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Should I Try a Keto Diet?

Sharon Palmer

The keto diet is the hottest weight loss diet these days. But is it a healthful, effective diet worth trying? I’m dishing my best advice today, as I answer your top questions about whether you should try the keto diet.

Question: Are there any health benefits to the keto diet? –Courtney


The ketogenic (“keto”) diet has gone mainstream! If you’re tempted to try it, here’s what you should know about this fad diet.

What is a Keto Diet? It is an extremely low-carbohydrate, very high-fat diet which has been touted for  multiple benefits, including weight loss and diabetes treatement. It contains fewer than 35 grams of carbohydrates per day, and is unlike a typical low-carb diet which is high in protein—instead it focuses most of its calories on fat.

What Does a Keto Diet Do? The keto diet forces the body into ketosis—a metabolic state in which the primary source of fuel for the body is from fat in the form of ketones. The body’s normal condition is to use carbohydrate (glucose) as its preferred energy source, which doesn’t occur during ketosis.

What’s the Diet Like? Many people who follow a keto diet don’t really achieve ketosis because it is so difficult to adere to the allowed amount of carbohydrate. To achieve that level of carbohydrate intake, virtually all grains, pastas, breads, beans, lentils, sugars, starchy vegetables, and almost all fruit are excluded. Instead, keto dieters push up the meat, full-fat dairy, eggs, nuts, seeds, and oils.

What Are the Effects of the Keto Diet? The difficulty of this diet and the restriction of foods typically leads to weight loss. However, the long-term effects of eating extremely high-fat diets and achieving a state of ketosis are unknown. In addition, a body of research suggests that eating more whole grains, beans, vegetalbes, and fruits reduces risks of chronic diseases. The keto diet suggests avoiding these healthy foods. In addition, once you go off the keto diet and return to your usual eating behaviors, weight regain may likely occur. The bottomline: The keto diet is a fad diet with many health concerns. Even though it may promote weight loss, there are more healthful ways to do so.

What Are Some Side Effects of the Keto Diet? The side effects of the keto diet include:

  • Difficulty to follow, and individual reaction to the diet may mean that each person has to tailor the diet specifically to achieve ketosis.
  • Patients with kidney disease may worsen their conditions.
  • Bad breath, fatigue, nausea/vomiting, constipation, irregular menstrual cycles, potentially decreased fertility, decreased bone density, headaches, and sleep problems have been reported as side effects of the keto diet.
  • We don’t know for sure the effects on blood cholesterol; some studies show increases, while others show decreases. We don’t know over the long-term because of a lack of research. There is a fear among health experts that such high intakes of unhealthful fats would have a long-term negative effect. Weight loss can often confuse the data in the short term, because weight loss—no matter how it is achieved—produces beneficial effects on blood lipids and blood glucose levels.
  • The extremely low to zero intake of fruits, vegetables, grains, and legumes means that people are seriously missing out on fiber, vitamins, minerals, and phytochemicals, which has significant human health impacts over the long term, such as bone loss, and increased risks of chronic diseases. Hundreds of studies suggest that diets rich in whole plant foods are linked with significantly lower levels of diseases like osteoporosis, Alzheimer’s disease, heart disease, cancer, and type 2 diabetes.
  • Constipation would be an immediate reaction to a very low fiber diet.
  • Even if one takes supplements, we know that isolated nutrients do not act in the same way as nutrients found in whole foods.
  • Another side effect is yo-yo dieting. We don’t have long-term studies on the keto diet, and it may because it is so difficult to adhere to that people aren’t staying on it for a long period of time. If trying to go keto causes you to “yo-yo” and go on and off diets, this has impacts related to weight fluctuations and increased mortality risk.

Check out the other nutrition questions I’m answering at The Plant-Powered Dietitian:

Is Coconut Oil Healthy?
Do Turmeric and Hemp Prevent Cancer?
How Can I Make the Switch to a Vegan Lifestyle?

About Ask Sharon

As part of my program “Ask Sharon”, I am answering the top question of the month submitted through my   blogFacebook,     Twitter   or   Instagram   to answer here. You can even win a prize! Don’t forget to submit your burning nutrition question this month via my blog, or other social media. Here is my favorite question this month.

Image: produce at a local farmers market, Sharon Palmer, RDN

5 thoughts on “Should I Try a Keto Diet?

    • Yes, thank you for pointing out the health benefits of spices. I am a big fan of increasing spices, such as cumin, turmeric, ginger, and garlic in the diet to reduce inflammation. Read more about it here.

  1. Why do so many people on the keto diet seemingly reverse health issues, claim they’re sleeping better, and also claim they’ve never felt better in their whole lives (even long-term keto followers)?

    • These are anecdotal reports, not science-based evidence. However, I think it’s important to listen to one’s individual reactions to lifestyle habits. But as a nutrition expert I just can’t get around the fact that people eliminate foods that we absolutely know are important for human health. The long term effects of this diet really concern me.

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