A randomized trial of a low-carbohydrate diet vs Orlistat plus a low-fat diet for weight loss.

A randomized trial of a low-carbohydrate diet vs Orlistat plus a low-fat diet for weight loss. WS Yancy, EC Westman, JR McDuffie et al. Archives of Internal Medicine Jan 25 2010;170(2):136-145.
View Study
Compares effects of low-carb ketogenic (LCK) diet vs. low-fat (LF) plus Orlistat supplement diet on body weight, SBP, DBP, lipids, and glycemic control in adults with T2D.
48 weeks
"Targets E: none Carb: <20g/d Protein: none Fat: none Limits on cheese and some types veg's. Advised to increase ~5carbg/d as goal weight neared or to cope with cravings, at level to maintain weight or diminish cravings Intake E 1698kcal/d Carb: 62g/d; 14.6%E Protein: 112.2g/d; 26.4%E Fat: 106.7g/d; 56.6%E"
"Low-fat plus Orlistat supplement (120mg, 3/d) Targets E: individualized, less 500-1000kcal for maintenance Carb: NR Protein: NR Fat: <30%E; saturated fat <10%E, cholesterol <300 mg/d Intake: E: ~1566kcal/d Carb: 186g/d Protein: 78g/dg/d Fat: 56.6g/d"
Primary: weight, SBP, DBP, lipids, and glycemic control.
Results similar except LC diet was more effective in lowering blood pressure
"Low-carb diet 16 patients: 1 (6%) increased dose 13 (81%) decreased dose Low-fat diet 22 patients 1 (5%) increased dose 15 (68%) decreased dose"
"More common in low-carb group: constipation, increased urinary frequency, halitosis, leg muscle cramps. More common in low-fat group: flatus, bowel incontinence, diarrhea. One subject with T2D in the LCK group developed worse proteinuria. serious adverse events that may have been related to the intervention: 1 LCK subject was hospitalized for syncope attributed to excessive anti-hypertension medication and 2 LF subjects were hospitalized for unstable angina. "
"Compared with other trials, adherence was high over the 48 weeks. For example, the mean carbohydrate intake was 62g/d [15%E] at week 48 in the LC group."
"Creatinine: unchanged from baseline for the two diets. Serum urea nitrogen: higher at all 4 time points with the test diet; at 48 weeks - +3.19 vs +1.23. SS p=.01. Total C; HDL ratio: The control diet performed slightly better than test diet but BG NSS. TG:HDL ratio: Test diet performed better but BG NSS."
"A LCK diet led to similar improvements as the LF diet for weight loss, lipid profile, and glycemic control, but was more effective in lowering both systolic and diastolic blood pressure."


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


Join the Low-Carb Action Network to stay informed of our latest news and calls to action.

Don't miss out on the chance to lend your voice for change!

We will never sell or share our mailing list with any other party or organization