Following a ketogenic diet involves minimizing carbohydrate intake and increasing fat consumption to create a fat-burning process called ketosis.
If you’re going to successfully achieve this process, knowing what not to eat on Keto is every bit as important as knowing which foods you can safely put on your plate.
As you’ll see in this guide, some foods can derail your weight loss progress by booting you out of ketosis.
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Which Foods Should You Avoid on a Keto Diet?
Below, we’ll look at each of these main food types, explaining why they should be left out of your meals and providing specific examples of what you shouldn’t eat on a Keto diet.
1. Foods With a High Sugar Content
If you have something of a sweet tooth, you may not be too happy to learn that cookies, candies, chocolate, cakes, and soda are among the first things you’ll be saying goodbye to on the Keto diet.
If you have previously read our guide to ketosis, you’ll recall that the ketosis state occurs when the body can’t create energy-giving glucose from the sugars in carbohydrates.
Hence, if you’re naturally eating foods with a lot of sugar in them, you’re preventing ketosis from occurring, and the diet isn’t going to work for you.
It’s worth remembering that carbs only account for 10% of your daily calorie intake on the Keto diet. On a 2,000-calorie diet, that’s 25 grams.
A standard can of Coca-Cola measuring 375ml has 39.8 grams of carbohydrates, almost 15 grams more than you should consume.
2. Starch-Heavy Foods
Like sugars, starches are converted into glucose to give the body energy.
So when you eat a lot of starchy foods, the body can produce enough glucose. As such, it doesn’t need to produce ketones and thus won’t get into a state of ketosis, ultimately meaning you’re unlikely to achieve the weight loss goals you set.
With all this in mind, starch-heavy carbohydrate sources like bread, potatoes, rice, pasta, and grains should be avoided on the Keto diet.
If this just about eliminates all of your favorite dishes, healthy alternatives are always available. For example, rice can be replaced with cauliflower rice, while your favorite pasta dishes can be made with zucchini noodles.
3. Certain Fruits
At first glance, fruit might seem like an odd food to avoid on any diet.
After all, isn’t fruit supposed to be good for us?
In some cases, yes, they are. However, fructose-rich fruits like bananas, apples, grapes, mangos, and peaches are all high in carbohydrates. This means an average-sized piece of fruit would take up all your daily carb allowances, if not wholly exceed them.
For example, a medium-sized apple and a single cup of mango each contain about 25 grams of carbs, while a banana has 27 grams.
Raisins, pineapple, pears, and dates are other carb-heavy fruits its best to steer clear of.
4. Root Vegetables
There’s a common mantra in the Keto community:
“If it grows above ground, go for it. If it grows underground, avoid it.”
What we mean by this is that most vegetables that grow above the soil (such as tomatoes, spinach, lettuce, mushrooms, and cucumber, to name but a few) are all A-OK to add to any Keto-friendly meal as they contain very few carbohydrates.
However, foods that grow beneath the soil, particularly potatoes and other root vegetables like parsnips, carrots, onions, and garlic, are all high in carbs.
To give you some idea of how much carb content we’re talking about, there are 26 grams of carbohydrates in a single white potato, 27 grams in a sweet potato, and 24 grams in one cup of diced parsnip.
Other vegetables that should be avoided on a Keto diet include yams, peas, and sweetcorn, as these also contain high amounts of carbohydrates.
You can safely replace them with any of the options in our guide to the 20 best Keto-friendly vegetables.
5. Beans and Legumes
Beans and legumes may be tiny, but add just a cup of them to your meal, and those carbs soon pile up.
Lentils, chickpeas, kidney beans, black beans, lima beans, and soybeans all contain more than enough carbs to prevent ketosis should you eat more than a handful.
A half-cup serving of chickpeas alone has 25 grams of carbs, more than the daily allowance on stricter ketogenic diets limited to 10% carbs. Meanwhile, the same-sized portion of kidney beans has 20 grams, and a half-cup of lentils has 18 grams.
To put this another way, if you add beans and legumes to your diet, you will only be able to consume a very small quantity to ensure you stay in ketosis.
6. Processed Foods
It shouldn’t come as a surprise to find that processed foods like fries, burgers, potato chips, and breakfast cereals are all more or less outlawed on the Keto diet.
Even if you’re not on a low-carb diet, these foods are usually best consumed in moderation as they contain a ton of added sugars and unhealthy fats, which can wreak havoc on our physical health.
Since such foods generally lack many basic essential nutrients, they can be responsible for causing dramatic sugar spikes and crushing sugar crashes, affecting our well-being and hindering ketosis.
Along with all of the processed foods listed above, convenient favorites like frozen dinners, crackers, cheese spreads, and processed meats such as hot dogs and sausages all contain enormously high volumes of carbohydrates, which -as we all know by now- is the last thing you want on a low-carb diet.
Drinking too much alcohol is never a good idea, to begin with, but if you’re trying to lose weight on the Keto diet, you’ll find that all those added carbs and sugars in your favorite beers, wines, and pre-mixed drinks may kick you out of ketosis and away from your goal.
Fortunately, there is some good news for Keto followers who enjoy the occasional tipple or two. Dry keto wine is usually OK in moderation.
Spirits and sugar-free mixers, like a good old-fashioned gin and tonic or vodka and soda, have fewer carbohydrates to keep them on your Keto cocktail menu for those special occasions. Here are some other keto cocktail ideas.
That said, it’s still worth keeping in mind that alcohol can lower our inhibitions, and that may make it more difficult to make smart, Keto-conscious choices should those post-drink munchies kick in.
What Foods Should You Not Eat on Keto Diet: Summing Up
On the whole, there are a lot of foods you need to avoid on the Keto diet.
Fruits, root vegetables, beans, legumes, processed foods, and anything with high sugar or starch content are best left off your plate while trying to shed the pounds if you want to maintain a state of ketosis long enough to achieve significant weight loss.
While that may seem like there’s a lot you have to cut out, there are still many tasty and healthy foods you can enjoy.
See our guide titled What Can You Eat on the Keto Diet? to find out what they are.
Finally, it’s important to remember that while a ketogenic diet can be an extremely effective way to lose weight, it’s essential to follow the process of responsibility and talk with a healthcare professional to ensure it’s right for you.
In the meantime, you can learn more about the Keto diet in this complete beginner’s guide.