The ketogenic diet (keto) is changing how many people think about healthy eating. But like all diet trends, keto is more complex than it seems.
The “keto diet” refers to a broad range of low-carb eating plans. The most basic version is similar to the 1990s Atkins Diet, in which you temporarily reduce the amount of carbohydrates you eat daily, such as grains, vegetables, and fruits.
A more stringent keto plan requires eating almost no carbs and putting your body into ketosis. The body burns stored fat instead of glucose (sugar from carbs) for energy and produces a type of ketones, an acid that passes through urine.
Keto has been associated with dramatic short-term weight loss, which patients hope will improve their self-esteem, mobility, and heart disease risk. However, some people have reported unpleasant and potentially dangerous side effects, including bad breath, strong vaginal odor, kidney complications, and atrial fibrillation (heart palpitations).
"Just like not all vegetarian diets are created equal, there are unhealthy ways to do keto. That’s why it’s tough to give a simple 'yes' or 'no' when patients ask, 'Is the keto diet safe?'"
Keto has become a trendy obsession, with celebrities singing its praises and "keto food" products popping up left and right. And research suggests the diet can help with epilepsy symptoms. But just like not all vegetarian diets are created equal, there are unhealthy ways to do keto. That’s why it’s tough to give a simple “yes” or “no” when patients ask, “Is the keto diet safe?”
If you want to try keto, consider discussing three key questions with your doctor:
- What foods are replacing carbs in your diet?
- What is your goal?
- What are your personal risk factors?
3 keto questions to consider
1. What foods are replacing the carbs in your diet?
The answer to this question can indicate whether keto might be successful or potentially harmful to your health. If you replace carbs with plant-based unsaturated fats like those found in avocado, seeds, nuts, and liquid oils, and low in saturated fat proteins such as nuts, beans, fish and poultry (similar to the Mediterranean diet), you are more likely to see positive effects.
But many people who do keto replace carbs with animal-based saturated fats, such as cheese and red meat. This can increase bad cholesterol and potentially increase the risk of heart problems.
Related reading: Scale stuck? Rethink eating before and after exercise
2. What is your goal?
Patients often bring up three main reasons they want to try keto: losing weight, managing Type 2 diabetes, and lowering cholesterol, all of which are strategies to reduce heart disease risk. To help determine an effective diet, consider breaking your reasons into short-term goals such as these:
The short-term benefits of keto are documented for generally healthy patients.
- Weight loss: Keto can help some patients get over the hump to kick off a weight-loss program, which can lead to longer-term health.
- Managing Type 2 diabetes: Keto can improve the way your body processes sugar because of the significant reduction in carbohydrate intake. The typical ketogenic diet restricts carbs to 20 to 50 grams daily.
- Lowering cholesterol: Eating more unsaturated, non-animal-based fats can positively impact cholesterol levels in the short term and set the stage for healthier eating habits going forward. However, if your keto diet includes a lot of animal protein the opposite could happen.
The long-term effects are trickier to predict because we simply don’t have enough data to determine whether even the healthiest keto diet is safe or sustainable.
Most healthy people can stay on the keto diet for a few weeks without problems, but they may struggle with it in the long-term because it can be quite restrictive. Consider the following if you’re thinking about committing to keto for the long haul:
- Weight loss: We don’t know whether certain carb replacement choices or the effects of extended ketosis will do more harm than good.
- Managing Type 2 diabetes: Eating a high-protein diet over a long period of time can potentially damage the kidneys, which is already a concern for people with Type 2 diabetes.
- Lowering cholesterol: Eating more plant-based and less animal-based foods is shown to help lower cholesterol. But again, long-term ramifications of low-carb, high-fat diets are not yet known.
3. What is the patient’s risk status?
People with preexisting health conditions should consult a doctor before starting a restrictive diet like keto. For example, patients with heart disease might have different nutritional needs than people who are just a little overweight.
Start with a visit to your primary care doctor to get basic lab work and a kidney function test. If something is abnormal, the doctor can suggest ways to prevent complications or recommend another diet plan that might be more effective. Consider visiting with a dietitian as well for guidance on how to incorporate healthy foods that can help you reach your goals.
Side effects of the keto diet
When the body is used to consuming carbs and you suddenly stop eating them, you might first feel tired, have a headache, or feel a little “brain fog” for a few days. These side effects should clear up as your body adjusts. But if you experience symptoms of dizziness, heart palpitations, nausea, or changes in stool habits, check in with your doctor to see if laboratory work or diet changes are necessary.
For some patients, entering ketosis can be detrimental to health. For example, people with Type 1 diabetes can develop ketoacidosis, a condition that causes extreme illness and can result in going into a coma.
Be cautious of what you read in the news
I caution patients to consult with a doctor if they encounter stories about keto in the media. Research and reporting on the ketogenic diet vary. Some organizations report health benefits while others report only negatives. In these studies, the diet and replacement foods examined and patient characteristics are not standardized, so the data are unlikely to be apples to apples.
When it comes to improving health with nutrition, moderation is usually the key. Sometimes plans like keto can kickstart a healthier lifestyle, and the long-term benefits come when you stabilize your diet and exercise plan into a sustainable lifestyle change.
3 Key Tips for Keto Meals
Keep animal protein lean (no visible white fat, avoid skin).As much as possible, use liquid oils rather than those you have to cut or scoop - the exception being avocados and nut butters, which are heart healthy fats.Vegetarian-based keto recipes help ensure you are getting the micronutrients not plentiful in animal tissue or fat, such as potassium and vitamin C.
Susan Rodder, M.S., Nutrition
Pesto Caprese Zucchini Noodle Salad
Ingredients for pesto
2 T pine nuts
1 packed cup of basil
1.5 T olive oil
1 small clove garlic
Pinch of salt and pepper
For zucchini noodles
1 medium zucchini
2 slices of tomato
1 slice part skim mozzarella cheese
2 teaspoons olive oil to drizzle
Pinch of red pepper flakes
2 basil leaves, thinly sliced
1. Place all presto ingredients into a food processor and pulse until creamy.
2. In a large mixing bowl, toss zucchini noodles with pesto.
3. Plate zucchini noodles on two dishes and top with tomato and mozzarella slice.
4. Drizzle with olive oil and garnish with red pepper flakes and basil.