Keto Dieting Mistake Many Dieters Make
A new comprehensive review of today's two most popular fad diets—the ketogenic diet and intermittent fasting—reveals what cardiologists believe is the dieting mistake we make while on these weight loss diets. In this article, we will take a look at what they found on how well (or not) a keto diet performs for cardiac health as well as losing weight.
Heart Disease and Dieting
Heart health experts tell us that cardiovascular disease is responsible for 33% of all deaths worldwide. However, by adopting lifestyle modifications such as a change in our dietary habits, premature death due to cardiovascular disease is avoidable and doable if we just focus more on eating fruits, vegetables, legumes, nuts, and whole grains.
In a recent paper published in The American Journal of Medicine, researchers are concerned that the recommended dietary focus of eating primarily fruits, vegetables, legumes, nuts, and whole grains has taken a backseat to what they refer to as “fad diets” like the ketogenic diet and intermittent fasting that are so popular today among dieters.
The Ketogenic Diet and Cardiac Health
To address this concern, the researchers analyzed the efficacy of the ketogenic diet by examining the impact it has on metabolic syndrome, dyslipidemia, hypertension, and impaired glucose metabolism, and how this fits in with the prevention of cardiovascular disease.
The following is a summary of what the study found:
The Obesity Factor—weight loss and keeping it off
The most important part of a ketogenic diet is sticking to a daily carbohydrate intake limited to 50 g (or ≤10% of your daily calories). Following a low carb diet results in a metabolic state in which the body has reduced access to glucose and is instead mostly fueled by fat. The more fat burned, the more weight is lost and the slimmer the body becomes. What makes this especially attractive as a weight loss measure is that the slimming results occur relatively quickly and you are allowed to eat a lot of protein to stave off hunger pain.
The ketogenic diet gained a lot of momentum when earlier studies confirmed that following a ketogenic diet does cause faster and greater weight loss in comparison to other dieting methods. However, these and similar studies have also shown that once a dieter goes off a keto diet, that a weight gain rebound occurs leading to more weight regained in comparison to other diets after the diet was discontinued.
The Lipid Factor—how cholesterol numbers fare from the diet
In general, high density lipoprotein (HDL) is considered “good” cholesterol, whereas low density lipoprotein (LDL) is considered “bad” cholesterol. HDL carries cholesterol to your liver, where it can be removed from your bloodstream before it builds up in your arteries. LDL, however, takes cholesterol directly to your arteries where it builds up as plaques and hardens the arteries.
Your total cholesterol is a measure of the total amount of cholesterol in your blood that includes both LDL, HDL along with triglycerides—another form of fat that is part of a lipoprotein panel used in measuring cholesterol levels.
With the keto diet, the study found that a review of past literature shows that the ketogenic diet demonstrates inconsistent improvements in LDL or total cholesterol. However, there is some evidence for a benefit of the keto diet to raise HDL and lower triglyceride numbers.
The Blood Pressure Factor—is it the keto or something else?
The researchers found that a number of studies do associate the keto diet with lowered systolic and diastolic blood pressure numbers. However, whether the lowering is directly attributable to the ketogenic state is unknown as studies have associated a lowering of blood pressure numbers to other low-carb dieting conditions.
The Glucose Metabolism Factor—how diabetes patients respond to keto
Because a keto diet restricts dietary carbohydrates, the ketogenic diet is expected to be beneficial in the prevention and treatment of type 2 diabetes mellitus.
What the researchers found was that the ketogenic diet does appear to benefit those at risk for or with type 2 diabetes by improving their glucose metabolism.
The Cardiovascular Disease Factor—a prevention possibility
Animal studies have shown that ketone bodies appear to have a cardioprotective effect that results in less infarction during an ischemic event.
With humans, studies show that ketone bodies allow cardiac myocytes to become more ‘energy efficient’ by reducing fatty acid oxidation and oxygen consumption, while improving contractility—resulting in improved myocardial function and a decreased incidence of cardiovascular events. Furthermore, a reduced carbohydrate intake is associated with a reduced risk for cardiovascular disease; however, studies that meet the ketogenic criteria are needed to specify this effect.
The Adverse Effects Factor—insulin, inflammation and fibrillation (Oh my!)
According to the researchers’ findings, there are some potential adverse effects with a ketogenic diet that include an association with:
• Insulin resistance and preventing the suppression of endogenous glucose production by insulin.
• Ketone body association with increasing membrane excitability and arrhythmogenesis, possibly increasing the risk of atrial fibrillation.
• Potential cardiac chamber enlargement from consuming a ketogenic diet.
• Ketogenesis has demonstrated an increase in various inflammatory markers in both animal and human studies.
The Researchers Take-Home Conclusion for Dieters on the Keto Diet
The authors of the study acknowledge that the keto diet does appear to have short-term benefits with respect to improved cardiometabolic risk factors such as obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance. However, they note that the long-term effects of being on a keto diet are unknown, but that the keto diet is expected to be problematic due to its dietary restrictive nature.
One take-home message for dieters on a ketogenic diet is the warning that many dieters may be consuming way too much of saturated fats and animal products such as red meat, which are known to increase the risk for cardiovascular disease, kidney disease, and cancer.
The authors write that “The restrictive nature of the diet might lead to an unregulated intake of foods that are known to cause harm. Therefore, the recommendation to start the ketogenic diet for patients must be made prudently, as this dietary approach will likely not be appropriate for most people. In patients who are meticulous, disciplined, and motivated, the ketogenic diet might be a reasonable approach to employ for cardiovascular disease prevention.”
In other words, their recommendation is that if you are on a keto diet, to be sure to focus on eating non-animal fat foods. Animal fats contain a higher proportion of saturated fats, which lead to increased bad cholesterol levels, insulin resistance, type 2 diabetes, and cardiovascular disease. The much healthier fat options are foods with monounsaturated fatty acids and polyunsaturated fatty acids that are found in nuts, seeds, avocados, olives, and oils made from plants like sunflowers, olives, soybean, and safflower.
Timothy Boyer has a Ph.D. in Molecular and Cellular Biology from the University of Arizona. For 20+ years he has been employed as a freelance health and science writer. Today, with an eye on the latest news, Timothy continues writing about science with a focus on what you need to know for healthier living. For continual updates about health, you can also follow Timothy on Twitter at TimBoyerWrites.
Image Source: Courtesy of Healthguru from Pixabay
Reference: “From Fad to Fact: Evaluating the Impact of Emerging Diets on the Prevention of Cardiovascular Disease” Melroy S. D'Souza, MD, et al. The American Journal of Medicine June 18, 2020.