A “typical” ketogenic diet consists of at least 70 percent of calories derived from fat, less than 10 percent from carbs and less than 20 percent from protein.
The ketogenic diet, long used to treat epilepsy in children, calls for 90 percent of daily calories to come from fat, with the amount of protein or carbs varying as long as it’s 4 grams of fat for every combined 1 gram of carb and protein, according to the American Epilepsy Society.
That can mean chowing down on a lot of cheese, butter, eggs, nuts, salmon, bacon, olive oil and non-starchy vegetables such as broccoli, cauliflower, greens and spinach.
For the arithmetic-challenged, apps and online programs can do the math for you. (No matter what, the keto diet is vastly different than the USDA dietary recommendations of 45 to 65 percent of one’s total calories to be carbohydrates, 20 to 35 percent from fat and 10 to 35 percent from protein.)
The goal of the ketogenic diet is to enter a state of ketosis through fat metabolism.
In a ketogenic state, the body uses primarily fat for energy instead of carbohydrates; with low levels of carbohydrate, fats can be converted into ketones to fuel the body.
For ketosis, a typical adult must stay below 20 to 50 grams of net carbohydrates — measured as total carbs minus fiber — each day.
Crossing that threshold is easy: a thick slice of bread adds 21 carbohydrates, a medium apple 25 and a cup of milk 12. “It’s very restrictive,” said Carla Prado, an associate professor and director of the University of Alberta’s Human Nutrition Research Unit.
It’s not just bread and soda that are on the outs but high-sugar fruit and starchy veggies like potatoes, as well as too much protein.
Also, dieters have to be on high alert for hidden carbs, often invisible to the eye, yet coating that seemingly keto-friendly fried cheese.
How The Keto Diet Works
The ketogenic diet is a high fat, moderate protein, low carbohydrate eating pattern, which differs from general, healthful eating recommendations.
Many nutrient-rich foods are sources of carbohydrates, including fruits, vegetables, whole grains, milk and yogurt. On a keto diet, carbs from all sources are severely restricted.
With the goal of keeping carbs below 50 grams per day, keto dieters often consume no breads, grains or cereals.
And, even fruits and vegetables are limited because they, too, contain carbs. For most people, the keto diet requires making big shifts in how they usually eat.
Why does the Keto diet restrict carbs?
Carbs are the main source of energy for our body. Without enough carbs for energy, the body breaks down fat into ketones.
The ketones then become the primary source of fuel for the body. Ketones provide energy for the heart, kidneys and other muscles.
The body also uses ketones as an alternative energy source for the brain. Hence, the name for this eating pattern.
For our bodies, a ketogenic diet is actually a partial fast. During a total fast or starvation state, the body has no source of energy.
Thus, it breaks down lean muscle mass for fuel. With the keto diet, the ketones provide an alternative source of energy. Unlike a full fast, the keto diet helps to maintain lean muscle mass.
Can I lose weight on the keto Diet?
Yes. Certainly in the short-term, it appears that way. For the first two to six months, there’s evidence that a very low-carbohydrate diet can help you lose more weight than the standard high-carbohydrate, low-fat diet, according to a new literature review of low-carb diets by the National Lipid Association.
“By 12 months, that advantage is essentially gone,” said Carol F. Kirkpatrick, director of Idaho State University’s Wellness Center, and lead author of the new literature review.
After that, weight loss seems to equalize between those two popular diet regimens. She said keto was best used to kick-start a diet, before transitioning to a carb intake that you can adhere to for the longer term.
How long does it take to see results on the keto diet?
For some, it’s the promised land of diets. Instead of cringing through carrot sticks, they can fill up guilt-free on chorizo with scrambled eggs. Indeed, some evidence suggests that people feel less hungry while in ketosis, and have fewer cravings.
“That’s why it’s become so popular for the general population,” said Dr. Mackenzie C. Cervenka, medical director of Johns Hopkins Hospital’s Adult Epilepsy Diet Center. “Because once you are in ketosis, it’s easy to follow.”
Usually, it takes between one to four days to enter the state, doctors say, but it depends on many factors like activity level: a runner, for example, may sprint there faster than a couch potato.
The keto diet appears to deliver fast results: The first pounds may seem to slip off. That can be seductive but it’s likely water weight.
Then, dietitians say, it’s back to energy in minus energy out. You can absolutely gain weight on any diet if you’re consuming 5,000 calories a day, according to Dr. Linsenmeyer, who is also director of Saint Louis University’s Didactic Program in Dietetics.
“It’s not like it is going to magically alter your metabolism to where calories don’t matter anymore,” she said. And when resuming the carbs, that water weight returns.
But can the ketogenic diet help to burn more calories?
There is some evidence that it can. The research is limited and conflicting here too. It may be a very small effect, and not meaningful for weight control. That’s what one study found.
In it, 17 obese or overweight volunteers moved into metabolic wards for two months and had every last spoonful of food monitored.
(This recounting of the science uses definitional terms like “obese” to be clear about the subjects of research studies.)
For the first month, they consumed a high-carb diet; for the second, they had a ketogenic one, with both plans equal in calories.
“We fed them every morsel of food that they ate,” said Kevin Hall, integrative physiology section chief for the National Institute of Diabetes and Digestive and Kidney Diseases’ Laboratory of Biological Modeling. “There were no cheat days.”
In the end, though the participants’ insulin levels did decrease while eating the bunless burger, the subjects didn’t lose more fat than when they had bread.
The study was limited, though, by having a small sample size, and not having a comparison group that wasn’t on the back-to-back regimens.
For some, a low-carb diet can be appealing. That doesn’t mean that diet is superior, according to a study that followed 609 overweight adults on either a low-carb or a low-fat diet for a year.
In the end, both groups shed almost the same amount on average — about 12 to 13 pounds, according to the randomized clinical trial that examined a low-carb diet less restrictive than the keto.
The take-home message? “You can succeed on both,” said Christopher Gardner, the lead author and a professor of medicine and nutrition scientist at Stanford Prevention Research Center.
If you’re still sceptical, keep in mind that ketosis is a perfectly natural state for your body and metabolism to be in.
In addition to the keto diet, the supplement GlucaFix is also said to help your body enter ketosis.
As stated by the manufacturer, GlucaFix activates the body’s glucagon, improving lipolysis and curbing inflammation, while simultaneously improving the ageing process, and the user feels more energetic and youthful. Fat is converted into ketones during lipolysis.
However, since the supplement industry is barely regulated, you might want to read some GlucaFix reviews before making any purchase.
Is there a healthy way to eat more fat?
When Dr. Cervenka of Johns Hopkins Hospital starts her patients with epilepsy on a low-carbohydrate diet, she doesn’t rule out saturated fats from animal products.
She wants them to get used to the new way of eating. But if cholesterol levels climb and stay that way, she advises them to shift to foods and oils with mono- and polyunsaturated fats like avocados or olive oil.
While the diet’s effect on LDL (“bad” cholesterol) appears to be mixed, the National Lipid Association’s review found that a very low-carbohydrate diet does seem to improve HDL (commonly known as the good cholesterol).
Beyond a year, it seems these benefits don’t last, much like in weight loss. Only lowered triglyceride levels seem to have any staying power.
Other findings: The evidence on blood pressure is inconsistent, and the reports of improved mental clarity are not supported by controlled studies.
Is the Keto Diet Safe?
This eating pattern is not recommended for individuals with:
- Pancreatic disease
- Liver conditions
- Thyroid problems
- Eating disorders or a history of eating disorders
- Gallbladder disease or those who have had their gallbladders removed
Plus, associated with the keto diet. Short term health risks include flu-like symptoms.
there are both short-term and long-term health risks for all people
For example, upset stomach, headache, fatigue and dizzy spells. This is called the “keto flu.” Some people also report trouble sleeping.
Cutting back on high-fiber vegetables, fruits and whole grains also can increase risk for constipation.
Often keto dieters must take a fiber supplement to help stay regular, but this should be discussed with a health care provider.
Long term health risks of the keto diet include kidney stones, liver disease and deficiencies of vitamins and minerals.
To limit carbs, many nutrient-rich vegetables and fruits are cut out. Thus, intakes of vitamin A, C, K and folate usually are low.
The high fat nature of the keto diet is very controversial. A considerable body of research has shown that diets high in saturated fat may increase the risk for heart disease and other chronic health problems.
The risk that keto dieters might be taking with regards to their long-term cardiovascular health has not been fully studied.
What the Science Tell Us About the Keto Diet
The keto diet has been used to help manage epilepsy, a disorder characterized by seizures, for more than 100 years. More recent studies are evaluating the keto diet as an alternative dietary treatment for obesity and diabetes.
Research findings on the benefits of the keto diet for these health conditions are extremely limited. Studies on the effectiveness of the keto diet were conducted with small groups of people. And, most of the research about Alzheimer’s disease relies on research done on lab animals.
To fully assess the safety of this eating pattern, more research is needed. Plus, studies must be done on the long-term health effects of the keto diet.
Body mass index and individual metabolic rates impact how quickly different individuals produce ketones.
This means that on the keto diet, some people lose weight more slowly than others — even if they are following the same exact keto diet plan. For this group of people, the keto diet can be frustrating and may impact their motivation for making healthy dietary changes.
Plus, many people are not able to stick with the keto diet and gain back the weight after returning to their previous pattern of eating.