Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial.
32
2015
"Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial. J Tay, ND Luscombe-Marsh, CH Thompson et al. American Journal of Clinical Nutrition. 2015 Oct 1;102:780-790."
1
To compare the effects of a very low carb, high unsaturated/low saturated fat diet (VLC) to a high-unrefined carbohydrate, low-fat diet (HC) on glycemic control and CVD risk factors in T2D.
115
93
14%
50
1 yr
Y
"Enrolled: 115 overweight/obese (mean BMI=34.4) adults with T2D. Age: 35-68 years. Completed: 93 (80.9%)"
93
Exercise plus diet intervention with supports: individual biweekly meetings with dietician met individually for 12 weeks and monthly thereafter (dietary advice and instruction on the eating plan and reporting requirements). Subjects supplied key foods (30% total E) for 12 weeks and key foods or food voucher thereafter. Free exercise class (60 min, 3d/week).
Y
"Targets Carb: 14%E; goal - <50g/d Protein: 28%E Fat: 58%E; 35%E MUFA, 13%E PUFA Saturated fat: <10%E Intake: NR"
"Target: 14% Intake: NR"
"Target: 58% Intake: NR"
"High-carb diet Targets Carb: 53%E; emphasis - low-glycemic index foods Protein: 17%E Fat: <30%E; 15%E MUFA, 9%E PUFA Saturated fat: <10%E Intake: NR"
"Diet plans were individualized and matched for E levels with moderate restriction (500–1,000 kcal/day). Diets were designed to include specific foods, which were listed in a food record that participants completed daily. "
"Primary: glycemic control and CVD risk factors HbA1c, glycemic variability (assessed by 48-hour continuous glucose monitoring), diabetes medication changes (antiglycemic medication effects score [MES]), lipids, SBP and DBP, BOHB, urea, creatinine."
The VLC diet overall performed better than the HC diet with SS BG differences for HDL-C, TG, diabetic medication use, and a panel of measures for glycemic variability.
"WG: NR BG: N BG NSS "
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0
"WG: NR BG: N BG NSS Both diets reduced HbA1c by 1%"
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0
"WG: NR BG: N BG NSS"
*
0
"WG: NR BG: Y at 1 yr LC diet: +0.1mmol/L HC diet: +0.06 BG SS p=0.002 "
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1
"WG: NR BG: N BG NSS"
*
0
"WG: NR BG: Y VLC diet: -0.5mmol/L HC diet: -0.1 BG SS p=0.001"
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1
*
*
"Weight, BMI, total fat mass WG: NR BG: N kg VLC diet: -12.0 HC diet: -11.5 BG NSS"
*
0
"WG: NR BG: N BG NSS VLC diet: -11.0mmHg HC diet: -8.7 "
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0
"WG: NR BG: N BG NSS VLC diet: -8.2mmHg HC diet: -6.4 "
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0
"WG: NR BG: N BG NSS VLC diet: -7.7mU/L HC diet: -6.5 BG NSS"
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0
"HOMA2-IR WG: NR BG: N BG NSS VLC diet: -1.1 HC diet: -1.0 BG NSS HOMA2-%B (B cell function) WG: NR BG: N BG NSS VLC diet: -8.8 HC diet: -4.7 "
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0
"C reactive protein WG: NR BG: N BG NSS VLC diet: -0.6 HC diet: -0.6 "
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0
"Antiglycemic medication effects score (MES) WG: NR BG: Y VLC diet: -0.5 HC diet: -0.2 BG SS p=0.003 % of diet group that achieved MES decreases: VLC diet ≥20% decrease - 67.4% ≥50% decrease - 34.8% HC diet ≥20% decrease - 27.7% ≥50% decrease - 17.0% "
No serious adverse events reported. Two VLC diet subjects reported gastrointestinal disorders (constipation and diverticulitis).
Both groups achieved similar completion rates (LC 79%, HC 82%)
"Measures of glycemic variability (eg mean, minimum and maximum glucose; glucose range, amplitude of glycemic excursions, intraday standard deviation): The VLC diet and the HC both improved glycemic variability. However, the VLC diet outperformed the HC diet on all 11, with a SS difference on 10 of them."
"""In conclusion, both the LC and HC diets produced comparable weight loss and improvements in HbA1c and several CVD risk markers. The LC diet had more favorable effects on TG, HDL-C, and glycemic control as shown by lower diabetes medication requirements and greater attenuation of diurnal blood glucose fluctuation. These results suggest that LC diets with high-unsaturated and low-saturated fat contents may be advantageous for T2D management over the long term."" "
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