Paleo, Mediterranean, intermittent fasting, low carb… if we had a wheatgrass shot for every diet claiming to be the best, we wouldn't need a diet at all.
The truth is, there’s no one size fits all diet. And no matter what your goals are—weight loss, better health, more energy—the best diet for you is the one you can actually stick with.
That's why it's important to have all the facts before you dive in.
If the ketogenic diet (“keto” for short) has caught your attention and you’re considering giving it a go, you'll want all the details before you begin—what it is, how it works, what the science says, and what to eat.
Here’s everything you need to know about the keto diet:
What is the Ketogenic Diet?
Keto is a very low carb, high fat diet designed to force your body to use stored fat instead of blood sugar as its primary source of energy—a process called ketosis.
Unlike other low carb diet plans, a true keto diet is extremely high in fat and only moderate in protein content. That's because eating too much protein can prevent the body from using stored fat for energy. While there is no set ratio of macronutrients (carbohydrates, fats and protein) that defines the keto diet, most proponents recommend getting 70 to 80 percent of total calories from fat, five to 10 percent from carbohydrates, and 10 to 20 percent from protein. This differs greatly from the Institutes of Medicine's acceptable macronutrient distribution range (AMDR), which is the range of nutrient intake associated with reduced risk of chronic disease while providing intakes of essential nutrients. The AMDR for fat is 20 to 35 percent, carbohydrates is 45 to 65 percent, and protein is 10 to 35 percent.
For most people, following the keto diet means eating fewer than 50 grams of carbohydrates per day. For reference, a medium banana has about 28 grams of carbs.
How Does it Work?
Your body's preferred source of energy is glucose, which is a product of carbohydrate metabolism. A keto diet severely restricts carbohydrate intake to the point that there isn't enough glucose available, and your body has to find alternative sources of fuel.
In the absence of blood sugar, your body will start breaking down stored fat into molecules called ketones, which your cells use to generate energy until glucose becomes available again. This process is called ketosis.
How much you’d need to restrict your carbohydrate intake in order to enter ketosis depends on a number factors and is highly personalized. But generally speaking, eating between 20 to 50 grams of carbohydrates per day for two to four days should do the trick.
What Do You Eat on Keto?
Anyone who's ever tried counting carbs before knows how hard it can be to restrict them. That's because they're not just in obvious sources like pasta, bread and pizza. Carbs are found in unsuspecting sources like fruit, starchy veggies, beans, even dairy products. That's why many people find a keto diet tricky to navigate—and sustain long-term. Staple foods on the keto diet include high fat and high protein foods like meat, eggs, cheese, eggs, fish, nuts, butter, seeds, oil and high-fiber, low carb veggies.
Given the popularity of this diet, many brands have created ready-to-eat meals and snacks that are keto-compliant. Zing has a full line of keto-friendly, plant-based protein bars featuring creamy nut butter bases, cocoa butter, medium chain triglycerides (MCTs), and sea salt and spices, which are aligned with the macronutrient recommendations for a keto diet. They’re delicious and contain no added sugars or artificial flavors. And they only have fewer than three grams of net carbs per serving, making them a no-brainer for those following a keto diet.
What the Science Says
Research on the keto diet is still evolving and those studies that do exist have had limitations like small participant pools, no control groups, and short durations. Here’s what we know so far about keto:
Keto and Health
While scientists and medical professionals are exploring the impact of the keto diet on a variety of health conditions and diseases, including cancer, polycystic ovary syndrome (PCOS), multiple sclerosis, sleep disorders, autism, Parkinson’s and Alzheimer’s, at this point in time, the findings are inconclusive.
There is some evidence that the keto diet can help improve blood sugar control in people with type 2 diabetes—at least for the short-term. Some very preliminary findings also suggest that keto may have a positive impact on cholesterol. However, the lack of long-term research on both blood sugar and cholesterol prevents many experts from drawing any definitive conclusions about the connection.
There is one thing we do know for sure about the keto diet: It can be an effective treatment for epilepsy in children who do not respond to standard medications. There is substantial research suggesting that this diet can reduce seizures in children.
Keto and Weight Loss
In recent years, as low carb diets like Atkins, Paleo and South Beach have grown in popularity, keto has emerged as a possible weight loss solution as well.
So what does the research say about the effectiveness of the keto diet for weight loss? Basically, that following a keto diet may result in faster, but not necessarily more, weight loss than conventional weight loss diets.
That’s right: Studies suggest that a keto or very low carb diet may result in faster weight loss than traditional low-fat diets and the Mediterranean diet. However, research also suggests that that difference in weight loss seems to disappear over time.
Given the restrictive nature of the keto diet, some experts contend that those trying to shed extra weight may find more success on a conventional, calorie controlled diet.
For many people, making the switch to keto comes with some unpleasant side effects collectively referred to as the "keto flu.” As your body adjusts to the extreme carbohydrate restriction, you may experience some or all of the following symptoms: Hunger, irritability, fatigue, nausea, vomiting, constipation, sleep problems, bad breath and even "brain fog."
But that’s not the only downside to this diet. Some experts caution that those who follow keto long-term put themselves at an increased risk of kidney stones and osteoporosis, as well as increased blood levels of uric acid, a risk factor for gout.
Yet another concern? Possible nutrient deficiencies. Due to the lack of food variety on the keto diet, it’s very easy to miss out on important nutrients like fiber, B vitamins, and minerals like iron, magnesium and zinc. That’s why consuming a variety of keto-friendly meats, fish, vegetables, fruits, nuts and seeds is so vital—its the best way to ensure adequate intake of nutrients the body needs to perform.
A keto diet has some decided health benefits for very specific populations, and is being studied for its potential benefits for other groups as well.
Those pursuing quick weight loss results may achieve them with the keto diet although it's highly restrictive nature may make navigating and sustaining the diet difficult for some.
If you do opt to try the keto diet, make sure you are eating a wide variety of permitted foods to ensure you're meeting all your nutrition needs.