Table 1.

Weight Losses From Selected Randomized, Controlled Trials That Compared Diets With Varying Macronutrient Compositions

Study	N	No. Lifestyle Sessions Provided	Dietary Intervention	Weight Change	Month	Comment/Other Results
Dansinger et al¹⁴	160 (51% F)	4	Atkins	−2.1 kg^a	12	All participants had hypertension, dyslipidemia, and/or fasting hyperglycemia.
	58% completed		Zone	−3.2 kg^a		There were no significant differences between groups in reductions in CVD risk factors.
			Weight Watchers	−3.0 kg^a
			Ornish	−3.3 kg^a
Das et al¹⁵^*	34 (% F unknown)	52	Low-glycemic load	−7.8%^a	12	No differences were observed between groups in change in CVD risk factors.
	85% completed		High-glycemic load	−8.0%^a
Ditschuneit et al¹⁶^*	100 (79% F)	27	MR	−10.4 kg^b	27	There were significantly greater reductions in total cholesterol and fasting insulin in the group that received meal replacements.
	63% completed		Conventional diet for 3 mo, followed by addition of MR	−7.7 kg^a
Fabricatore et al¹⁷	79 (80% F)	30	Low-glycemic load	−4.5%^a	9	All participants had type 2 diabetes.
	63% completed		Low-fat	−6.4%^a		Larger reductions in HbA_1c in the low-glycemic load group.
Foster et al¹⁸	63 (68% F)	3	Low-carbohydrate (high protein, high fat)	−4.4%^a	12	HDL cholesterol increased more and triglycerides decreased more in the low-carbohydrate group.
	59% completed		Conventional (high-carbohydrate, low-fat)	−2.5%^a		Greater reductions in LDL and total cholesterol in the low-fat group at 3 mo.
Foster et al¹⁹	307 (68% F)	38	Low-carbohydrate	−6.3 kg^a	24	Greater increase in HDL cholesterol in the low-carbohydrate group. Greater decrease in triglycerides at 3 and 6 mo in the low-carbohydrate group. Greater decrease in VLDL at 3, 6, and 12 mo in the low-carbohydrate group and in LDL at 3 and 6 mo in the low-fat group.
	63% completed		Low-fat	−7.4 kg^a
Gardner et al²⁰	311 (100% F)	8	Atkins (low-carbohydrate)	−4.7 kg^a	12	Greater increase in HDL cholesterol in Atkins than Ornish group and greater decrease in triglyceride levels in Atkins than Zone group.
	80% completed		Zone (even distribution)	−1.6 kg^b		Systolic blood pressure decreased more in Atkins than in all other groups. Diastolic blood pressure decreased more in Atkins than in Ornish group.
			LEARN (calorie-restricted)	−2.2 kg^a,b
			Ornish (low-fat)	−2.6 kg^a,b
Iqbal et al²¹	144 (10% F)	27	Low-carbohydrate	−1.5 kg^a	24	All participants had diabetes.
	47% completed		Low-fat	−0.2 kg^a		No differences within or between groups for lipids or glycemic indexes.
Klemsdal et al²²	202 (58% F)	9	Low-glycemic load	−4.0 kg^a	12	62% participants with metabolic syndrome.
	81% completed		Low-fat	−4.3 kg^a		Waist circumference decreased more in low-fat diet group.
						Diastolic blood pressure decreased more in the low glycemic load group.
Li et al²³^*	104 (% F unknown)	15	Individualized diet	−2.4 kg^a	12
	73% completed		Individualized diet+MR	−4.4 kg^a		HbA_1c was significantly lower in MR group with use of repeated measurement analysis.
Sacks et al²⁴	811 (64% F)	66	Low-fat, average-protein (highest carbohydrate)	−2.9 kg^a	24	LDL cholesterol decreased significantly more in lowest-fat/highest carbohydrate than in highest-fat/lowest carbohydrate groups. HDL cholesterol increased more with lowest carbohydrate than with the highest carbohydrate diet.
	80% completed		Low-fat, high-protein	−3.8 kg^a		All diets, except the highest carbohydrate, decreased fasting insulin (greater decrease in the high protein vs average protein diets).
			High-fat, average-protein	−3.1 kg^a
			High-fat, high-protein (lowest carbohydrate)	−3.5 kg^a
Samaha et al²⁵	132 (17% F)	9	Low-carbohydrate	−5.8 kg^a	6	Triglyceride levels decreased more in the low-carbohydrate group than in the low-fat group.
	60% completed		Conventional (low-fat)	−1.9 kg^b		Among diabetic participants, mean fasting glucose level decreased more in the low-carbohydrate group than in the low-fat group.
Shai et al²⁶	322 (14% F)	24	Low-fat	−2.9 kg^a	24	HDL cholesterol increased in all groups, significantly more in the low-carbohydrate than low-fat group.
	85% completed		Mediterranean	−4.4 kg^b		Triglyceride levels decreased more in the low-carbohydrate than in the low-fat group.
			Low-carbohydrate	−4.7 kg^b		In diabetic participants, only the Mediterranean diet group had a decrease in fasting glucose.
Stern et al²⁷	132 (17% F)	15	Low-carbohydrate	−5.1 kg^a	12	Triglyceride levels decreased more in the low-carbohydrate group than in the low-fat group.
	66% completed		Conventional (low-fat)	−3.1 kg^a		HDL cholesterol decreased less in the low-carbohydrate group than in the low-fat group.
						Greater improvements in HbA_1c in type 2 diabetics in the low-carbohydrate group.
Yancy et al²⁸	120 (76% F)	9	Low-fat diet	−6.5 kg^a	6	Low-carbohydrate group showed greater decreases in triglycerides and greater increases in HDL.
	66% completed		Low-carbohydrate, ketogenic diet with nutritional supplements	−12.0 kg^b

All studies were analyzed by use of an intention-to-treat population, with the exception as indicated by an asterisk (*).

Different letters (in superscript) indicate statistically significant differences in weight loss between groups.

F indicates female; LDL, low-density lipoprotein; HDL, high-density lipoprotein; VLDL, very low density lipoprotein; HbA_1c, hemoglobin A_1c; MR, meal replacements; CVD, cardiovascular disease.

A completer’s population was examined.

^†

Results reported as “greater,” “larger,” “increased more,” etc represent statistically significant differences between treatment conditions.