By Sarah Jaffe, The Associated Press Ketogenic diets have become popular in the United States.
The diet has been embraced by people with conditions that cause fatigue and chronic pain, including those with diabetes, heart disease and high blood pressure.
But experts say it is risky for long-term health and that it can lead to health problems including depression and anxiety.
A ketogenic diet can also increase risk of diabetes and obesity, but experts say the risks of both can be managed.
The Food and Drug Administration has approved ketogenic diets for certain conditions such as diabetes and heart disease.
It also approved them for some people with chronic pain.
The new rule takes effect Dec. 15, but the Food and Drugs Administration will have until March 1 to set guidelines.
Some experts say keto diets may be good for people who are not at risk for serious illnesses, such as people with heart disease or stroke, or for people with diabetes who have lower blood sugar levels.
But others say the diet has become so popular, that people are making the decision without a lot of evidence.
The ketogenic approach to eating was popularized in the late 1960s and early 1970s with the work of Harvard physician Harold Bornstein and his colleagues at Harvard Medical School.
They focused on the effects of low carbohydrate diets and prescribed a diet of mostly fruit, vegetables, grains and beans.
In 1977, they published a book called “The Ketogenic Diet.”
They wrote that the diet was an excellent alternative to the standard American diet and that people who followed it were better off.
Bornstein said he used a “slow” ketogenic method of eating, and that he didn’t recommend eating more than 3,000 calories a day.
“It’s just like a little slow-cooker meal, and you can eat a little bit at a time,” Bornstein told reporters in 1977.
“I think it works pretty well.”
The keto diet is the most popular form of weight-loss, especially among older people.
Bornfield’s group recommended a diet with moderate amounts of fruits and vegetables, nuts and seeds and a diet low in meat, poultry, eggs and dairy products.
In a 1976 book, Bornstein described the keto approach as a “low carbohydrate, low fat, high protein” diet that included plenty of fruits, vegetables and other grains.
But Bornstein wrote that it was “too simple” and “unproven” and recommended a combination of a low-carbohydrate, high-fat diet and a high-protein, low-fat or no-carb diet.
The book also recommended adding fish to the diet, though it was unclear whether that would be part of a keto regimen.
The U.S. government’s Food and Nutrition Board, a group that sets nutrition standards, approved a ketogenic-based diet for people 65 years or older in 2009.
But it has since withdrawn the dietary guidelines, and it has not made it mandatory that Americans eat a ketos diet.
But the FDA has approved a diet based on keto in the past.
The agency approved the Atkins diet for a diet that is low in carbohydrate, high in protein, moderate in fat and low in saturated fat in 2009, and approved the ketogenic program in 2012.
It said it wanted to review the Atkins program before finalizing the ketones guidelines.
In 2012, the FDA also approved a new version of the ketotic diet, called the ketone diet, and the ketolone diet.
Both diets were based on a diet high in fruit and vegetables and moderate in fats and saturated fat.
But researchers who analyzed the new ketolones diet found that the ketosis was too rapid and that the effects were not as intense as those on the Atkins.
The FDA approved a lower-carb version of a lower carb diet in 2017.
The Atkins diet was not approved for people younger than 65, though a study by the U.K. government found that a low carbohydrate diet was safe for older people in a ketosis.
The American Dietetic Association recommended the Atkins as the recommended diet for older adults in 2011.
The USDA’s National Institutes of Health approved a low carb diet for the elderly in 2017, but it was not recommended for the younger population.
The federal government is not required to allow a ketone-based dietary regimen for children under age 6 because of concerns that a ketones diet may lead to a type of obesity called metabolic syndrome.
A 2016 study by researchers at Harvard University found that older adults who ate a ketotic dietary regimen had lower rates of cardiovascular disease, hypertension and diabetes.
But many experts say that children are too young to know what is best for them and that their parents should be the ones deciding what type of diet they eat.
The CDC has guidelines for children, and parents should decide for themselves, said Dr. Mark Hyman, the director of the National Center for Complementary and Alternative Medicine at Children’s Hospital Boston.
A 2013 study found that children who followed