People use a ketogenic diet most often to lose weight, but it can help manage certain medical conditions, like epilepsy, too. It also may help people with heart disease, certain brain diseases, and even acne, but there needs to be more research in those areas. Talk with your doctor first to find out if it’s safe for you to try a ketogenic diet, especially if you have type 1 diabetes.
Most carbs you consume are broken down into sugar that enters the bloodstream. When you rein in carbohydrates on the keto diet, you have lower levels of blood glucose (high blood glucose can lead to diabetes). A study in the journal Nutrition reveals that a ketogenic diet improves blood glucose levels in type 2 diabetics more significantly than a low-calorie diet and can also decrease the dosage of your diabetes meds.
You can have a completely smooth transition into ketosis, or…not. While your body is adapting to using ketones as your new fuel source, you may experience a range of uncomfortable short-term symptoms. These symptoms are referred to as “the keto flu.” Low-sodium levels are often to blame for symptoms keto flu, since the kidneys secrete more sodium when you’re in ketosis, says Volek. A few side effects:
There are three instances where there’s research to back up a ketogenic diet, including to help control type 2 diabetes, as part of epilepsy treatment, or for weight loss, says Mattinson. “In terms of diabetes, there is some promising research showing that the ketogenic diet may improve glycemic control. It may cause a reduction in A1C — a key test for diabetes that measures a person’s average blood sugar control over two to three months — something that may help you reduce medication use,” she says.

When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet -- or going back to a normal diet afterward -- can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.


Advocates for the diet recommend that it be seriously considered after two medications have failed, as the chance of other drugs succeeding is only 10%.[9][31][32] The diet can be considered earlier for some epilepsy and genetic syndromes where it has shown particular usefulness. These include Dravet syndrome, infantile spasms, myoclonic-astatic epilepsy, and tuberous sclerosis complex.[9][33]
You’ll quickly find that eggs are a staple for breakfast in low carb diets. Eggies are a simple solution for days of healthy breakfasts. Simply beat 8 eggs in a bowl, add in cheese and vegetables, and pour into muffin tins that have been lined with a strip of bacon. Cook at 350 for 30 minutes, or until a toothpick stuck in the middle comes out clean. Store in baggies for breakfast for up to 5 days.

A study with an intent-to-treat prospective design was published in 1998 by a team from the Johns Hopkins Hospital[20] and followed-up by a report published in 2001.[21] As with most studies of the ketogenic diet, no control group (patients who did not receive the treatment) was used. The study enrolled 150 children. After three months, 83% of them were still on the diet, 26% had experienced a good reduction in seizures, 31% had had an excellent reduction, and 3% were seizure-free.[Note 7] At 12 months, 55% were still on the diet, 23% had a good response, 20% had an excellent response, and 7% were seizure-free. Those who had discontinued the diet by this stage did so because it was ineffective, too restrictive, or due to illness, and most of those who remained were benefiting from it. The percentage of those still on the diet at two, three, and four years was 39%, 20%, and 12%, respectively. During this period, the most common reason for discontinuing the diet was because the children had become seizure-free or significantly better. At four years, 16% of the original 150 children had a good reduction in seizure frequency, 14% had an excellent reduction, and 13% were seizure-free, though these figures include many who were no longer on the diet. Those remaining on the diet after this duration were typically not seizure-free, but had had an excellent response.[21][22]

Although you'll be cutting way back on carbohydrates and sugar, some fruits are still okay to eat on the keto diet (though you'll still want to be mindful about quantity in order to remain in ketosis). The fruits that make the cut contain far fewer carbs than their off-limits cousins such as apples, pears, bananas, pineapples, papayas, grapes, and fruit juices in general.
Tip: Consuming a moderate dose of exogenous ketones during the initial “keto-adaptation” period could potentially accelerate the “adaptation,” while at a minimum increasing energy production. Once one is adapted, these products are excellent for achieving higher blood-ketone levels, which, in turn, can be beneficial for athletic and cognitive performance, energy production, and perhaps more effective therapeutic treatment.

Cognitive Enhancement: Ketones may be the preferred fuel source for the brain. Due to the brain’s preference to uptake and utilize ketones as fuel it is very common for individuals to report an increase in cognitive performance. This is even more common in individuals with some degree of insulin resistance, as their brain is likely unable to effectively utilize glucose as a sole fuel source due to the resistance.
Fasting ketosis: Fasting ketosis, also referred to as starvation ketosis, played a major role in the development of the keto diet for beginners. The concept of fasting has been around for centuries and can be traced back to biblical times. By definition, fasting is the absence of caloric consumption for a period of time. This can range from several hours to several days and can have profound effects on the degree of ketosis. As the duration of the fasting increases, so does the production of ketones, and thus a deeper ketogenic state is obtained. As such, the mechanisms of ketone production are similar between fasting and dietary applications similar to keto diet for beginners, both of which result in lower and more stable levels of insulin and blood glucose accompanied by fat metabolism.
You may also have to moderate protein intake somewhat, as high protein intake (greater than 2.0g/kg/d) may make it more difficult to maintain ketosis. However, eating too little protein may also present health issues such as poor muscle development, increased hunger, and lack of essential amino acids. That is why we recommend a moderate level of protein intake, defined as 1.2-1.7g/kg/d. See our protein guide.

In many developing countries, the ketogenic diet is expensive because dairy fats and meat are more expensive than grain, fruit and vegetables. The modified Atkins diet has been proposed as a lower-cost alternative for those countries; the slightly more expensive food bill can be offset by a reduction in pharmaceutical costs if the diet is successful. The modified Atkins diet is less complex to explain and prepare and requires less support from a dietitian.[55]
Insulin is a hormone that lets your body use or store sugar as fuel. Ketogenic diets make you burn through this fuel quickly, so you don’t need to store it. This means your body needs -- and makes -- less insulin. Those lower levels may help protect you against some kinds of cancer or even slow the growth of cancer cells. More research is needed on this, though.
In terms of weight loss, you may be interested in trying the ketogenic diet because you’ve heard that it can make a big impact right away. And that’s true. “Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. She explains that your body will first use up all of its glycogen stores (the storage form of carbohydrate). With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down (often dramatically), do keep in mind that most of this is water loss initially. 
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