By Rachel Wyman
Clinical Nutrition Educator
Vegan. Vegetarian. Meat-free. Plant-based.
No matter what you call it, there are many things to take into consideration when deciding whether you should change your diet to eliminate meat and other animal byproducts. Here, we take look at how a plant-based diet impacts your health and wellness.
What the research says
Observational research positively associates vegan diet followers with a lower body mass index (BMI) and less weight gain with aging.
Noteworthy among interventional research, a study just this year examined the effectiveness of a whole food plant-based diet program. Half of the participants followed a low-fat vegan diet without calorie restriction and attended classes twice per week for twelve weeks, while the other half of participants did neither. The low-fat vegan diet group lost an average of 27 pounds and 4.4 BMI points in six months, while the other participants had no significant reduction in BMI.
Elsewhere, a 2015 meta-analysis pooled results from 1,151 participants from 12 randomized controlled trials. Individuals assigned to vegetarian diets lost an average of 4.5 pounds more in a span of 4.5 months compared with those following nonvegetarian diets.
In regards to weight management, whole plant foods contain fiber, resistant starch and water, adding volume to meals while lowering calorie density. Dietary fiber can also slow gastric emptying, contributing to a longer sense of fullness after meals. Also, a plant-based diet may limit one’s variety of options when eating out, leading to more home-cooked meals, which are typically lower in calories, fat, sodium and sugar than restaurant meals.
Plant-based diets offer other personal health and environmental health benefits. Whole plant foods are rich in disease protective antioxidants and phytochemicals. Vegetarian diets are associated with better serum lipid profile, lower blood pressure, and less arterial plaque. Plant-based diets are also linked to lower all-cause mortality and lower incidence of cancer, particularly digestive cancers such as colon cancer. Plant-based diets are more environmentally sustainable, using less water, fossil fuels, pesticides, fertilizers and antibiotics, and producing 2.5 times less greenhouse gas.
Things to consider
As with all eating patterns, weight loss on a plant-based diet is not guaranteed. Vegan diet pitfalls to avoid include heavily processed foods that have a “health halo,” high-calorie juices, smoothies and sweetened plant milks, and excessive portions of plant oils and fats. Also, to help increase fullness without overeating, it is helpful to minimize refined starches and sugars in favor of whole grains and legumes, which are richer in fiber and protein.
When shifting to a plant-based diet, thoughtful consideration must be taken to include sufficient nutrients typically less consumed than in nonvegetarian diets. These include: omega-3 fatty acids, iodine, calcium, vitamin D, iron and vitamin B12. Pregnant and lactating women, infants and children, and older adults may especially benefit from the expertise of a registered dietitian to help create a well-designed eating pattern that meets all nutrient needs.
Rachel Wyman, RD, is Clinical Nutrition Educator at Mission Weight Management.