Table 1.
Randomized trials of low-fat versus other dietary interventions of at least 1 year duration among adults, included in the meta-analysis.
| Trial Name | N randomized; Population |
Country | Weight loss goal |
Low-fat diet(s) intervention |
Comparator diet(s) intervention |
Follow- up duration (years) |
|---|---|---|---|---|---|---|
| A to Z (36) | 311; Overweight, premenopausal women |
US | Yes | [1] LEARN (reduced calorie); [2] Ornish (<10% fat; reduced calorie) |
[1] Atkins low-carbohydrate; [2] Zone (30% fat; reduced calorie) |
1 |
| Anderson 1992 (11) |
117; Moderate hypercholesterolemia |
US | Maintain | American Heart Association Phase II (25% fat) |
Usual diet | 1 |
| Barnard 2009 (14) |
99; Type 2 diabetes | US | Yes | Vegan (10% fat) | American Diabetes Association Diet 2003 (30% fat; reduced calorie) |
1.4 |
| Bazzano 2014 (37) |
148; Obese | US | Yes | National Cholesterol Education Program (<30% fat) |
Low carbohydrate | 1 |
| Bertz 2012 (38) | 68; Breastfeeding mothers |
Sweden | Yes | Nordic Nutrition Guidelines (<30% fat; reduced calorie) |
Usual diet | 1 |
| Boyd 1990 (29) | 295; Women at high breast cancer risk |
Canada | Maintain | 15% fat | Canadian Food Guide (No fat intake advice) |
1 |
| Breast Cancer Prevention Program (23) |
194; Women at high breast cancer risk |
US | No | 15% fat | Usual diet | 1 |
| Brehm 2009 (15) |
124; Overweight/obese with type 2 diabetes |
US | Yes | High carbohydrate (25% fat; reduced calorie) |
High mono-unsaturated fat (40% fat; reduced calorie) |
1 |
| BRIDGES (7) | 172; Women with recent breast cancer |
US | No | Nutrition Education Program (20% fat) |
Usual diet | 1 |
| Brinkworth 2009 (39, 40) |
118; At risk for metabolic syndrome |
Australia | Yes | 30% fat (reduced calorie) | Atkins low-carbohydrate (61% fat; reduced calorie) |
1 |
| CALERIE Phase I (41) |
34; Overweight | US | Yes | High glycemic index, food provided (20% fat; reduced calorie) |
Low glycemic index, food provided (30% fat; reduced calorie) |
1 |
| Canadian Diet and Breast Cancer Prevention Study (30) |
4690; Women at high breast cancer risk |
Canada | Maintain | 15% fat | Canadian Food Guide (No fat intake advice) |
10 |
| Dansinger 2005 (42) |
160; At risk for cardiovascular disease |
US | Yes | Ornish (<10% fat) | [1] Atkins low-carbohydrate; [2] Zone (30% fat); [3] Weight Watchers (reduced calorie) |
1 |
| Davis 2009 (16) | 105; Type 2 diabetes | US | Yes | Diabetes Prevention Program diet (25% fat) |
Atkins low-carbohydrate | 1 |
| DEER (12) | 377; Hypercholesterolemia |
US | No | National Cholesterol Education Program (<30% fat) |
Usual diet | 1 |
| The Dietary Alternatives Study (13) |
508; Men with hypercholesterolemia |
US | No | [1] 26% fat; [2] 22% fat; [3] 18% fat |
30% fat | 1 |
| DIRECT (17) | 322; Type 2 diabetes, cardiovascular disease, or obese |
Israel | Yes | American Heart Association (30% fat; reduced calorie) |
[1] Mediterranean diet (35% fat; reduced calorie); [2] Atkins low-carbohydrate |
2 |
| Ebbeling 2007 (43) |
73; Obese young adults |
US | Yes | 20% fat | Low glycemic-index carbohydrates (35% fat) |
1.5 |
| Elhayany 2010 (18) |
259; Type 2 diabetes | Israel | Yes | [1] American Diabetes Association 2003 (30% fat; reduced calorie); [2] Low-fat Mediterranean (30% fat; reduced calorie) |
Low carbohydrate Mediterranean diet (45% fat; reduced calorie) |
1 |
| Esposito 2009 (19) |
215; Type 2 diabetes | Italy | Yes | American Heart Association 2000 (<30% fat; reduced calorie) |
Mediterranean diet (>30% fat; reduced calorie) |
4 |
| Foster 2003 (44) |
63; Obese | US | Yes | 25% fat (reduced calorie) | Atkins low-carbohydrate | 1 |
| Foster 2010 (45) |
307; Obese | US | Yes | 30% fat (reduced calorie) | Atkins low-carbohydrate | 2 |
| Guldbrand 2012 (20) |
61; Type 2 diabetes | Sweden | Yes | <30% fat (reduced calorie) | Low-carbohydrate (50% fat; reduced calorie) |
2 |
| Harvey-Berino 1999 (46) |
80; Overweight/obese |
US | Yes | 20% fat | Low-calorie | 1.5 |
| Iqbal 2010 (21) | 144; Type 2 diabetes, obese |
US | Yes | <30% fat (reduced calorie) | Low-carbohydrate | 2 |
| Keogh 2007 (47) |
44; Overweight/obese |
Australia | Yes | 20% fat (reduced calorie) | Low-carbohydrate (27% fat; reduced calorie) |
1 |
| Klemsdal 2010 (48) |
202; Metabolic syndrome |
Norway | Yes | 30% fat (reduced calorie) | Low glycemic load (35–40% fat; reduced calorie) |
1 |
| Kristal 2005 (49) |
93; Overweight/obese with esophageal metaplasia |
US | Yes | 20% fat (reduced calorie) | Usual diet | 3 |
| Lapointe 2010 (50) |
68; Overweight/obese postmenopausal women |
Canada | Yes | Reduce fat intake | Increase fruits and vegetables |
1.5 |
| Lim 2010 (51) | 113; High cardiovascular disease risk |
Australia | Yes | Food provided (10% fat; reduced calorie) |
[1] Low-carbohydrate, food provided (60% fat; reduced calorie); [2] High unsaturated fat, food provided (30% fat; reduced calorie); [3] Usual diet |
1.25 |
| McAuley 2006 (52) |
96; Women overweight/obese with insulin resistance |
New Zealand |
Yes | Diabetes and Nutrition Study Group of the European Association for the Study of Diabetes (<30% fat) |
[1] low carbohydrate Atkins diet; [2] Zone diet (30% fat) |
1 |
| McManus 2001 (53) |
101; Overweight | US | Yes | 20% fat (reduced calorie) | 35% fat (reduced calorie) | 1.5 |
| Nutrition and Exercise in Women Study (54) |
439; Postmenopausal overweight/obese women |
US | Yes | <30% fat (reduced calorie) | Usual diet | 1 |
| Nutrition and Breast Health Study (31) |
122; Premenopausal women at risk of breast cancer |
US | Maintain | (1) 15% fat; (2) High fruits and vegetables (15% fat) |
(1) Usual diet; (2) High fruits and vegetables |
1 |
| Pilkington 1960 (24) |
58; Men with ischemic heart disease |
UK | No | 20 g fat/day | Increase unsaturated fats | 1.5 |
| Polyp Prevention Trial (25) |
2079; Recent colorectal adenoma |
US | No | 20% fat | Usual diet | 3.1 |
| Pounds Lost Trial (55) |
811; Overweight/obese |
US | Yes | [1] 20% fat (reduced calorie); [2] high protein (20% fat; reduced calorie) |
[1] 40% fat (reduced calorie); [2] high protein (40% fat; reduced calorie) |
2 |
| PREDIMED (26) |
7447; High cardiovascular disease risk |
Spain | No | Reduce fat intake | Mediterranean Diet + [1] increase extra-virgin olive oil intake, [2] mixed nuts intake |
4.8 |
| PREMIER (56) | 810; Prehypertension | US | Yes | DASH (<25% fat; reduced calorie) |
30% fat (reduced calorie) | 1.5 |
| Shah 1996 (57) | 122; Obese women | US | Yes | 20 g fat/day | 30% fat (reduced calorie) | 1 |
| SMART Study (58) |
200; Overweight/obese |
Germany | Yes | German Nutrition Society (30% fat; reduced calorie) |
Low-carbohydrate (35% fat; reduced calorie) |
1 |
| Stern 2004 (59, 60) |
132; Morbidly obese | US | Yes | NHLBI (30% fat; reduced calorie) |
Low-carbohydrate | 1 |
| Swinburn 2001 (28) |
176; Glucose intolerance |
New Zealand |
No | Reduce fat | Usual diet | 5 |
| Tapsell 2004 (22) |
63; Type 2 diabetes | Australia | No | 27% fat | 37% fat | 1 |
| Tehran Lipid and Glucose Study (61) |
100; Overweight/obese |
Iran | Yes | 20% fat (reduced calorie) | 30% fat (reduced calorie) | 1.2 |
| Turner- McGrievy 2007 (62) |
64; Overweight/obese postmenopausal women |
US | Yes | Vegan (10% fat) | National Cholesterol Education Program (<30% fat) |
2 |
| Viegener 1990 (63) |
85; Overweight/obese women |
US | Yes | 15–25% fat (reduced calorie) | 30% fat (reduced calorie) | 1 |
| Women’s Health Initiative Dietary Modification Trial (32) |
48835; Postmenopausal women |
US | Maintain | 20% fat | Usual diet | 7.5 |
| Women’s Health Trial Vanguard Study (27) |
303; Women at high breast cancer risk |
US | No | 20% fat | Usual diet | 2 |
| Women’s Healthy Eating and Living (WHEL) (9) |
3088; Women with previous breast cancer |
US | No | 15–20% fat | USDA guidelines (<30% fat) | 7.3 |
| Women’s Intervention Nutrition Study (WINS) (8) |
2437; Women with breast cancer |
US | No | 15% fat | General counseling on nutritional adequacy |
5 |
| Women’s Intervention Nutrition Study (WINS) Feasibility (10) |
290; Women with postmenopausal breast cancer |
US | No | 20% fat | General counseling on nutritional adequacy |
1.5 |
| Wood 1991 (64) | 294; Overweight/obese |
US | Yes | National Cholesterol Education Program (<30% fat; reduced calorie) |
Usual diet | 1 |