Search Plan and Results

Evidence Analysis Question

Is the therapeutic use of a vegetarian diet effective for bringing about short-term (less than one year) improvements in weight status in obese and overweight adults?

Is the therapeutic use of a vegetarian dietary pattern effective for bringing about longer-term (more than one year) improvements in weight status in obese and overweight adults?

How do vegetarian diets compare to other therapeutic diets for treating overweight or obese adults?

How do therapeutic vegetarian diets compare to other types of therapeutic diets in terms of attrition rate in adults?

What are some factors associated with attrition rates in studies of adults using vegetarian diets for nutrition therapy?

Date of Literature Review

March 2008

Inclusion Criteria

Inclusion Criteria Template 

Age: Adult.

Setting: Clinical trials, treatment setting.

Health Status: Otherwise healthy.

Nutrition-related Problem/Condition: Obesity or overweight.

Study Design Preferences: Clinical trial (prefer randomized controlled trial).

Size of Study Groups:

The sample size must equal 10 individuals for each study group.

Study Drop-out Rate: Any. (Attrition is noted. Studies with attrition greater than 20% are given less weight in formulating conclusions.)

Year Range: 1989 to 2008.

Authorship

If an author is included on more than one Review Article or primary research article that is similar in content, the most recent review or article will be accepted and earlier versions will be rejected.

If an author is included on more than one Review Article or primary research article and the content is different, then both reviews may be accepted.

Language

Limited to articles in English.

Exclusion Criteria

Health Status: Diseases other than obesity, diabetes type 2, dyslipidemia or fibromyalgia.

Diet: Studies with no vegetarian comparison group (note: "Plant-based" diets are not considered vegetarian unless they specify within the article that the diet includes no meat).

Type of articles: Review, comment, observational (non-intervention) studies.

Search Terms: Search Vocabulary

1. Terms to identify the health condition: obesity,  overweight

2. Terms to identify the intervention: "weight loss, " "weight management, " "Diet, Vegetarian"[Mesh], vegetarian

3. Terms to identify the type of study design: Clinical Trial, Meta-Analysis

Electronic Databases

("Overweight"[Mesh] OR "Obesity"[Mesh]) AND "Diet, Vegetarian"[Mesh] Limits: Entrez Date from 1989/01/01 to 2009/05/01, Humans, Clinical Trial, Meta-Analysis, English, All Adult: 19+ years

13 Hits

13 to review

("Overweight"[Mesh] OR "Obesity"[Mesh]) AND "Diet, Vegetarian"[Mesh] Limits: Entrez Date from 1989/01/01 to 2008/05/01, Humans, English, All Adult: 19+ years

27 Hits

Five additional studies (in addition to those identified above) to review

Overweight and vegetarian; Limits: published in the last 10 years, Humans, English, All Adult: 19+ years

18 Hits

Three studies to review that are unique from above

 

There are 10 results out of 527, 885 records for: Obesity and vegetarian in The Cochrane Central Register of Controlled Trials."

No unique studies identified (different from above searches).

Total articles identified to review from electronic databases: 13

Articles Identified from other sources:

Articles identified from intervention studies with a vegetarian diet for the following topics: diabetes type 2, cholesterol, triglycerides. These studies were included because they included weight status outcomes.

Barnard, ND, Scialli, AR et al. Effectiveness of a low-fat vegetarian diet in altering serum lipids in healthy premenopausal women. Am J of Cardiology. 2000 (Apr); 85: 969-972. 

Barnard, ND., Cohen, J., Jenkins, D., et al. (2006). A low fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Diabetes Care. 29; 1777-1783.  

Bhumisawasdi J, Vanna O, Surinpang N. The self-reliant system for alternative care of diabetes mellitus patients--experience macrobiotic management in Trad Province. J Med Assoc Thai. 2006 Dec; 89(12): 2104-2115

Daubenmier JJ, Weidner G, Sumner MD, Mendell N, Merritt-Worden T, Studley J, Ornish D. The contribution of changes in diet, exercise, and stress management to changes in coronary risk in women and men in the multisite cardiac lifestyle intervention program. Ann Behav Med. 2007 Feb; 33(1): 57-68.

de Mello VD, Zelmanovitz T, Perassolo MS, Azevedo MJ, Gross JL. Withdrawal of red meat from the usual diet reduces albuminuria and improves serum fatty acid profile in type 2 diabetes patients with macroalbuminuria. Am J Clin Nutr. 2006 May; 83(5): 1032-1038.

Jenkins DJ, Kendall CW, Marchie A, Faulkner DA, Wong JM, de Souza R, Emam A, Parker TL, Vidgen E, Lapsley KG, Trautwein EA, Josse RG, Leiter LA, Connelly PW. Effects of a dietary portfolio of cholesterol-lowering foods vs. lovastatin on serum lipids and C-reactive protein. JAMA. 2003 Jul 23; 290(4): 502-510.

Jenkins DJ, Kendall CW, Marchie A, Faulkner D, Vidgen E, Lapsley KG, Trautwein EA, Parker TL, Josse RG, Leiter LA, Connelly PW. The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia. Metabolism. 2003 Nov; 52(11): 1478-1483.

Kestin, M, Rouse, IL, Correll, RA, Nestel, PJ. Cardiovascular disease risk factors in free-living men: Comparison of two prudent diets, one based on lactoovovegetarianism and the other allowing lean meat. Am J Clin Nutr. 1989; 50: 280-287.
 

Inclusion List:

List of Included Articles

 

Barnard ND, Scialli AR, Turner-McGrievy G, Lanou AJ, Glass J. The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity. Am J Med. 2005 Sep; 118(9): 991-997.

Burke LE, Hudson AG, Warziski MT, Styn MA, Music E, Elci OU, Sereika SM. Effects of a vegetarian diet and treatment preference on biochemical and dietary variables in overweight and obese adults: a randomized clinical trial. Am J Clin Nutr. 2007 Sep; 86(3): 588-596.

Burke LE, Styn MA, Steenkiste AR, Music E, Warziski M, Choo J. A randomized clinical trial testing treatment preference and two dietary options in behavioral weight management: preliminary results of the impact of diet at 6 months--PREFER study. Obesity (Silver Spring). 2006 Nov; 14(11): 2007-2017.

Dansinger ML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ.  Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction. JAMA. 2005; 293: 43-53.

Hakala P, Karvetti RL. Weight reduction on lactovegetarian and mixed diets. Changes in weight, nutrient intake, skinfold thicknesses and blood pressure. Eur J Clin Nutr. 1989 Jun; 43(6): 421-430. PMID: 2743965 [PubMed - indexed for MEDLINE] ordered

Kaartinen K, Lammi K, Hypen M, Nenonen M, Hanninen O, Rauma AL. Vegan diet alleviates fibromyalgia symptoms. Scand J Rheumatol. 2000; 29(5): 308-313.

Karlsson J, Hallgren P, Kral J, Lindroos AK, Sjöström L, Sullivan M. Predictors and effects of long-term dieting on mental well-being and weight loss in obese women. Appetite. 1994 Aug; 23(1): 15-26. PMID: 7826054 [PubMed - indexed for MEDLINE] ordered

Mahon AK, Flynn MG, Stewart LK, McFarlin BK, Iglay HB, Mattes RD, Lyle RM, Considine RV, Campbell WW. Protein intake during energy restriction: effects on body composition and markers of metabolic and cardiovascular health in postmenopausal women. J Am Coll Nutr. 2007 Apr; 26(2): 182-189.

Marniemi J, Seppänen A, Hakala P. Long-term effects on lipid metabolism of weight reduction on lactovegetarian and mixed diet. Int J Obes. 1990 Feb; 14(2): 113-125.PMID: 2111292 [PubMed - indexed for MEDLINE] ordered

Turner-McGrievy GM, Barnard ND, Scialli AR. A two-year randomized weight loss trial comparing a vegan diet to a more moderate low-fat diet. Obesity (Silver Spring). 2007 Sep; 15(9): 2276-2281.

Articles Considered, but Excluded

List of Excluded Articles with Reason

 

Article	Reason for Excluding
Campbell WW, Barton ML Jr, Cyr-Campbell D, Davey SL, Beard JL, Parise G, Evans WJ. Effects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men.  Am J Clin Nutr. 1999 Dec; 70(6): 1032-1039.	comparison group<10
Samanta BB. Serum cholesterol in healthy postmenopausal women. Indian J Med Sci. 1998 May; 52(5): 191-195. PMID: 9808910	no intervention

 

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Summary of Articles Identified to Review

Number of Included Primary Research Articles Identified from all sources: 13

Number of Included Review Articles Identified from all sources: 0

Total Number of Included Articles: 13

Number of Articles Considered but Excluded: 2

Total Number of Articles Considered: 13