What are the Benefits and Cautions with a Vegan Keto Diet?

Benefits and Cautions with a Vegan Keto Diet

The vegan’s version of the popular ketogenic (or keto) diet is very similar to a standard keto diet in terms of macro proportions, so the benefits are similar, with a few VERY IMPORTANT added ones. The ketogenic diet, (which is where you aim to take in low quatities of carbs, high quantities of fat, and moderate amounts of protein)  was first used in an attempt to deal with epilepsy in children, with some degree of success. The truth is that very few studies have actually looked at the long-term effects of ketogenic diets, so most of the “facts” you will find are anecdotal, rather than research-based. In many ways, the standard ketogenic diet is just a variation of the previous Dr. Atkins’ Diet. Therefore, it suffers from most of the same pitfalls.

Problems with Standard Keto Diet

To understand the benefits of the vegan keto diet, we first need to understand the problems with the standard ketogenic diet. The standard ketogenic diet emphasizes fats as the main calorie (body fuel) source. That means that fried foods, cheese, and meat tend to be featured items on the menu. Fruits are very limited to only some berries, starchy vegetables like carrots, beets, and potatoes are pretty much eliminated, and grains and legumes are mostly eliminated because of their higher carbohydrate content. Nuts, seeds, avocados, and some oils are eaten in fairly large quantities. Protein is almost always from animal sources, in the form of meat. When most of your calories are from the fat and protein in your diet, you can see that animal products would take up the lion’s share of the plate.

Harvard Study

Harvard University did a study on 100,000 people to study the effects of the low-carb, high-fat diet on health, which was reported in the Annals of Internal Medicine (see References). This study followed people over 26 years and the researchers were interested in how this diet affected mortality, or risk of dying. What they found was stunning — on the low-carb, high-fat diet people had a significantly higher risk of dying at a younger age, suffering from cardiovascular disease and heart attacks, and developing cancer. Often their blood lipids were also out of whack with higher levels of LDLs and cholesterol. So although the participants may have lost weight, the only way that actually helped them may have been that they required a skinnier coffin!

Some researchers  wondered whether the increased risk of dying was connected to the low carb/high-fat diet, or whether it was because of all the animal products these people were consuming. So they designed a study that still had high fat and protein levels, was low-carb, but involved no animal products. Basically they had a vegan version of the Atkins/ketogenic diet. They called this the “eco-Atkins diet”. So how did they do it? Well,  lots of plant protein foods like tofu, seitan, wheat gluten, tempeh, vegetarian versions of cold cuts, bacon, sausages, lots of nuts, and avocado were involved! As reported in the Archives of Internal Medicine, in just two weeks, the research subjects’ LDL (bad blood fat) levels dropped by 20 percent. In the other study, most people’s cholesterol levels went up. They only ran the study for four weeks, so it’s difficult to make any longer-term generalizations.  But the Harvard researchers thought it was interesting enough that they went back to their big study of 100,000 people and picked out those that were on a plant-based low-carb diet. That’s one of the advantages of having such a large study group — you can find people that are eating almost anything!

Impact on Mortality (Dying!)

Here is where it got really interesting: if you can imagine a straight horizontal line that represents people on a regular American diet, that would also be the mortality rate. When you look at people on a Atkins-style diet, the line representing their mortality rate zooms up and away from the the regular diet, demonstrating their significantly higher risk of dying from all causes, compared to the regular diet. But what do you suppose they found with those on the plant-based low-carb diet? No, the risk was not just reduced from the Atkins-style group, or even equal to those on the regular diet. Instead, their risk of dying from all causes was significantly LOWER than those even on a regular diet. What this shows us is that it makes a BIG difference whether your fat and protein come from animal sources or if it is plant-based, even if you are doing a low-carb diet.

Given all the other studies we have that show the harm to health caused by animal fats and proteins, I could never recommend that anyone follow a standard ketogenic diet, even if they were losing weight, feeling great, controlling their diabetes, and thought it was great. I do believe that some people who have struggled to lose weight in other ways and feel this is the only way they can do it, should stick to a strict plant-based version. Even so, because it is so restrictive, there is no way to get all the micronutrients we need for overall health just from this limited list of foods. For this reason, I don’t think it is the best choice to eat vegan keto for a long period of time. It can dovetail nicely into intermittent fasting regimes or mimicking fasting on keto-inducing days.

Safe Vegan Keto

So if you choose to do a vegan keto diet, to get the most benefit from it, make sure you are supplementing adequately to try and make up for the highly restrictive allowed foods list. Work with your health care provider to get a baseline assessment and make sure all your dietary needs are addressed. Some of supplements that might be recommended are a multivitamin to make sure you are getting enough B12, D, zinc and other trace minerals, and iron.


In any case, you might want to consider alternating between vegan keto and a straight plant-based diet. If you are trying to lose weight, many people will find that a lower carb vegan diet will do the trick. The reason many people struggle to lose weight even when vegan is that they tend to be consuming higher levels of carbs, including refined ones. But doing the vegan keto diet for a few weeks is a great way to get used to more of your vegan low-carb food options. Then you can increase your carbs a bit, but stay on the low-carb side of things for continued weight loss and health benefits. If you find that you gain weight steadily when coming off a keto diet in spite of exercising regularly, you might want to work with your integrative health practitioner to check and balance hormone levels. Often impaired liver function and high insulin levels are at fault for that phenomenon, but without laboratory testing, it’s impossible to determine the cause.

To learn what you can eat on a vegan keto diet, check out this article What is a Vegan Keto Diet and How do you Implement a Vegan Keto Diet.



Ann Intern Med 2010;153:289-298

Arch Intern Med 2009; 169(11):1046-1054

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