There are three sources vegans tend to cite to prove that veganism is a healthy diet: The American Dietetic Association (which they often refer to as “the conservative ADA” to boost its credibility), The China Study and the Adventist Health Studies. However, “the conservative ADA” seems to be the vegan favorite:

Gary Francione: Most people eat animal flesh and animal products. No one maintains that we need to eat these products for optimal health; on the contrary; mainstream medical people are, with increasing frequency, arguing that animal products are detrimental to human health. But whether or not animal foods are detrimental, they certainly are not necessary. Even the conservative American Dietetic Association acknowledges this:…

Ryan M: Women can be perfectly healthy on a vegan diet throughout pregnancy and during nursing, as even the conservative ADA has said. Thanks for sharing your story, but you can hang onto the advice.

Vegan Street: By the way, the conservative ADA has acknowledged for years that it is possible to be healthy on a plant-based diet.

NYCVeg: To be honest, I’m a little concerned that your midwife seems so ignorant about vegetarian diets. Even the notoriously conservative ADA says that vegetarian (and vegan) diets are healthy for all stages of life, including pregnancy.

Kathy Freston: Even the very conservative ADA (American Dietetic Association) says:

Vegetarian diets are often associated with a number of health advantages, including lower blood cholesterol levels, lower risk of heart disease, lower blood pressure levels, and lower risk of hypertension and type 2 diabetes. Vegetarians tend to have a lower body mass index (BMI) .. and lower overall cancer rates.

Spartacus: Even the pretty conservative ADA (American Dietetic Association) has the following to say about this:

It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.

Alan Benedict: Readers interested in an objective assessment of the facts by an authoritative source need only review the well documented position of the nutritionally conservative American Dietetic Association…

Alex: Your argument has been refuted by the conservative American Dietetic Association (ADA), arguing, as it does, that veganism is healthy at all stages of the life cycle.

Virginia Messina [co-author of the 1997 and 2003 ADA position papers on a vegetarian diet, as well as a reviewer for the 1993 and 2009 vegetarian position papers]: It’s a safe bet that Angelina didn’t understand healthful vegan eating, though. After all, even the conservative American Dietetic Association says that a vegan diet is safe and healthful.

It’s true that the American Dietetic Association has published positive position papers on vegetarianism since 1988, shortly after the formation of the Vegetarian Nutrition Dietetic Practice Group, which has been in charge of the ADA’s vegetarian position papers since that time. Yet despite the cohesive image the ADA likes to present of its members, there seems to be a slight schism between what the Vegetarian Nutrition Dietetic Practice Group members (most of whom are vegetarians or vegans themselves) think of a vegan diet, and what the other “conservative” ADA members think.

Here are a few quotes from non-vegan ADA spokespeople who seem less enthusiastic about veganism than they are supposed to be:

Keri Gans

(NY Daily News):

"You can meet a child’s nutritional needs with a vegan diet, but it is very difficult," says Keri Gans, RD, MS, CDN, spokeswoman for the American Dietetic Association. "When you take away dairy food, you have to worry about how the child will get calcium and vitamin D."

And while it’s possible to ensure that a child gets these nutrients from other sources, it’s hard - unless your kid absolutely loves vegetables. To get the calcium in one cup of milk, a child would need to consume four cups of broccoli, Gans points out.

Another risk with a vegan diet is that a child may not get enough protein - or at least the complete protein that is offered by meat and dairy products.

Non-meat protein sources don’t necessarily have all the amino acids, pediatric dietitian Helen Wilcock, a member of the British Dietetic Association, told The Guardian.

"If a child eats meat or fish, it’s easy to get all the right amino acids," she says. "But if a child is getting protein from pulses [beans], the problem is that one type of bean might not provide every amino acid, so there has to be a good balance of pulses." A kid who eats meat gets all the amino acids, she notes, but a kid who consumes just one type of bean will not.

Other nutritional deficiencies that can crop up with a vegan diet include not getting enough iron or omega 3s, Gans points out. Those omega 3s are essential for cardiovascular health as well as brain development, she says.

While a vegan diet can work for an adult, a child’s growing body requires many nutrients if he or she is to thrive, Gans says. “If the family knows what they are doing, works with a professional and gets the proper supplements, the needs could be met,” she says.

In general, kids on vegan diets tend to be a little smaller than other kids. Part of the problem with feeding them stems from the fact that a lot of the foods they eat just are not that calorie-dense, so they need to eat a lot in order to get enough calories.

A PR rep from The American Dietetic Association disowned Gans’ statements here, saying they were taken out of context. I emailed the reporter of this article to see if she had a transcript of their conversation, but she didn’t respond. Judging from other Keri Gans quotes and paraphrases in the media, though, the above seems close enough to her true views:

(ABC News):

But as American Dietetic Association spokeswoman Keri Gans noted, vegetarianism must be done right to reap the benefits. … Specifically, vegetarians must find sources other than meat for protein. Those who opt to go vegan must be even more vigilant when it comes to finding substitutes for other nutrients, such as the calcium that they might otherwise get from dairy products.

(USA Today):

"A lot of individuals are interested in trying [veganism]," says Keri Gans, a registered dietitian in New York City and spokeswoman for the American Dietetic Association (ADA). "Unfortunately, they don’t all do the necessary research that can make it a healthy choice."

Gans says some under-informed newbie vegans end up just plain hungry, attempting to subsist on salads and soy milk. Others “end up gaining weight because they eat too many carbohydrates from pasta and rice or too many fatty nuts and seeds,” says Tara Gidus, a registered dietitian in Orlando, who also is an ADA spokeswoman.

Dawn Jackson Blatner

(CBS News):

"A vegan lifestyle can be healthy, but it takes more planning than most other types of diets to ensure no deficiencies, especially of protein, iron, zinc, calcium, Vitamin-D, B12 and omega-three fatty acids," said Blatner, who is also a spokeswoman for the American Dietetic Association.

(The Seattle Times):

Dawn Jackson Blatner, a spokeswoman for the American Dietetic Association, approves of the vegan-before-6 idea. But like full-time vegans and vegetarians, part-timers need to be aware of getting enough of certain nutrients, she says. Among these are Vitamin B12 (found mostly in meats), protein, iron and zinc (all of which are in beans), calcium and vitamin D (mostly in dairy products, and in fortified soy and almond milks), and omega-3 fats (in fish, flax seed and walnuts).

Blatner also cautions that while Bittman lost weight through his new way of eating, it’s easy for vegans and vegetarians to consume too many calories. “You can do it wrong,” she says. “You could overeat olive oil, nuts and seeds, or over-portion peanut butter, so you’d eat too many calories.”

(WebMD):

Blatner thinks [vegan] dieters would benefit from having nutrition information and a nutrient analysis of recipes and meals, because vegetarian diets can be lacking in protein, iron, zinc, calcium, vitamin D, riboflavin, vitamin B12, omega 3 fatty acids, and iodine.

Dave Grotto

(Park City Daily News):

"With tenacity and proper planning, a vegan diet can meet the needs of 10-year-olds," said registered dietitian Dave Grotto, a spokesman for the American Dietetic Association. … The most common potential problems for vegetarians include a reduced intake of iron, calcium and vitamin B-12. Grotto, who advocates plant-based foods but doesn’t believe vegan diets are optimal for children because they require constant monitoring, recommends taking a multivitamin that contains iron and zinc as a safety net. But even this is tricky because certain compounds can decrease iron and zinc absorption.

Jackie Newgent

(The Day):

"This is particularly a problem among teen vegetarians," says dietitian Jackie Newgent, a New York spokeswoman for the American Dietetic Association, because teenagers require more calcium and iron than adults do.

"It’s possible to still get these nutrients from vegetarian sources-you can drink calcium fortified orange juice and include legumes, dark, leafy greens and iron-fortiried cereals and breads in your diet. But you need to plan your diet properly in order to get these essential vitamins and minerals."

Shareen Marshall

(St. Paul Business Journal):

Shareen Marshall, a dietitian at St. Louis Park-based Park Nicollet Health Services [and a member of the American Dietetic Association], said vegetarian diets may be healthy. But the diets, especially vegan diets, can also be difficult, with a great deal of attention needed to prevent lack of protein, calcium, vitamin D, iron and vitamin B-12.

"You could be at risk for not having all your nutrients," Marshall said.

Lona Sandon

(Dallas Morning News):

Lona Sandon, a registered dietitian at UT Southwestern Medical Center and a spokeswoman for the American Dietetic Association, confirmed that plant-based diets, including Mediterranean and vegetarian ones, can provide health benefits.

She cautioned that strict vegan diets often come up short on vitamin D, calcium, zinc, iron and protein, in addition to B vitamins. A vegan diet typically is much higher in fiber than people are accustomed to, which can interfere with iron absorption and can initially cause gastrointestinal distress, she said.

"It can be a healthy diet in terms of fighting heart disease," Sandon says. "But it comes with its own pitfalls with vitamin and mineral deficiencies that people need to be careful about. You don’t have to go to extremes to have a healthy heart."