There has been a lot of buzz surrounding Vegan Keto diets. Since April of 2017, ketogenic diets have been trending on Google and social media. Several celebrities have stated that they swear by a keto diet. But is is safe? What does the science have to say about it?
What Is Ketosis?
Ketosis is a normal metabolic process. When your body doesn’t have enough carbohydrates from food for energy, it burns fat instead. Basically, when there isn’t a sufficient level of glucose in your blood and glycogen levels are depleted, the body looks for an alternative source of fuel and that fuel is fat.
When your body doesn’t have enough fuel for energy, it breaks down fat for fuel. The process is called beta-oxidation wherein fatty acid molecules are broken down and there is an increase in acetyl-CoA (the molecule used for protein, carbohydrate and lipid metabolism for energy production). When there is an increase in acetyl-CoA, it then enters what is called the citric acid cycle (a.k.a. the Krebs cycle) in the mitochondrion by combining with Oxaloacetic acid to form citrate / citric acid. Citrate is a key intermediate in metabolism. Citrate will then cause the spontaneous breakdown of acetoacetate (otherwise known as a ‘ketone body’) which is produced by the liver, and then will be used as your energy source.
Ketosis Burns Fat
Consider a hibernating animal such as a bear or squirrel. They ‘fatten up’ during the year, and hibernate in the winter so they don’t freeze to death. During hybernation, animals use the stored fat as fuel. The metabolic process used to fuel them during hybernation is ketosis. They use several metabolic processes including ketone bodies to keep them alive. Because there are extreme reductions in heart, respiratory, and metabolic rates, the use of ketone bodies happens very slowly so that their blood does not become too acidic.
It is thought that ketone bodies is what fueled our ancestors during lean times. In other words, when there was famine or lack of food, ketone bodies were burned for fuel. It is important to note that ketosis is a STATE OF STARVATION.
Ketosis Is Difficult To Acheive And Very Restrictive
On a ketogenic diet, you are getting 80-90 percent of your calories from fat. You’re only allowed 10 to 35 grams of carbohydrates per day, and though many try to stretch that to 40 or 50 grams per day that’s still only about one banana or one apple.
In addition to the fat and carbohydrate content of a keto diet, if you give your body more than the absolute minimum amount of protein that it needs, it will immediately break proteins down into carbohydrates.
As a vegan, eating all plant matter, it is more likely that you would be on a low carbohydrate, high fat (LCHF) diet.
The Science on LCHF vs. Low Fat
There are several different types of studies when considering diets and nutrition. There are observational studies, large analysis of many studies, epidemiology studies (the study and analysis of the distribution (who, when, and where) and determinants of health and disease conditions in defined populations), and randomized control trials (RCT’s). RCT’s are considered the most rigorous, so for the purpose of this article I will only use RCT’s to demonstrate the lack of effectiveness of LCHF diets vs. other diets.
In the following RCT that was ironically commissioned by Gary Taubes (a LCHF proponent) the scientists concluded that: Cutting carbohydrates increased net fat oxidation, but cutting fat by equal calories had no effect. And that cutting fat resulted in more body fat loss as measured by metabolic balance.
Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity https://www.cell.com/cell-metabolism/fulltext/S1550-4131(15)00350-2
In the following RCT, the scientists primary objective was to determine the effect of a healthy low-fat diet vs a healthy low-carbohydrate diet on weight change. At the end of this 12-month weight loss diet study, there was no significant difference in weight change between a healthy low-fat diet vs a healthy low-carbohydrate diet.
Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. https://www.ncbi.nlm.nih.gov/pubmed/29466592
Vegan Diets vs. Other Diets
Again using only RCT’s, here are the effects of a low fat plant based diet vs. other diets.
The aim of the following study was to determine the effect of plant-based diets on weight loss. They compared 5 different diets and their conclusion was: Vegan diets may result in greater weight loss than more modest recommendations.
Comparative effectiveness of plant-based diets for weight loss: a randomized controlled trial of five different diets. https://www.ncbi.nlm.nih.gov/pubmed/25592014
In this study, the objective was to assess the effect of a low-fat, vegan diet compared with the National Cholesterol Education Program (NCEP) diet on weight loss maintenance at 1 and 2 years. They conclude that: A vegan diet was associated with significantly greater weight loss than the NCEP diet at 1 and 2 years.
A two-year randomized weight loss trial comparing a vegan diet to a more moderate low-fat diet. https://www.ncbi.nlm.nih.gov/pubmed/17890496
Side-Effects and Downfalls of Ketogenic Diets
It is important to note that long term ketosis is not a natural state for humans or any other species. I am not going to go into massive scientific detail as far as the side-effects are concerned. Here are the things you need to be concerned about:
- Loss of salt (hyponatremia)
- Keto-flu (carbohydrate withdrawal symptoms include dizziness, drowsiness, muscle aches, nausea, and irritability)
- Changes in bowel habits/ constipation
- Leg cramps due to the lack of potassium and magnesium in the diet
- Bad breath
- Loss of energy and fatigue due to extreme calorie restriction
- Brain fog / slow thinking
- Racing heart rate when lying down
- Severe cravings
- Blood acidity
- Increased risk of bone fracture (Circulating ketone bodies make your blood too acidic, and your body will draw calcium from your bones as a buffer)
- Kidney stones (ketosis will raise your uric acid levels, lower your citric acid levels, and increase your oxalate levels which will cause kidney stones, especially when using animal proteins on a keto diet).
- Fatty liver (Non-alchoholic fatty liver disease NAFLD is directly related to saturated fat intake.Reference below)
Isocaloric Dietary Changes and Non-Alcoholic Fatty Liver Disease in High Cardiometabolic Risk Individuals https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5691682/
Saturated Fat Is More Metabolically Harmful for the Human Liver Than Unsaturated Fat or Simple Sugars http://care.diabetesjournals.org/content/early/2018/05/24/dc18-0071
- Muscle Loss – Not only will you break down fat on a keto diet, because of the minimal protein you will also lose muscle mass.
Isocaloric carbohydrate deprivation induces protein catabolism despite a low T3-syndrome in healthy men. https://www.ncbi.nlm.nih.gov/pubmed/11167929
- Microbial imbalance (loss of diversity in gut microbiome)
- Possible sudden cardiac death!
Sudden cardiac death in association with the ketogenic diet. https://www.ncbi.nlm.nih.gov/pubmed/19027591
- Uncontrolled ketosis (ketoacidosis) can lead to a sharp, and potentially fatal, increase in the acidity of the blood.
- Saturated fat increases LDL cholesterol and increased risk of cardiovascular disease.
Saturated Fat And Dietary Cholesterol Matters
The one thing that is most upsetting about the information – or shall I say misinformation about LCHF and keto diets – is that dietary cholesterol and saturated fats don’t matter. The people that push for the LCHF and keto diets are constantly barraging the internet and the news headlines with misinformation. I have looked at the studies referenced in these publications and books very deeply and I can tell you that they are industry (meat, dairy, avocado) funded studies with skewed baselines and controlled measures in order to predict the outcome and cause the outcome to reiterate their false narratives.
I am not going to delve too deeply into this topic today, but I want to point out a couple of consensus statements from reputable organizations:
Just this year (June 2018), the European Atherosclerosis Society Consensus Panel did a a VERY comprehensive review of the evidence that LDL cholesterol causes heart disease. They looked at several large meta-analyses of prospective observational epidemiology studies with data from 1,194,767 participants in the studies. They reviewed the evidence from Mendelian randomization studies involving more than 300,00 participants. They reviewed the compelling evidence from randomized clinical controlled trials including almost 170,000 individuals. Their conclusion:
- Considered together, the strong and consistent evidence from the genetic studies, prospective epidemiologic cohort studies, Mendelian randomization studies, and randomized intervention trials discussed here, supported by mechanistic evidence [sic], establishes that LDL is not merely a biomarker of increased risk but a causal factor in the pathophysiology of ASCVD (Atherosclerotic Cardiovascular Disease).
Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel – https://academic.oup.com/eurheartj/article/38/32/2459/3745109
Last year, the American Heart Association reviewed the scientific evidence (including recent studies) on the effects of dietary saturated fat intake – and its replacement by other types of fats, as well as carbohydrate intake – on cardiovascular disease. They looked at randomized controlled trials that lowered the intake of dietary saturated fat and replaced it with polyunsaturated fats, and they found that replacing the saturated fat with polyunsaturated fat reduced CVD by around 30%!! They state:
Replacement of saturated with unsaturated fats lowers low-density lipoprotein cholesterol, a cause of atherosclerosis, linking biological evidence with incidence of CVD in populations and in clinical trials.
Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association http://circ.ahajournals.org/content/early/2017/06/15/CIR.0000000000000510
Is There A Safer Weight Loss Method?
The answer is YES. All you have to do is have a calorie deficit. It isn’t rocket science. This is why people lose weight on a plant-based, or keto, or Weight Watchers diet, etc.
In this extremely balanced BMJ (formerly British Medical Journal) Commissioned paper was just published 13 June 2018, and was written by unbiased authors from 3 Continents. The authors make it clear about diet and the role of CALORIES in obesity. In short, it’s not one food that is the culprit for obesity.
Here is what the paper states:
“The energy equation – that calories consumed=calories expended +/- calories stored (as body fat or glycogen)—is always true.”
Making progress on the global crisis of obesity and weight management https://www.bmj.com/content/361/bmj.k2538
In addition to a calorie deficit and increased energy expenditure (exercise), there are other ways to kick-start your metabolism. Fasting has tremendous benefits on metabolism and longevity. Although fasting can be difficult, a Fasting Mimicking Diet as designed by Professor Valter Longo may be an easier alternative than a water only or juice fast. More info on FMD here.
Weight Loss On A Whole Food Plant-Based No Oil Diet
In my opinion, and due to the scientific literature, the easiest way to lose weight is with a low fat, whole food plant-based diet. I have personally lost over 160 pounds / 73kg this way and know MANY others that have. Eating a well balanced, low fat, whole food-plant based diet does not cause the many side effects mentioned above and will not cause ASCVD!
This is me before and after!
Here are my ‘Easy Weight Loss On A Plant Based Diet‘ tips. Note, I lost this weight on a HIGH CARB diet!
Read testimonies from many other people that have lost weight on a low fat, whole food plant-based diet on my page “Plants Heal Humans“.
Further Reading On Ketogenic Diets
This is a guest post by Dr. Michelle McMacken – ‘5 Reasons Why I Don’t Recommend A Keto Diet‘.
I wrote this post about Ketogenic Diets. It has references to over 1200 scientific studies. ‘Why I Hate The Ketogenic Diet Craze‘.
If you would like more information on the vegan ketogenic diet, and fasting, I would encourage you to follow Dr. Joel Kahn. Dr. Kahn is a cardiologist and is very knowledgeable about the vegan ketogenic diets, fasting, and the effects of saturated fats on mortality and heart disease:
As always, if you have ANY questions about my content, please do not hesitate to reach out to me directly.
Let Food Be Thy Medicine!
In Good Health,
4 Replies to “Is a Vegan Keto Diet Safe?”
A very good and eye opening article. I think many of the so-called positive articles about the keto diet comes from short term weight loss and cholesterol numbers. But most studies show that this begins to reverse and turn to ill health after about 6 months of being on a keto diet.
Unfortunately – there are NO long term studies on a ketogenic diet.
I realized more something totally new on this weight loss issue. One issue is a good nutrition is tremendously vital when dieting. A huge reduction in bad foods, sugary foods, fried foods, sweet foods, beef, and white colored flour products might be necessary. Retaining wastes organisms, and harmful toxins may prevent targets for shedding fat. While specific drugs temporarily solve the condition, the awful side effects will not be worth it, they usually never supply more than a short-term solution. It’s a known incontrovertible fact that 95 of diet plans fail. Thanks for sharing your thinking on this site.
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