The American Dietetic Association (ADA) classifies lacto-ovo-vegetarians as consuming plants and animal products (e.g., dairy products, egg) while excluding meat and fish. This diet meets the Dietary Guidelines for Americans and also the Recommended Daily Allowance for nutrients. This diet is associated with many health benefits compared to other diets such as vegan.

A Harvard Health Publication shows research results that lacto-ovo-vegetarians get the recommended amount of protein per pound of body weight. The American Dietetic Association suggests consuming a variety of food rich proteins (e.g., dairy products, eggs) daily to help achieve the appropriate protein levels.

A Heidelberg Study published in 2005 shows that vegans are linked to a higher mortality rate compared to lacto-ovo-vegetarians. Michael J Orlich of Loma Linda University conducted a study with 77,659 participants and concluded that lacto-ovo-vegetarians have an 18 percent lower chance of developing colorectal cancer compared to vegans, pescovegetarians (vegetarians who include fish in their diet), and semi-vegetarians (those that ate meat once a week).

These next three studies compared lacto-ovo-vegetarians to vegans and semi-vegetarians.

• Lacto-ovo-vegetarians have a 38% and 34% lower chance of dying from lung cancer and heart disease respectively, compared to vegans and semi-vegetarians (Health Food Shoppers Study).
• Lacto-ovo-vegetarians had a lower risk of developing cataracts than the meat eaters while vegans had the lowest risk (EPIC-Oxford study).
• Lacto-ovo vegetarians consume as much calcium as meat eaters (Harvard Health Publication). The study also revealed that 75% of vegans consume less calcium than the recommended level. The body needs 525 mg of calcium on a daily basis. Otherwise, the body can be exposed to fracture and risks of osteoporosis.

A complete vegan diet has immense health benefits and is reported to have a 19 percent lower risk of cardiovascular diseases and lacto-ovo-vegetarians have an 18 percent lower risk, compared to a diet that includes meat. However, a vegan diet has lower protein, omega 3 fatty acids, calcium, and vitamin B12, compared to the lacto-ovo-vegetarian diet.

Deficiencies of essential nutrients like vitamin B12 and calcium can result in health disorders like poor bone development. There is also a risk of cancer and neurological disorders due to decreased vitamin B12 intake.

Vitamin B12 concerns can be rectified by consuming a lacto-ovo vegetarian diet. It is reported that the risk of cancer is reduced by 22 percent in lacto-ovo-vegetarians. With lower risks of developing cardiovascular diseases, lung cancer, cataract, osteoporosis, etc., and avoiding deficiencies in animal protein and vitamins, the lacto-ovo-vegetarianism would appear to be a better choice than a vegan diet for those individuals who want to avoid meat consumption.

References:

(2009 Oct 1). Becoming a Vegetarian. Retrieved from  http://www.health.harvard.edu/staying-healthy/becoming-a-vegetarian  

Eat a Variety of Foods. Retrieved from http://www.health.gov/dietaryguidelines/dga95/variety.htm

Chang-Claude, J., Hermann, S., Eilber, U., & Steindorf, K. (2005). Lifestyle determinants and mortality in German vegetarians and health-conscious persons: results of a 21-year follow-up. Cancer Epidemiol Biomarkers Prev, 14(4), pp. 963-8. Retreived from http://www.ncbi.nlm.nih.gov/pubmed/15824171

Michael J. Orlich, Pramil N. Singh, Joan Sabaté, Jing Fan, Lars Sveen, Hannelore Bennett, Synnove F. Knutsen, W. Lawrence Beeson, Karen Jaceldo-Siegl, Terry L. Butler, R. Patti Herring, Gary E. Fraser. (2015). Vegetarian Dietary Patterns and the Risk of Colorectal Cancers. JAMA Internal Medicine, DOI: 10.1001/jamainternmed.2015.59

Norris, J. (2013 Dec). Disease Rates of Vegetarians and Vegans.  Retrieved from http://www.veganhealth.org/articles/dxrates

Appleby, P.N., Allen, N.E., & Key, T.J. (2011). Diet, vegetarianism, and cataract risk. Am J Clin Nutr, 93(5), pp. 1128-35. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/21430115

Grant, R. (2010 Apr). A Lacto-ovo Vegetarian Diet vs a Vegan One. Retrieved from http://www-signsofthetimes-org-au.adventistconnect.org/items/a-lacto-ovo-vegetarian-diet-versus-a-vegan-one