Plant-based eating has moved firmly into the mainstream. Whether motivated by ethics, health, or environmental sustainability, more people are choosing vegetarian or vegan diets. Dietitians help ensure these choices remain nutritionally complete, practical, and enjoyable1.
Defining Plant-Based Patterns
- Lacto-ovo vegetarian: Excludes meat, poultry, and fish but includes dairy and eggs.
- Lacto-vegetarian: Includes dairy but avoids eggs, meat, poultry, and fish.
- Vegan: Excludes all animal products, including dairy, eggs, honey, and gelatin.
- Flexitarian: Primarily plant-based with occasional animal foods for flexibility.
Each variation can meet nutrient needs if planned with variety and fortified foods in mind2.
Health Benefits Supported by Research
Large cohort studies consistently show that balanced vegetarian and vegan diets are linked with lower risks of ischemic heart disease, hypertension, type 2 diabetes, and some cancers3. They are typically lower in saturated fat and higher in fiber, antioxidants, and phytochemicals. However, these benefits depend on food quality—an ultra-processed vegan diet can still be nutrient-poor and high in refined carbohydrates4.
Key Nutrients to Monitor
| Nutrient | Potential Concern | Reliable Sources / Strategies |
|---|---|---|
| Protein | Quality and variety | Beans, lentils, soy, nuts, seeds, quinoa, seitan; combine different plant proteins through the day5 |
| Vitamin B12 | Absent in plants | Fortified plant milks, nutritional yeast, or supplements (25–100 µg daily or 1,000 µg weekly)6 |
| Iron | Lower absorption (non-heme) | Legumes, tofu, spinach, fortified cereals, pumpkin seeds; pair with vitamin C foods7 |
| Calcium | Low dairy intake | Fortified milks, tofu with calcium sulfate, leafy greens like bok choy and kale8 |
| Vitamin D | Limited in food supply | Sunlight exposure, fortified beverages, or D2/D3 supplements (D3 from lichen for vegans)8 |
| Omega-3 fatty acids | No marine source | Chia, flax, walnuts, hemp seeds; consider algae-based DHA/EPA supplement9 |
| Zinc & Iodine | May be low in strict vegan diets | Whole grains, nuts, iodized salt, seaweed (monitor iodine content carefully)10 |
Practical Meal Planning Tips
- Base meals around whole grains, legumes, and vegetables to ensure adequate calories and nutrients.
- Include a source of plant protein at each meal (tofu, tempeh, lentils, beans, or nuts).
- Incorporate colorful produce for antioxidants and diverse micronutrients.
- Use fortified milks and spreads for calcium, B12, and vitamin D.
- Plan snacks with protein and fiber—trail mix, hummus with vegetables, or soy yogurt.
Children, Pregnancy, and Older Adults
Vegetarian and vegan diets are safe for all life stages when appropriately planned, according to the Academy of Nutrition and Dietetics1. Infants and children require energy-dense meals and fortified foods to support rapid growth. During pregnancy, additional iron, DHA, and B12 may be needed. For older adults, attention to protein distribution, B12 absorption, and vitamin D synthesis is key8.
Environmental & Ethical Dimensions
Plant-based diets generally have lower greenhouse gas emissions and resource use than omnivorous diets. Still, sustainability depends on sourcing—imported processed foods can offset these gains. Local, seasonal produce and minimal waste amplify both environmental and community benefits11.
Frequently Asked Questions
Can I get enough protein without meat?
Yes. Combining varied plant proteins (grains, legumes, soy, nuts) across the day easily meets amino acid needs5.
Do I need supplements on a vegan diet?
Vitamin B12 is essential, and most people also benefit from vitamin D and DHA/EPA supplements, especially with limited sun exposure or fish intake6, 9.
Is soy safe?
Yes. Numerous studies show that moderate soy intake supports heart health and may reduce breast and prostate cancer risk12.
References
- Academy of Nutrition and Dietetics. Position on Vegetarian Diets. J Acad Nutr Diet. 2016.
- British Dietetic Association. Plant-Based Nutrition Guidelines. bda.uk.com
- Orlich MJ, et al. Vegetarian dietary patterns and mortality. JAMA Intern Med. 2013.
- Satija A, Hu FB. Plant-based diets and cardiovascular health. Trends Cardiovasc Med. 2018.
- Messina M. Plant proteins in human nutrition. Nutrients. 2019.
- Pawlak R. Vitamin B12 in vegan diets: a review. Nutrients. 2013.
- Hunt JR. Bioavailability of iron and strategies to improve absorption. Am J Clin Nutr. 2003.
- National Institutes of Health, Office of Dietary Supplements. Vitamin D and calcium fact sheets. ods.od.nih.gov
- Derbyshire E. Plant sources of omega-3 fatty acids and implications for human health. Nutrients. 2017.
- Craig WJ. Health effects of vegan diets. Am J Clin Nutr. 2009.
- Clark MA, et al. Multiple health and environmental impacts of foods. Proc Natl Acad Sci USA. 2019.
- Messina M, et al. Soy and health update: evaluation of the clinical and epidemiologic data. Nutrients. 2022.