For something as basic as eating, there sure is a lot of confusion over how to best do it. For centuries, humans ate what they found or could grow — it was simple. For the past few decades, though, we have created “diets,” or prescribed eating plans that purport to provide the best possible nutrition, weight control and longevity. How does one choose?
It sometimes seems like an NCAA basketball bracket, pitting one eating plan against another. So for those of you keeping score at home, here is today’s contest: the keto diet vs. a plant-based diet.
Keto Diet Overview
The ketogenic, or keto, diet is a high-fat, low-carbohydrate eating plan. When following the keto diet, you are told to severely reduce carbohydrate consumption to less than 50 grams per day — for perspective, the recommended daily intake is in the 200- to 300-gram range — and replace the majority of those calories with fat.
It is the opposite of what many nutrition experts have told us in the past; namely, to control fat, which is linked to a variety of health issues including diabetes, heart disease, dementia and early death.
The keto diet is intended to induce a biological condition called ketosis. This occurs when the body, starved of glucose-producing fat, is forced to turn stored fat into ketones for energy.
A very precise, strict version of this diet plan is sometimes prescribed by physicians to help manage some severe cases of epilepsy, a disorder involving seizures. These patients are very carefully monitored by their doctors, as this is a medical treatment that can help reduce the strength and frequency of seizures.
Plant-Based Diet Overview
“The plant-based diet is a somewhat vague term regarding eating plans that minimize animal products,” says Megan Wroe, dietitian and wellness manager at St. Jude Medical Center in Fullerton, California. “There is no definite definition, however, and the term ‘plant-based’ is used by some to mean vegetarian, for others to mean vegan and by others to mean a flexitarian diet including mostly plant foods,” and also some animal products.
The common thread here is that plants — fruits, vegetables, beans, legumes, whole grains, plant-based oils like olive oil and anything else that grows in the ground — comprise most or all of your plate.
What’s the Difference?
The obvious difference is in the nutrients each eating plan is focused on. “The approach to macronutrient amounts and food sources is where you will see major differences between the two diets,” says Kristen Smith, a registered dietitian and the bariatric surgery coordinator for Piedmont Healthcare in Atlanta. “The keto diet focuses on macronutrient breakdown, prioritizing animal-based protein sources and minimizing carbohydrate amounts, while a plant-based diet focuses less on protein and more on the source of the food. A plant-based diet doesn’t limit a macronutrient group — carbohydrates — and tends to be significantly higher in carbohydrate amounts.”
“These are very different methods of looking at diet. These diets have very different goals and cannot really be compared fairly,” Wroe stresses.
Following a keto diet, at least for a short period of time, can help some people lose weight and control blood sugar. And, as mentioned above, it may be very useful for someone with hard-to-manage epilepsy.
Plant-based diets are considered a far healthier way to eat; in fact, most nutritionists will tell you it’s the single best plan to follow for overall health, weight control and longevity. “Plant-based diets can provide adequate nutrition and may offer health benefits in the prevention and treatment of certain diseases,” says Smith, the author of a healthful eating blog, 360 Family Nutrition, and a spokesperson for the Academy of Nutrition and Dietetics.
Wroe agrees: “Plant-based diets are recommended for everyone.”
[See: The Best Plant-Based Diets.]
The Risks and Challenges
The keto diet carries many risks and potential problems.
For one, many people complain of flu-like symptoms when first starting the diet. “Some people refer to this as the keto flu,” Wroe says. And the restrictiveness of the diet makes it very difficult to maintain for more than a short period.
Because the keto diet involves restricting an entire food group, it’s important to ensure you are getting those nutrients in other forms. “The high-fat intake of the keto diet is controversial among health care professionals. Long-term cardiovascular health effects are not known,” Wroe says. Anyone following a keto diet should consult with a physician about the risk of gallbladder conditions. The high fat in this diet can lead to gallstones or even the need for gallbladder removal for some followers, she says.
When starting a plant-based diet, it “may be challenging to ensure adequate nutritional intake,” Smith says. “A common challenge is adequate protein intake and knowing what plant-based foods do provide protein — there are many. It’s important to educate yourself on what food groups are required to maintain adequate nutritional intake and how to do this.”
Some of the most protein-packed plant foods are:
— Soybean products like tofu, edamame and tempeh.
— Rice and beans (eaten together).
It may also be a challenge to find the type of plant-based eating plan — full vegetarian, vegan, flexitarian — that works best for you. “With the exception of some forms of cancer and digestive conditions that do better without meat or dairy, I usually let the client decide whether animal products are a part of their diet or not,” Wroe says. “Animal products can be part of a very healthy diet if the majority of foods on the plate are still plants, which is my preferred definition of ‘plant-based.'”
A full vegan diet is not recommended for children under 13, Wroe says, because of the “intense growth needs in this phase of life.” It should also be avoided by those with some autoimmune conditions and any risk of depression or anxiety. “If following a vegan diet, B12, iron, omega-3s and protein should be monitored and likely supplemented,” she says.
[READ: Vegan vs. Vegetarian.]
With the exception of some epilepsy patients, most nutrition experts warn against the keto diet. At the least, use extreme caution. “I do not recommend it long term, but in rotations of approximately three months, followed by lower carb but not keto meal plans, which can help stimulate weight loss,” Wroe says.
In fact, the healthiest way to follow a keto diet is to follow a plant-based keto diet, Wroe says. “Keto has become a trendy diet and, in doing so, it has been manipulated into a high animal fat diet that includes lots of processed meat products. Many practitioners label this as ‘dirty keto’ and it can actually have harmful health effects long term. Truly beneficial keto is a diet that is vegan, and its high-fat components come from plant fats, such as nuts, seeds, olives, avocados and oils.”
Wroe says a plant-based keto diet may also be appropriate for those undergoing chemotherapy and recovering from cancer, as well as those who may be doing a short-term, ketogenic fasting-type diet for enhanced immune and metabolic function.
Smith believes that any weight-loss intervention should be individualized and monitored by a physician or a licensed nutrition expert. “Both a keto and plant-based diet may be an effective intervention to promote weight loss in some individuals, but might not be effective for the long term in all individuals,” she says.
More from U.S. News