Ketogenic Diet: The Worst Foods You Can Eat

woman eating potato chips

Young woman eating potato chips | RossHelen/ iStock /Getty Images Plus

If you’re following the ketogenic diet, you’re likely trying to figure out what you should and shouldn’t eat. The Cheat Sheet spoke with leading health experts to get their take on the foods you should stay away from. Here are the worst foods to eat if you’re on the ketogenic diet.

Sugary and starchy foods

Consuming foods with sugar and carbohydrates (other than non-starchy veggies which have a minimal amount of carbs) will prevent you from entering the metabolic state of ketosis or remaining there. It’s also important to not overeat protein, since some protein can be converted into glucose after you eat it. In simplest terms, you need to get 70% to 80% of your daily calories from fat, no more than 20% to 25% of calories from protein, and no more than 5% to 10% of daily calories from carbohydrates (mostly veggies).

I also recommend consuming high-quality proteins and fats but limiting inflammatory foods such as processed meats like cold cuts, bacon, hot dogs, salami, poor quality dairy products, and refined vegetable oils (sunflower, safflower, corn oil, etc.).

Dr. Josh Axe, founder of Ancient Nutrition and


Cheese is highly inflammatory and although some people can tolerate it in their diet, many keto-ers replace carbs with cheese. So, you ended up eating five to seven times the amount of cheese you would normally eat. A typical keto meal might be faux bread (made from cheese) plus burger and cheese topping and then a side of Cheese Whisps instead of chips. This leads to a mucus reaction in the gut (and sometimes other areas of the body), long-term contributing to gut dysbiosis [microbial imbalance].

Audrey Christie, MSN, RN, CCMA, Holistic Wellness Practitioner


Some of the worst foods to eat on the keto diet are actually some of the best for you foods like grains, fruits, vegetables, and lean proteins like fish. The keto diet eschews carbohydrate-rich foods in favor of high-fat ones. Most people take this to mean beef, butter, and cheese. These foods are high in saturated fats and are unhealthy for the heart (not to mention everything else) and make you feel sluggish. Keto claims that if you exclusively eat a high-fat diet, then your body will start burning fat as its fuel source instead of carbohydrates (which it typically prefers) and you will be able to lose weight and body fat quickly. Unfortunately, it’s almost impossible to sustain for more than a few days and generally unhealthy in the long run overall.

You are better off eating a more balanced meal with a similar amount of calories because that will keep you full longer and you will be able to keep up that habit for the rest of your life versus doing something more extreme like keto.

Lyuda Bouzinova, co-founder of Mission Lean, and ACE certified fitness nutrition specialist and personal trainer

Processed food

The worst foods to eat on a ketogenic diet are cheap, processed food-like products such as low-quality fast-food meals, commercially produced mayonnaise full of vegetable oil and preservatives, and “sugar-free” ice cream sweetened with more artificial sweeteners and flavorings than you know how to pronounce.

Cutting out processed and refined carbohydrates is a great step toward health. To truly optimize your health, you must cut out all the junk. Even though the macros may be keto, you must be aware of the ingredients also. Filling up on processed deli meats, McDonald’s burgers, and cheap Kraft singles is not going to maximize the results you are looking for with a ketogenic diet.

Jessica Haggard, author and health coach, Primal Edge Health

Artificial sweeteners

Artificial sweeteners are extremely damaging to your gut and other organ systems. Also, they aren’t helping you to reduce sugar cravings because your body often has the same chemical reaction to these as natural sugar.

Audrey Christie, MSN, RN, CCMA, Holistic Wellness Practitioner

Saturated fats

Excessive amounts of saturated fats have been linked to chronic disease including obesity, heart disease, and certain cancers. Some examples of saturated fats are high-fat meats, processed meats, high-fat dairy, sour cream, butter, lard, and cream cheese. When I have clients tell me they’re eating bacon and sour cream at every meal, we talk about healthier fat alternatives.

Haley Hughes MS, Registered Dietitian and Certified Diabetes Educator

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