Is there such a thing as the one and only healthy way to eat? Best-selling authors like Dr. Mark Hyman would like you to think so.

Recently, he’s become a proponent of an eating style that he calls “pegan,” which as you might guess is a portmanteau of Paleo and vegan. In designing this diet, Dr. Hyman says that he “synthesized the best aspects of each and integrated them with the anti-inflammatory and detoxification principles of functional medicine to create a balanced, inclusive dietary plan that changed my life and my patients’ lives, too.”

Uh oh –“detoxification principles” plus anecdotal evidence pretty much raises red flags all over the place for me.

But Dr. Hyman is correct in saying that his diet is a more accurate and healthful approach to a Paleo pattern, which has been used as an excuse to eat too much meat and too few plant foods.  And, from a health standpoint, his diet isn’t exactly awful. He allows up to 2 ½ cups of grains, beans and starchy vegetables combined plus 2 servings of fruit. Non-starchy vegetables are unlimited and he encourages nuts, seeds and healthy fats. Based on the simple fact that refined carbs are off limits on this eating plan, and that lots of veggies are encouraged, it’s automatically a vast improvement over the way most people in the United States eat. But is it the best way to eat? Is it better than eating a vegan diet? I doubt it. And I certainly wasn’t convinced by Dr. Hyman’s rationale for moving away from veganism. Here’s what he says:

But even a perfect vegan diet won’t provide enough DHA and EPA, which are important omega-3 fatty acids. Neither will it provide enough iron, zinc, copper, or vitamin D. Vegans are also unlikely to be getting the amount of quality proteins and essential amino acids they require, especially as they age. It’s possible to find sufficient amounts in non-animal sources, but it is incredibly challenging. But they’re definitely not getting B12 because it only comes from animal foods. Finally, it’s entirely possible to be a vegan and still eat a poor diet filled with sugar, refined grains and flour, highly processed oils, soy-based protein substitutes, and foods loaded with chemicals and additives. You can live on Oreos, potato chips, and root beer and still call yourself a strict vegan.

Okay, there’s a lot to unpack here.

First, the whole concept of “enough DHA and EPA” is problematic. These are not essential nutrients and there is no RDA for these fats. But, for those who want to include them in their diet (like me) vegan supplements provide the exact same DHA and EPA you would get from fish. I know that some people think supplements are an inferior choice, and I don’t understand that. If you can get the exact same fatty acids in a way that is sustainable and that doesn’t contribute to the cruelty that is an inherent part of the fishing industry, wouldn’t that seem to be the better option?

Likewise, the fact that vegans need to supplement with vitamin B12 may seem annoying, but since it’s so easy to do so, it’s hardly a reason to abandon a vegan diet. Not to mention the fact that for older people (again, like me, and also, by the way, like Dr. Hyman) supplements are a better source of vitamin B12 than animal foods.

Other nutrients, like iron and zinc, require some attention in vegan diets, but acknowledging this is different from saying that you can’t get enough of these nutrients from plant foods. And getting adequate protein from plant foods is not “incredibly challenging.” It’s incredibly easy.

Finally, while it’s true that you can be a vegan who eats junk food, this is irrelevant to any argument against veganism. If you are a vegan who eats too many Oreos, the solution is not to start eating fish and grass-fed beef. It’s to eat fewer Oreos.

I suspect that one of the reasons Dr. Hyman worries about protein on a vegan diet is that he believes you should restrict beans because they may cause spikes in blood sugar. He recommends limiting beans overall and choosing lentils over “big starchy beans.” This is wrong. Chickpeas have a lower glycemic index than lentils, and black beans are about equal to lentils when it comes to raising blood sugar. In addition, beans in general are packed with protein, fiber and resistant starch, which makes them a good choice for people who need to manage blood glucose levels.

It’s not just beans that Dr. Hyman worries about, though. The pegan diet comes with a long list of restrictions including gluten, GMOs, and soybean oil. He recommends limiting certain fruits like melons. He advises staying away from “chemicals,” whatever that means.

Furthermore, a pegan diet incorporates very particular guidelines around the foods you are allowed to eat. Not only are you supposed to fill half your plate with fruits and vegetables, but they should all be organic. If you eat wheat at all (and apparently you really shouldn’t) you should stick with heirloom varieties. If you consume dairy, it should be organic, grass-fed and preferably from sheep or goats. A healthy pegan diet is supposed to include foods like wild-caught salmon, grass-fed beef, and cold-pressed oils. Clearly, a pegan diet is not for those who are on a budget.

In short, a pegan diet is likely to be an improvement over the way many people eat and it’s certainly better than the popular Paleolithic diet. But it’s not an improvement over veganism. It’s just the opposite in fact. It will make your diet less compassionate without making it any healthier.