Keto or Plant-Based?
Given the recent popularity of the ketogenic (“keto”) diet, I’ve had a lot of patients inquire as to whether or not this method of eating is beneficial for weight loss and long-term health. In general, I advocate a plant-based diet which tends to be higher in non-refined carbohydrates due to incorporation of a broad spectrum of fruits, vegetables, legumes, and whole grains. With a plant-based diet, it would not be unusual to have 40-60% of consumed calories come from carbohydrates, 30-40% from healthy polyunsaturated and monounsaturated fats (preferably in their whole-food form), and 20-30% from plant-based protein sources. There are numerous population studies and randomized control trials which consistently demonstrate the benefits of plant-based diets in significantly reducing the incidence of the chronic illnesses which cause the most morbidity and mortality in our country. These include coronary artery disease, stroke, and diabetes in particular. Long term, following a plant-based diet is also associated with weight loss, improved cholesterol profiles, and stabilization of blood sugar and insulin levels. In evaluating the Blue Zone populations, those with the largest number of people living healthy lives into their 90s and 100s, dark leafy greens and some variation of legume are consistently among the most prevalent foods consumed. This blog post from the Plant Proof website does a nice job summarizing some of these principles.
A ketogenic diet, on the other hand, is a diet which traditionally includes 75% of calories consumed from fat, 20% from protein, and only 5% from carbohydrates. Much of the fat is saturated as it comes from animal sources (including large quantities of processed meats and cheeses in the US). Ingestion of saturated fats has typically been associated with higher risks of cardiovascular disease, although more recent literature questions this and suggests more of a neutral effect. Reducing carbohydrates to less than 50 grams (5% assuming a 2000 calorie diet) excludes a broad spectrum of plant-based foods, potentially depriving an individual of disease-fighting fiber, antioxidants, and phytonutrients. Unfortunately there are no long-term population or randomized studies published which review the cardiovascular health benefits or harms specifically of a ketogenic diet. A small randomized study published in 2009 suggested that a low-carbohydrate plant-based diet has cholesterol-lowering advantages over a high-carbohydrate, low-fat weight-loss diet. A 2013 analysis of 17 studies showed a 30% increase in mortality in those consuming a low carbohydrate diet. What does seem to be clear is that the diet is good for short-term weight loss and stabilization of blood sugar. There does seem to be a plateau, however, and because of the restrictive nature, it is difficult to maintain this method of eating long term. It is also difficult in general to follow a diet which incorporates the principles of both plant-based and ketogenic philosophies.
For those that want to include a ketogenic way of eating, but still want to benefit from the known favorable effects of a plant-based diet, it is possible to combine the two, although it takes meticulous planning (Myfitnesspal is a great app to calculate the amount of fats, carbohydrates, and proteins in your food). Some more flexible options include a modified ketogenic diet which allows ingestion of a greater number of carbohydrates (100-150 grams), intermittent ketogenic diet (strict keto for 2-4 weeks every couple of months alternating with more traditional plant-based diet the remainder of the time), and cycling of strict ketogenic diet with a plant-based diet on different days of the week (for instance consuming more carbohydrates/plant-based on more active days and more ketogenic on less active days). Additionally, intermittently fasting for 14-16 hours (for instance only eating between 10 AM and 6 PM) every day or most days of the week allows some degree of ketosis which can contribute to some of the favorable effects of weight loss and fat burning without having to fully adopt a strict ketogenic diet.
What Exactly Is a Ketogenic Diet?
The ketogenic diet actually has a 100-year-long history. In the 1920s, physicians used a ketogenic diet to treat epilepsy in children. Since then, it has been found to have other health benefits such as improved insulin sensitivity and weight loss (including fat loss).
During ketosis, the body uses fat for energy. The body’s preferred fuel source is glucose, which is the easiest molecule for it to convert into energy. This glucose comes from dietary carbohydrates. This is an efficient system for those who eat well-balanced diets with healthy ratios of fats, carbohydrates, and proteins, however many people eat too many refined carbohydrates, sugars, and processed fats. Such high-carb diets lead to the overproduction of glucose. In this setting, the body uses whatever glucose it needs for energy. The remaining glucose then gets stored in the liver as glycogen. If there’s any that’s left after that, the body converts it and stores it as fat. This leads to weight gain, diabetes, fatty liver, and the accompanying health conditions.
With the ketogenic diet, you dramatically lower your intake of carbohydrates and increase your intake of fats. As a result of this carbohydrate-limiting diet, the body no longer has the glucose it needs for energy. So it seeks out fat as an alternative energy source.
Fat starts to get broken down into ketone bodies (ketones for short), which generate energy and continue to do so until carbohydrates are reintroduced and glucose can once again be used. If that doesn’t happen, it will keep burning fat reserves indefinitely.
When you don’t eat copious amounts of carbohydrates, levels of insulin, the hormone that controls blood sugar, remain much steadier than they do on the carbohydrate-based diet most people are used to
What Is A Vegan/Vegetarian Diet and can this be keto?
Vegans consume no animal products. Like vegetarians, they don’t eat meat, poultry, or fish but they also avoid dairy, eggs, and other foods that contain even trace amounts of animal ingredients. A vegetarian keto diet (ovo-pescatarian) may include seafood and eggs.
Ketogenic diets generally limit carbohydrate intake to about 5% of their daily calories while keeping protein intake at around 20% and fats at 75%. (C5, F70, P20).
Because ketogenic diets can be very restrictive, making them difficult to follow long-term, a modified keto diet is also an option. This offers many of the same benefits as a standard ketogenic diet. With Mod Keto, carbs are raised to about 20% of your total caloric intake, protein to 20–40%, and fat is reduced to 40–60% (C20, F40-60, P20-40). While not this may not lead to the same state of ketosis, the higher protein and carb allowance supports workouts and activity better while still stabilizing blood sugar and promoting fat burning.
A vegan/vegetarian ketogenic diet is one which essentially promotes eating higher-fat, lower-carbohydrate foods that are devoid of animal products. In general, fats will be the heart-healthy polyunsaturated and monounsaturated varieties rather than saturated fat typically found in animal based foods. If you include seafood, you will also be consuming essential omega-3 fatty acids. By avoiding processed foods and oils, you will avoid pro-inflammatory omega-6 fatty acids as well as unhealthy trans-fats.
What Can I Eat on a Vegan Keto Diet?
The general focus is on consuming copious plant-based fats, some plant-based proteins, and minimizing carbohydrates. The list below contains foods that fit into a vegan-keto diet (borrowed from Onnit). Good protein sources are marked with a “p”, while foods that have a higher-carb content (and should, therefore, be eaten sparingly) are marked with an asterisk (*).
- Brazil nuts
- Macadamia nuts
- Pine nuts*
Nut & Seed Butters
- Almond Butter
- Coconut butter/coconut manna (“meat” of the coconut)
- Hazelnut butter
- Macadamia nut butter
- Peanut butter
- Pecan butter
- Sunflower seed butter
- Tahini Walnut butter
Other Whole-Food Fat Sources
Healthy Oils (consumption of all oil should be limited as part of a whole-foods plant-based diet as they are all processed)
- Almond oil
- Avocado oil
- Cacao butter
- Olive oil
- Coconut oil
- Flaxseed oil
- Hazelnut oil
- Macadamia nut oil
- MCT oil
- Artichoke hearts
- Bell peppers
- Bok choy
- Brussels sprouts*
- Daikon radish
- Dandelion greens
- Lettuce (all types)
- Mustard greens
- Swiss chard
Sauces & Condiments
- Chili sauce
- Hot sauce
- Soy sauce/tamari
- Tomato sauce
Vegan Keto Fridge Staples
- Apple cider vinegar
- Dairy-free yogurt*
- Dairy-free cheese*
- Sprouts (all kinds)
- Tempeh (p)
- Tofu (p)
Vegan Keto Pantry Staples
- Almond flour
- Artichoke hearts
- Baking powder
- Baking soda
- Coconut flour
- Coconut milk (canned, full fat)
- Cocoa or cacao powder
- Dark chocolate (85% and up)
- Hearts of palm
- Jackfruit (green, canned in brine)
- Psyllium Husk
- Nutritional yeast
- Vanilla extract (most brands OK, but check for sugar)
Other Vegan Keto Meal Staples
- Herbs and spices
- Kelp noodles
- Kelp flakes
- Lupini beans*(p)
- Shirataki noodles
- Nori sheets
- Roasted seaweed
Foods You CAN’T EAT On A Vegan Keto Diet (can include Fish/Eggs if Vegetarian ovo-pescatarian***)
- Meat, fish***, poultry, dairy, eggs***, other animal products
- Sugar (refined, cane, honey, corn syrup, and all other forms)
- Grains (wheat, pasta, rice)
- Legumes (beans)
- Starchy vegetables (yams, potatoes)
- High-carb nuts (chestnuts, cashews, pistachios)
- Partially-hydrogenated oils (trans fats)
- Refined vegetable oils**
**Even though they’re not derived from animals and are high in fat, oils such as canola, corn, rapeseed, and margarine are highly processed and have a poor ratio of omega-3 to omega-6 fatty acids. They promote inflammation in the body. Because they have low smoke points, these oils are also terrible choices for cooking. High heat will turn the fats in the oil rancid, and make it even more unhealthy, causing damage to your heart, neurological problems, and other health woes.
***Try to consume organic eggs and focus on SMASH fish: Salmon, Mackerel, Anchovies, Sardines, and Herring.
How Do I Limit Carbohydrates?
In general, strict keto dieters should consume between 25-50 grams of carbs a day to achieve ketosis. The modified keto approach allows two to three times as many, but it’s still very low-carb compared to the diet of the average American. A good start would be cutting out grains, rice, bread, and pasta. Typically, you’ll also need to limit consumption of most fruits and starchy vegetables as well. Some good carbohydrate alternatives include substituting spiralized zucchini noodles or shirataki noodles for pasta, riced cauliflower for rice, or almond flour based bread for traditional grain-based bread.
Can I Get Enough Protein?
If protein is to account for 20% of your calories, based on a 2000 calorie-a-day diet, 400 calories should be attributable to protein. At 4 calories per gram, this comes out to roughly 100 grams of protein (which is a bit more than the 60-70 grams we typically recommend consuming with a plant-based diet). With a higher carbohydrate, traditional plant-based diet, beans (and even grains like quinoa) act as significant protein sources. These have too many carbohydrates for a ketogenic diet, and you must rely more on protein from nuts, seeds, and soy (tofu, tempeh, natto, etc.). For those eating a vegetarian (ovo-pescatarian) rather than vegan variation, fish (particularly fatty fish such as salmon) and eggs are good sources of protein.
Your best bet for low-carb vegan protein may be hemp seeds, which provides 30 grams of protein and 8 frams fiber (NOT counted as carbs) in a mere half cup (but this comes with a lot of calories). Seitan, which is made from wheat gluten, is another good choice and offers about 18g protein and 2g carbs every three ounces.
While not considered “whole foods”, there are protein powders that can be used to supplement protein intake. These typically come from hemp and other vegan-sourced protein powders such as rice and pea, which have about a 5:1 protein-to-carb ratio.
Vegan Substitutes for the Keto Diet
Below you will find easy vegan substitutions for foods commonly consumed in a traditional ketogenic diet. Also, remember to check labels for the presence of added sugar and carbohydrates (borrowed from Onnit).
|Milk||coconut milk, almond milk|
|Butter||coconut oil/vegan butter|
|Eggs (for cooking)||flax seed (add water in a 1:3 ratio)|
|Eggs (for meals)||Silken tofu, Veggies|
Grains and starches
|Sandwich bread||lettuce wraps|
|Pasta||Shirataki noodles, zucchini noodles|
|Mashed potatoes||Cauliflower mashed potatoes|
|Oatmeal||“Noatmeal” (made with coconut flour, coconut butter, protein powder)|
|Cereal||Chia pudding, flax granola|
|Pancakes||Peanut butter pancakes|
|Waffles||Almond flour waffles|
|Chips||Dehydrated vegetables (including kale chips)|
|Crackers||Chia seed crackers|
|Ice cream||avocado ice cream, low-carb sorbet|
|Brownies||(macadamia nut, avocado, almond flour)|
Heffernan, Andrew. The Complete Vegan Keto Diet and Food List. www.onnit.com. March 27, 2018.
Sinatra, Stephen, MD. The Ketogenic Diet: Fabulous or Fad. www.heartmdinstitute.com.
Kosinski, Christophe et. al. “Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies”. Nutrients. 2017. 9; 516.
Hill, Simon. “A Vegan or Plant-Based Diet versus Keto Diet”. Plant Proof. https://plantproof.com/a-vegan-or-plant-based-diet-vs-keto-diet/.
Noto, H et al. “Low-carbohydrate diets and all-cause mortality: a systematic review and meta-analysis of observational studies”. PLoS One. 2013; 8(1): e55030.
Jenkins, DJ. “The effect of a plant-based low-carbohydrate (“Eco-Atkins”) diet on body weight and blood lipid concentrations in hyperlipidemic subjects”. Arch Intern Med. 2009 Jun 8;169(11):1046-54.