James McCarter presenting the results of his one-man, one-year experiment at the 2015 Quantified Self Conference. Vimeo For a whole year, geneticist Jim McCarter went on a super-low-carb, high-fat diet to see what would happen.

He gave up sugar and high-carb foods and got 80% of his calories from fat. McCarter presented what he learned at the 2015 Quantified Self Conference.

Low-carb diets (think Atkins) have been one of the most common ways to treat obesity since the 1960s.

McCarter's method, called a ketogenic diet, or keto for short, is a diet extremely low in carbohydrates (often less than 20 grams a day) that is most commonly recommended by doctors to treat epilepsy in children. It's also typically high in fat in and low in protein.

According to the Mayo Clinic, side effects can include "nausea, headache, mental and physical fatigue, and bad breath." In children on the diet long term, more serious side effects, like kidney stones and brittle bones, have been observed.

For dieters, the idea is that reducing carbohydrate intake so dramatically will force the body to burn stored fat, a state called ketosis. This kind of eating plan has been shown in some scientific studies to control hunger and lead to weight loss.

In his Quantified Self talk, which we first saw on BoingBoing, McCarter said he saw similar results: He got hungry less easily, lost 25 pounds, and shed half his body fat.

He also reported better concentration, better stamina, and better cholesterol. (Bear in mind that these are the self-reported effects from a single person; large studies would be needed to test whether some of the effects McCarter saw are the norm.)

For a while though, McCarter said it took him longer to warm up for a workout. He also frequently had muscle cramps, and he got cold more easily. But he said getting about 5 grams of sodium a day had prevented these issues.

That level of salt is above the recommended upper limit of 2.3 grams, and he referred to a 2014 study finding that 4 to 6 grams of sodium a day could increase cardiovascular risk. But that's not putting McCarter off his ketogenic diet.

"I've learned that the benefits of ketosis, for me, are substantial, and they make me want to continue," McCarter said at the conclusion of the talk. "Getting rid of sugar was the easy part — more challenging has been moderating protein and getting enough fat and salt. And that requires contradicting conventional wisdom about nutrition."

A scientific review published this November concluded that ketogenic diets were more effective for weight loss than low-fat diets were, supporting previous studies suggesting this was the case.

But the Mayo Clinic advises caution: "It's not clear what kind of possible long-term health risks a low-carb diet may pose because most research studies have lasted less than a year."

How long people stay on a diet can matter much more than the type, since keeping weight off can be harder than losing it. That's one reason extreme diets, like some version of the ketogenic diet, don't work for many people.

Most important, your overall health should take priority over simply your weight. The ketogenic diet may well be a good bet for some people, but consult your doctor or a licensed dietician before dramatically changing your eating habits.

Watch McCarter's full talk here:

The Effects of a Year in Ketosis by James McCarter from Quantified Self on Vimeo.