, apoliporprotein B (apoB), C-reactive protein (CRP), and ketones "
"Weight loss, blood pressure, glucose, CRP and insulin reduced similarly with the two diets. HDL-C and TG improved SS more with the VLCHF diet. LDL-C decreased SS more with the HCLF diet; remained unchanged with the VLCHF diet. However, there was a high degree of variability in LDL-C response in the VLCHF diet group, with 24% reporting an increase of at least 10%. ApoB levels were unchanged in both diet groups."
"HOMA-IR WG: Y BG: N Improved SS in both diets BG NSS VLCHF diet: -0.81 WG SS p<0.001 HCLF diet: -0.97 WG SS p<0.001 BG NSS "
1
0
"C-reative protein WG: Y BG: N Improved SS in both diets BG NSS VLCHF diet: -1.11mg/l WG SS p<0.001 HCLF diet: -1.27mg/l WG SS p<0.001 BG NSS "
1
0
NR
NR
"Dropout rates were similar between groups. Ketone levels in the VLCHF diet group peaked at 8 wks, then declined thereafter but remained twice that for HCLF diet group, indicating compliance, and correlating inversely with reported carb intake."
"ApoB Decreased in both groups but NSS WG or BG."
Weight loss correlated with caloric intake and was not SS different between diet groups. "Overall, although both diets had similar improvements for a number of metabolic risk markers, a HCLF diet had more favorable effects on the blood lipid profile. This suggests that the potential long-term effects of the VLCHF diet for CVD risk remain a concern and that blood lipids should be monitored."
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