Dangers of the Keto Diet Debunked

Authored by Nate Martins •
October 8, 2018

The ketogenic diet gained popularity through the weight loss community. It’s a low-carb (often 25g per day), high-fat diet triggering the body to burn fat for energy instead of carbohydrates. It is also called ‘keto diet’ or just ‘keto’

With increased popularity, there has also been an increase in keto-naysayers; they think it’s a dangerous fad fueled by the common desire to lose weight.

“It’s unhealthy and unsustainable,” they say. “How can a high-fat keto diet help you lose weight? It’s dangerous for the heart, increases the risk of ketoacidosis, leads to poor mineral intake and electrolyte imbalance,” they say. But the ketogenic diet has a well-established history of aiding in disease treatment. It has been used to help people with epilepsy (especially children) since the early 1900’s, and more recently, it has been used to manage type-2 diabetes (since it lowers the need for insulin therapy).1

Table of Contents

“If I eat so much fat, won’t I get heart disease?”

Saturated Fats

Unsaturated Fats

Trans Fats


“You’ll get fat eating all that fat!”


Dietary Fat Doesn’t Immediately End Up as Body Fat

With all the noise surrounding the ketogenic diet, it’s difficult to know what to believe. So we’re here to set the record straight, and provide information to help make well-informed decisions about the keto diet. Below, we’ve gathered some common misconceptions about the ketogenic diet and provided answers to help cut through all that static.

“If I eat so much fat, won’t I get heart disease?”

The short answer is “no.” It’s important to note there are several different groups of fats, including trans, saturated and unsaturated.

Not all fats are created equal in the realm of disease risk.

Old school dietary conventions suggest eating fatty foods increases the risk of heart disease and lead to high cholesterol levels.

The keto diet requires ample fat to provide energy and compensate for the reduction in energy from carbohydrates. Foods that are rich in fat include meats, cheese, oils, fish, butter, cream and eggs.

Saturated Fats

These are commonly found in animal products and oils (coconut oil, palm oil, palm kernel oil, olive oil). For years, saturated fat was believed to be a key cause of heart disease. That opinion was largely based on the results of epidemiological studies, and the methodological flaws and potential biases of these studies have since come to light.2

A recent, more comprehensive study found that people who ate more saturated fat had an overall lower mortality rate and no increase in death from heart disease.3

So, getting energy from saturated fat while following a ketogenic diet doesn’t appear to be the health risk it was pegged as.

Unsaturated Fats

Avocados are the poster child of “good fats.” This type of fat, often found in plant-based foods, can be separated into polyunsaturated fats (found in fish and walnuts) and monounsaturated fats (found in avocados, flaxseed oils, nuts and seeds). There’s evidence that replacing saturated fats with “good” unsaturated fats can lower the risk of heart disease and help prevent insulin resistance.4

A recent study illustrated that switching from a carb-rich diet to a diet higher in unsaturated fats reduced cardiovascular risk, lowered blood pressure, and improved cholesterol and lipid levels.5

Trans Fats

These are harmful fats, found mostly in vegetable oils when they’re partially hydrogenated through heating. They’re also found in processed snacks, baked goods and margarine–foods to avoid on the ketogenic diet.

Interestingly, partially hydrogenated oils (PHO), which are the primary dietary source of artificial trans fat in processed foods, aren’t GRAS (generally recognized as safe) by the FDA.



Produced by the liver, cholesterol is also derived from our diet. People often assume eating foods rich in cholesterol will raise cholesterol levels and increase the likelihood of a heart attack. But it’s more complicated than that. Cholesterol-rich foods feature heavily in the keto diet (butter, eggs, red meat); but there are two types of cholesterol. “Bad” LDL cholesterol (think L = lethal) is linked to clogging of the arteries. “Good” HDL cholesterol (think H = healthy) clears cholesterol from the blood.

Research shows there is a weak relationship between levels of dietary cholesterol and blood cholesterol.6 The effect isn’t the same for everyone either. There are “responders” and “non-responders” to dietary cholesterol; some people experience higher fluctuations in blood cholesterol levels according to the amount of cholesterol they eat, while others are more stable regardless of diet.

Regarding the keto diet, experts recommend focusing not on total cholesterol levels of the food, but instead on the impact food has on LDL and HDL ratios. Consuming plenty of polyunsaturated fats increases blood HDL levels while reducing LDL. Since saturated fats and trans fats increase LDL levels, these should be reduced.

Still, it’s important to keep track of blood biomarkers when starting out on a ketogenic diet to help ensure the diet isn’t increasing risk factors for heart disease.

You’ll get fat eating all that fat!”

It may seem counterintuitive: how can a diet high in fat not lead to weight gain?

Often the biggest misconception about the keto diet: eating fat leads to weight gain or obesity.

That’s likely because we’ve been conditioned to believe eating a low-fat diet leads to weight loss. But all dietary fat doesn’t end up as belly fat.


When we eat proteins and carbohydrates, the pancreas releases insulin into the blood. Insulin is a hormone that signals to our cells to absorb nutrients (such as glucose) and to start using glucose for energy. Any excess glucose is stored as glycogen or converted into fat by the liver or specialized fat storage cells.

Insulin isn’t released when fat is consumed. Fat is absorbed in the intestines and enters the bloodstream circulation as lipoproteins. Fat is a major source of energy for the body, so much of the fat consumed in food is used to keep us alive.

Excess fat is broken down and stored as fatty acids in the liver, or as body fat. This shows that even though proteins, fats, and carbohydrates may be metabolized differently, in both mechanisms the excess food energy is stored as body fat.

Dietary Fat Doesn’t Immediately End Up as Body Fat

Instead, it should be recognized that in excess food in general–whether carbohydrates, proteins or fat–can become body fat.

Low-calorie, low-carbohydrate diets are increasingly recognized to be more satiating than low-calorie mixed diets (meaning, overall calorie intake is reduced to promote weight loss).7 Many people on the keto diet commonly experience the feeling of being more satisfied after eating, and this could contribute to weight loss–but scientists have yet to find a clear advantage of keto for weight loss when compared to any other calorie-controlled diet.


Scientific Citations

1. Hallberg, S. J., McKenzie, A. L., Williams, P. T., Bhanpuri, N. H., Peters, A. L., Campbell, W. W., Volek, J. S. (2018). Effectiveness and Safety of a Novel Care Model for the Management of Type 2 Diabetes at 1 Year: An Open-Label, Non-Randomized, Controlled Study. Diabetes Ther.
2. Keys, A. (1953). ATHEROSCLEROSIS: A PROBLEM IN NEWER PUBLIC HEALTH*‘. Atherosclerosis 1, 19.
3. Dehghan, M., Mente, A., Zhang, X., Swaminathan, S., Li, W., Mohan, V., Iqbal, R., Kumar, R., Wentzel-Viljoen, E., Rosengren, A., Amma, L.I., Avezum, A., Chifamba, J., Diaz, R., Khatib, R., Lear, S., Lopez-Jaramillo, P., Liu, X., Gupta, R., Mohammadifard, N., Gao, N., Oguz, A., Ramli, A.S., Seron, P., Sun, Y., Szuba, A., Tsolekile, L., Wielgosz, A., Yusuf, R., Hussein Yusufali, A., Teo, K.K., Rangarajan, S., Dagenais, G., Bangdiwala, S.I., Islam, S., Anand, S.S., and Yusuf, S. (2017).,Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet.
4. Riserus U, Willett W, Hu F. Dietary fats and prevention of type 2 diabetes. Prog Lipid Res. 2009 Jan; 48(1):44-51
5. Appel L, Sacks F, Carey V et al. Effects of Protein, Monounsaturated Fat, and Carbohydrate Intake on Blood Pressure and Serum Lipids. JAMA. 2005 Nov16; 294(19): 2455-64
6. Kratz, M. Dietary cholesterol, atherosclerosis and coronary heart disease. Handb Exp Pharmaco. 2005;170:195-213.
7. Adam-Perrot A, Clifton P, Brouns F. Low-carbohydrate diets: nutritional and physiological aspects. Obesity Reviews 2006 Feb;7(1):49-58.