Dr. Julie Chen is a board-certified internal medicine physician with the Mid-Atlantic Permanente Medical Group. She sees patients at the Kaiser Permanente Gaithersburg Medical Center.
Patients always ask me about the latest trends in dieting. They want to know the healthiest and quickest way to lose weight, and they ask about diet plans they’ve seen mentioned on social media, promoted by influencers, or they’ve heard about from a friend.
As a diplomat of the American Board of Lifestyle Medicine, I applaud patients for talking to their doctors about diet options. While some diet plans truly are healthy – such as a reduced-calorie Mediterranean diet – others can cause more harm than good.
That sentiment was reflected in new research presented at the American College of Cardiology’s Annual Scientific Session together with the World Congress of Cardiology. The research showed that a keto-like diet may be associated with higher levels of bad cholesterol and an increased risk of cardiovascular events such as chest pain, blocked arteries requiring stenting, heart attacks, and strokes.
With millions of Americans following a low-carb, keto-like diet, this is troubling. I encourage patients to discuss their eating habits with their physicians and to steer clear of ketogenic diets.
What Is a Keto Diet?
A keto diet is essentially a diet that severely minimizes all sources of carbohydrates and instead focuses on fats, with a ratio of fat to carb plus protein of 3:1 or 4:1. People on this diet plan tend to limit carbohydrates to no more than 50 grams a day. Feeling as if they have the freedom to eat any fat they want, people following a keto diet tend to gravitate toward eating a lot of red meat and high-fat dairy and butter, which are high in saturated fat.
When the body does not have sufficient sugar (glucose) available from carbohydrates as a source of energy, it goes to the next available energy source, which is fat. The liver turns fat into ketones, an acid our cells can use for fuel. This is called ketogenesis. It’s believed that because the body is using fat for energy production, patients will lose more weight; however, the benefit of losing weight in this way is overshadowed by negative features of the keto diet.
Yes, it is true that patients on a keto diet will lose weight. However, because they feel liberated to eat any type of fat, they generally eat a lot of saturated, unhealthy fats such as those found in fatty cuts of pork, like bacon, hamburgers, and steak. They also gravitate toward high-fat cheeses and other dairy products. These fats are converted in the bloodstream into bad cholesterol, also known as low density lipoproteins. And those are the blood lipids that cause cardiovascular disease. Anyone with high levels of LDL is at greater risk of having a heart attack or stroke.
Complex Carbohydrates Are Healthy
Carbohydrates often get a bad reputation, but they are considered part of an overall healthy diet. There are two main types of carbohydrates: unhealthy, simple carbohydrates, and healthy, complex carbohydrates. Simple carbohydrates are found in processed foods, such as many packaged desserts, white bread, white pasta, white rice, and white potatoes. These starchy foods are quickly broken down by the body and in excess, they are stored as fat.
In contrast, complex carbohydrates are high in fiber. Foods include whole grain breads, oats, brown rice, kale, broccoli, and avocado. The body uses these carbohydrates as fuel sources in a healthy way. Some of these foods, such as fruits, oats,and nuts like walnuts and peanuts even have been shown to decrease LDL levels.
Keto Diet and Your GI Health
The study found that those on a keto-like diet had significantly higher levels of LDL cholesterol and, during a long-term follow-up, those on the keto diet had more than a two times higher risk of having a major cardiovascular event, such as a heart attack, stroke, or peripheral arterial disease.
I would add that not only are people at greater risk of heart problems when following a keto diet, they also are at risk of gastrointestinal problems. When people don’t eat enough high-fiber foods, such as foods containing complex carbohydrates, they are doing their guts a disservice. A low-fiber diet has been linked to constipation, diverticulitis, and other gastrointestinal conditions.
A keto diet can also put followers at risk for colon cancer, which has been on the rise in younger people. Part of the reason for this alarming trend is believed to be the quantity of processed and fatty foods eaten, including lunch meats and foods that are high in preservatives.
Following a strict keto diet can lead to nutrient deficiencies, such as nutrients that are important for bone health like calcium and other micronutrients. This leads to increased bone breakdown and decrease in bone metabolism, ultimately leading to decrease in bone density.
Choosing the Mediterranean Diet
I tell patients that the keto diet is not a good solution for losing weight. Though it may work in the short term, the long-term negative effects of the keto diet outweigh the benefits of losing a small amount of weight.
In contrast, a diet such as a calorie-reduced Mediterranean diet — which is more balanced and allows a combination of lean meats or lean protein sources as well as complex carbohydrates and healthy fats — is a better choice. The fats in a Mediterranean diet are mainly unsaturated and high in omega-3 fatty acids — fats that may protect the heart.
Those interested in following a Mediterranean diet should eat fruits, vegetables, whole grains, and unsaturated healthy fats found in olive oil, avocados, seeds, and nuts. Fish is recommended a few times a week, particularly fish high in omega-3 fatty acids such as salmon, herring, and tuna. People on a Mediterranean diet limit red meat, sweets, and saturated fats.
Living a Healthy Lifestyle
In addition to eating a healthy, well-balanced diet, I always encourage patients to exercise regularly and to stay up to date on their preventive care screenings, such as cholesterol and blood sugar checks, mammograms, and colon cancer screenings.
Stress reduction is also an important component of healthy living and losing weight: People tend to eat more when they are stressed, and they tend to reach for comfort foods like sweets and chips that are less healthy.
I don’t recommend the keto diet because it’s not a sustainable diet that contributes to a healthy lifestyle. Focusing only on eating meat and fat is counterintuitive to any physician who has studied medicine, nutrition, and healthy outcomes. And the keto diet is particularly dangerous for those who already have an increased risk of cardiovascular disease, such as those with a family history of cardiac disease or patients with diabetes, hypertension, high cholesterol, chronic kidney disease, or a family history of colon cancer.
I encourage everyone to be aware of fad diets and to remember that the latest fad might not be the healthiest for your body and can negatively impact your quality of life and longevity. If you have any questions about what kind of meal plan is right for you, reach out to your physician.
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