Chicago-based registered dietician Christine Fitzgerald likes the diet's plant-based focus. "I do think that we're not eating enough plants, fruits and vegetable and getting the fiber in," she says. "I think for people who like the plant-based way of eating, but feel overwhelmed and can't completely commit to a plant-based diet, this gives them some options."
But she's concerned that the pegan diet limits fruits to low-glycemic berries, claiming that other types of fruit spike blood sugar. "What if you don't like berries? We can do other things to reduce the impact on blood sugar, like pairing fruit with protein," she says.
The diet also emphasises fatty fish and flaxseed - sources of omega-3, another dietary element Delbridge says Americans don't get enough of -- as well as nuts, avocados, olives and associated oils, which provide healthy unsaturated fats. The diet also allows some saturated fat from grass-fed or sustainably raised meat, butter and ghee, along with organic coconut oil and coconut butter.
The mixed bag: Protein, processed food and affordability
The pegan diet considers animal proteins a "condiment" and suggests choosing fish and seafood with lower mercury levels; both recommendations are completely in tune with a healthy "flexitarian" diet. But it also warns to eat beans only "once in a while" and limit them to ½ cup per day, something Delbridge takes issue with.
"Beans are nature's superfood," Delbridge says. "They have protein, they have fiber, they have starch. Beans have been a staple in diets across the world, and beans have shown so many health benefits, including a reduction in cancer risk." He also points out that beans are inexpensive, and that limiting them highlights one of the pegan diet's downsides: "If you are low income, I'm not sure that you can afford to buy the foods that he's suggesting." Indeed, the pegan diet prescribes "organic," "sustainably grown," "pasture-raised," "grass-fed" food. Although this may have environmental and health benefits, and that is still a matter of debate, it can be costly.
The diet limits foods with added sugars to occasional treats and has a long list of "avoids," including pesticides, antibiotics, hormones, genetically modified ingredients, chemicals, additives, preservatives, artificial colors, MSG and artificial sweeteners. Hyman has famously said that the pegan diet can be broken down into one simple rule: "If God made it, eat it; if man made it, leave it."
"To me that's very simplistic, with how complicated our bodies are and what they need nutritionally every day," Delbridge says.
I agree. For one thing, organic farming uses approved pesticides. Furthermore, attempting to completely adhere to that "avoid" list could contribute to orthorexia - an unhealthy obsession with eating healthy - by feeding into the idea that we can disease-proof ourselves if we eat "perfectly." It may also lead to social isolation if a person fears exposure to forbidden foods.
The cons: Going against the grains and dairy
The diet prohibits wheat and other gluten-containing grains, other than occasional intake of the ancient wheat einkorn, falsely claiming that most wheat is genetically modified "Frankenwheat." Although modern wheat does have nutritional downsides, there are countless varieties of heirloom wheat in addition to the ancient wheats einkorn, emmer and spelt.
The pegan diet also limits gluten-free grains like quinoa, brown rice, oats and amaranth. The claim? They raise blood sugar and can trigger autoimmunity. There isn't good science to support the autoimmunity claim for the general population, and any carbohydrate-containing food, including vegetables, can raise blood sugar.
Hyman appears to have softened his stance somewhat on dairy since his 2014 blog post, in which he advised avoiding all dairy because for most people it contributes to a number of chronic diseases, a claim that research does not support. He now allows occasional yogurt, kefir, butter, ghee or cheese, preferably from goat or sheep milk, and always organic and grass-fed.
The bottom line
The pegan diet restricts many nutrient-rich foods, partly because some people can't tolerate them. While it's true that some people are intolerant to lactose or gluten, or have trouble digesting the fiber in beans, that's not the case for most people. Fitzgerald says that if someone follows the pegan diet because they struggle with inflammation or digestive health, it may get in the way of actually discovering the root cause of their health problems.
While Delbridge views the pegan diet as a fad diet, he says it does have one thing going for it besides the abundant produce, omega-3s and low sugar. "The first pro of going on any sort of diet is you are now starting to think about your food. You are prepping in advance. You are controlling your portion size. You're not just running out and grabbing fast food or just shoving anything in your mouth because you're hungry," he says. "To me, we should always be doing that."
Fitzgerald has a slightly different take. "I prefer to not have everyone follow a specific diet, because that puts them in a black-or-white position: They're either following the diet or they're not," she says. "Promoting heart-healthy fats and increasing plant-based eating are such good pros, but understand that you can increase those foods without going down the diet path, so you don't get trapped in the diet mentality."
Dennett is a registered dietician nutritionist and owner of Nutrition by Carrie.
