Vegetarian Diets
Many people choose to follow some form of a vegetarian diet, often saying that it’s healthier. But is there compelling evidence that this is the case?
Article By: The Weight Watchers Research Department
Types of vegetarian diets
There are several types of vegetarian diets. A lacto-ovo vegetarian diet excludes meat, poultry and fish but includes eggs and dairy. A lacto-vegetarian diet leaves out eggs and an ovo-vegetarian diet eliminates dairy but includes eggs. A vegan diet, a highly restrictive form of vegetarianism, excludes all animal-based products, including meat, poultry, fish, eggs, dairy, and honey.
Nutritional risks of vegetarians diets
Vegetarian diets can meet all nutritional requirements, but a few nutrients require special attention to ensure that they are taken in adequate amounts. Specifically, nutrients at risk of being under-consumed include protein, n-3 fatty acids, iron, zinc, iodine, calcium, and vitamins D and B-12.
1 By choosing plant-based foods that are rich in these nutrients, a nutritionally complete diet can be achieved.
Are vegetarians healthier than non-vegetarians?
While many assume that vegetarians are healthier than non-vegetarians, the scientific evidence is not consistent. There are some studies that show health benefits from following a vegetarian diet. For example, a study looking at 34,192 California Seventh-Day Adventists suggested that the vegetarians had lower risks of hypertension, arthritis and diabetes mellitus than the non-vegetarians.
2 Other research done in the United Kingdom found lower blood pressure among non-meat eaters.
3 It is important to note, however, that lifestyle habits beyond eating may account, at least in part, for the findings. For instance, Seventh-Day Adventists practice an overall “healthier” lifestyle, such as not smoking and not drinking alcohol, in addition to abstaining from meat. Other potential cardio-protective dietary factors in a vegetarian diet include soy protein, fruits and vegetables, whole grains, nuts, and phytochemicals, which also may help lower risk of diabetes.
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In its position paper on vegetarian diets, the American Dietetic Association (now the Academy of Nutrition and Dietetics) also notes that vegetarians have a lower overall rate of cancer and no difference in bone health when lacto-ovo vegetarians are compared to non-vegetarians.
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Among the Seventh-Day Adventists, vegetarians also had a lower BMI than non-vegetarians.
2 Participants in the EPIC-Oxford Study who cut back on animal-based foods showed the lowest rate of weight gain.
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Bottom line: The overall nutritional contribution of a diet is not determined by merely excluding or including types of food. Rather, the quality is the sum of the food choices that are made. Both vegetarian (in its many forms) and non-vegetarian diets can be of a high or poor nutritional quality, and it is the quality of the diet that ultimately affects health.
Weight Watchers Approach
Because of the flexibility built into the PointsPlus system, a person choosing to follow any form of vegetarianism can participate. To ensure nutritional adequacy, additional information for vegetarians is provided.
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view footnotes
1 Position of the American Dietetic Association: Vegetarian diets. Am Diet Assoc. 2009 Jul;109(7):1266-1282
2 Fraser GE.
Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999 Sep;70(3 Suppl):532S-538S.
3 Appleby PN, Davey GK, Key TJ. Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC-Oxford.
Public Health Nutr. 2002;5:645-654.
4 Rosell M, Appleby P, Spencer E, Key T. Weight gain over 5 years in 21,966 meat-eating, fish-eating, vegetarian, and vegan men and women in EPIC-Oxford. Int J Obesity. 2006;30:1389-1396.