Vegetarian, Vegan & Raw Vegan Diets: Nutrition, B12 & Expert Advice
A nutritionist has addressed growing public interest in vegetarian, vegan, and crudivegan diets, outlining potential deficiencies and the importance of professional guidance. Pia Obiaño, a licensed nutritionist, discussed the dietary approaches on LU9 Radio Mar del Plata on Thursday, February 19, 2026, focusing on supplementation needs, the risks of ultra-processed foods, and the specific considerations for children and adolescents.
Obiaño explained the historical roots of plant-based diets, tracing them back over 500 years before Christ and their association with the ancient Greek philosopher Pythagoras. She clarified the distinctions between the diets: vegetarianism excludes meat, poultry, and fish; veganism eliminates all animal products, including dairy and eggs; and crudiveganism further restricts food preparation to temperatures below 48 degrees Celsius to preserve nutrients.
A key concern highlighted by Obiaño is the potential for nutritional deficiencies, emphasizing that these diets are not automatically healthy and require careful planning. She specifically identified vitamin B12 as an essential supplement for those following vegan and crudivegan lifestyles. “The body could be using reserves,” she warned, noting that B12 is stored in the liver for up to five years, meaning initial test results may not reflect long-term deficiencies.
Obiaño addressed the challenge of obtaining complete proteins – those containing all nine essential amino acids – without meat consumption. She explained that combining legumes with cereals or nuts can provide a comparable protein profile to meat, while also offering increased fiber, omega-3 fatty acids, and lower cholesterol. She also pointed to the availability of vegan protein powders made from peas, soy, wheat, or corn.
The nutritionist also cautioned about potential digestive issues related to the high fiber content of plant-based diets, noting that some crudivegan patients experience inflammation, flatulence, or digestive disorders. She recommended temporarily incorporating more easily digestible foods like rice, potatoes, or apples during such episodes and considering probiotics to restore gut flora. She stressed the importance of a gradual transition to these diets, guided by professional advice.
Regarding other nutrients, Obiaño discussed the potential for calcium and omega-3 deficiencies due to the exclusion of dairy and fish. She advised evaluating supplementation when necessary and prioritizing organic soy products. She suggested tofu, flax seeds, fruit purees, and aquafaba (the liquid from canned legumes) as egg substitutes.
Obiaño addressed the increasing trend of adolescents adopting vegan or vegetarian diets, suggesting that it is ideally initiated after full skeletal and neurological development. Yet, she acknowledged that ethical convictions often lead younger individuals to explore these options, emphasizing the need for medical supervision and appropriate supplementation in such cases. She also cautioned against dismissing the possibility that dietary changes might mask underlying eating disorders.
Finally, Obiaño refuted the notion that “vegetarian equals healthy,” warning against the consumption of ultra-processed vegan products high in trans fats, sugars, additives, and preservatives. She urged consumers to prioritize foods with fewer than five ingredients and natural components, mirroring the same criteria applicable to any diet. She also addressed common complaints of hunger after eliminating meat, recommending increased legume consumption and strategic cooking techniques to reduce bloating.