Lisa Sanders of the US Special Operations Command said the diet helped military members deal with oxygen deprivation, which Navy SEALs experience while diving.

The ketogenic diet severely limits carbohydrates, relying instead on protein and fat, and evidence suggests it allows a diver to stay underwater longer.

There is an ethical dilemma in telling members of the military to follow a certain diet.

The US military has been looking at changing the diets of elite operators like Navy SEALs as new evidence emerges that their diet could enhance their abilities on the battlefield, especially underwater, but officials are concerned about what it could mean legally and in terms of their health.

The ketogenic, or keto, diet, is high in protein and fat and very low in carbohydrates. The diet forces the body to go into ketosis, in which the body burns stored fat, or ketone bodies, as energy instead of blood sugar, which comes from carbohydrates.

Research shows the ketogenic diet can help human bodies stay underwater for longer periods of time, according to The Washington Times.

That would allow elite operators like Navy SEALs to be more effective on a combat dive or a raid that starts from an underwater SEAL Delivery Vehicle.

Lisa Sanders, the director of science and technology at US Special Operations Command, touted the findings but raised ethical concerns about promoting a particular diet among soldiers.

The keto diet could help Navy SEALs be more effective during combat dives. dvids/Flickr

"One of the effects of truly being in ketosis is that it changes the way your body handles oxygen deprivation, so you can actually stay underwater at [deeper] depths for longer periods of time and not go into oxygen seizures," Sanders said at the Special Operations Forces Industry Conference (SOFIC) in Tampa, Florida, in May.

"That kind of technology is available today," Sanders said. "We can tell whether you are or are not in ketosis. We have really good indications of how to put you in ketosis. And we know statistically what that does to your ability to sustain oxygen."

Sanders told Business Insider via email that USSOCOM is currently funding "a small business research effort to assess the effect that ketosis has on altitude-induced hypoxia, as well as develop and assess alternative (non-dietary) means to achieve ketosis."

"In addition, we are tracking two additional studies funded through the Office of Naval Research assessing ketosis results in other extreme environments that are relevant to SOF warfighters," Sanders said.

Following a keto diet helps reduce what's known as the respiratory quotient, or the amount of carbon dioxide the body produces in relation to the amount of oxygen it consumes, according to Dr. David Ludwig, a nutrition professor at Harvard's T.H. Chan School of Public Health.

"It's not the oxygen in the blood that makes you want to breathe," he told Business Insider. The buildup of carbon dioxide in the bloodstream triggers the need to breathe. The ketogenic diet, he said, "is the best way to lower carbon dioxide production" and reduce the respiratory quotient.

So on a ketogenic diet, the body needs to breathe less — theoretically, as much as 30% less, according to Ludwig. In reality, though, the body would need to breathe something more like 15% less, which Ludwig said is still significant in extreme situations, like living in a submarine or diving to retrieve an explosive ordnance.

"This is one well-established metabolic fact, but we don't know the long-term health effects," Ludwig said. The keto diet's effect on things like long-term cardiovascular and neurological health hasn't been studied, he said.

Jeff Volek, a professor in the Department of Human Sciences at the Ohio State University, coauthored a small study on the effects of the keto diet on 29 people, many of them members of the campus ROTC.

About half the participants followed the keto diet. They were able to maintain ketosis for 12 weeks and lost an average of 17 pounds and 5% body weight.

"We showed that a group of people with military affiliation could accept a ketogenic diet and successfully lose weight, including visceral adipose tissue, a type of fat strongly associated with chronic disease," he told The Washington Times.

Dr. David Ludwig said the keto diet makes it so the body breathes less. US Navy

While the study doesn't indicate anything about the effectiveness of the diet on military performance, "this could be the first step toward a bigger study looking at the potential benefits of ketogenic eating in the armed forces," he said.

But Sanders cautioned that Pentagon officials faced an ethical dilemma — sacrificing personal choice and freedom for the sake of a more effective fighting force.

"For me, it smacks of the removal of free will from one of the most basic of biological functions: eating and consuming energy. It's also one that misunderstands and misrepresents how a biological organism works," E. Paul Zehr, a neuroscientist and professor at the University of Victoria in Canada, told The Washington Times.

Sanders raised the same ethical concerns at the May conference.

"Anything that deals with a human — our policies and authorities are really difficult to navigate because we have a lot of value on privacy and personal choice," she said.

Moreover, Zehr told The Washington Times, "biological beings are not automatons or machines. You can't just attempt to optimize one thing and not have it alter something else. All systems … exist in a balance."

Humans are more alike than different in terms of nutrition, Zehr told Business Insider. But "there are still many differences in terms of digestion and metabolism."

"To truly implement the most 'optimized' diet (whatever that may mean) would require extensive assessment of each soldier and then a specific diet plan for each and every one. Not a blanket 'one size eats all,'" said Zehr, the author of "Chasing Captain America: How Advances in Science, Engineering, and Biotechnology Will Produce a Superhuman."

Philosophical dilemmas and doubts about the keto diet aren't slowing scientific progress. Volek told Business Insider he hopes to perform more studies on whether the keto diet can improve troop effectiveness.

"We are motivated to perform larger and more comprehensive studies aimed at elucidating therapeutic and health/performance benefits of ketosis for military members," Volek said in an email. "We have submitted several grants over the years and continue to do so to move this from hypothesis to the lab to the battlefield."