Before you go keto, know this…
The fine print on the risks and benefits of America’s latest low-carb craze.
Within the span of one week, I had two people that they had now adopted the keto diet. The first person, a friend from residency, told me she had hopped on the keto diet. “All I eat are eggs,” she said to me. Less than 48 hours later, my cousin told me the same thing: she too had adopted the keto diet. I now had two people in my life who’ve subscribed to this latest variation in anti-carbohydrate mantras– both in passing and not knowing my personal doubts on the diet. The difference in these two people compared to anyone else who’s told me that he or she has adopted has adopted the keto diet is that both were physicians: the former a budding internist and the latter a practicing rheumatologist.
These experiences serve to highlight how the keto diet straddles the increasingly blurred lines between faddist snake oil and sanctified medical therapy — so much so that physicians have now adopted it. I should not have been totally surprised as the keto diet was recently highlighted in the Journal of the American Medical Association for its ability to help people lose weight and treat diabetes, thereby christening the diet as something more than a low-carb craze. However, the science and the diet have not reached a holier-than- thou status for several important reasons, the foremost of which is the diet may simply be a biochemical ruse of societal proportions.
Nearly a century ago, prior to the discovery of insulin by Frederick Banting and Charles Best, the keto, or ketogenic, diet was used as a crude way to stave off high blood sugar levels, which was then inevitably fatal. By foregoing carbohydrates, the body utilizes fat, either stored or consumed, as it main energy source without raising blood sugar levels. In the process, ketones are produced, and thus giving the diet its name. The conundrum lies in this: If the blood sugar levels of a diabetic don’t increase, is one still a diabetic? Well, it depends on how you define it.
Imagine this: If one has credit card debt, a simple way to eliminate the debt would be to cut up the credit cards and pay down the debt until one is financially solvent. Overall, one may not be any richer by doing this but they certainly would have less credit card debt, which is undeniably helpful. In this example, having a credit card allowed one to spend beyond their means — and to continue doing so — to the point of incurring consequences. The keto diet prevents diabetics from eating “beyond their means” — by restricting carbohydrates — and from suffering the consequences of doing so. However, if given a dose of carbohydrates, their blood sugars would rise back up again. With a sleight of hand, diabetic keto dieters have found a way to lower their blood sugars, which is certainly worthy of applause as high blood sugar levels over time can cause a myriad of complications, including infections, amputations, blindness, kidney failure, heart disease, nerve pain, and, mercilessly, death.
But does the keto diet truly reverse diabetes? If the sign of wealth is the ability to afford a large purchase, then isn’t the sign of glycemic health the ability to tolerate, for example, a carbohydrate-rich hoagie without an explosive spike in blood sugar? Even experts disagree. According to the American Diabetes Association, there are four main ways to diagnose diabetes: three rely on blood sugar levels in the absence of a carbohydrate load and the fourth does. The question of whether someone has diabetes or not while on the keto diet may be moot if they’ve now mitigated their risk of the dreaded complications of diabetes. The question is even less relevant for those losing weight, which is an established therapy for diabetes.
Weight loss on the keto diet is less mystical than its powers to reduce blood sugar levels: It’s the product of devoted caloric restriction. During the zeitgeist of the last low-carbohydrate craze, which encompassed the Zone, South Beach, Atkins, Paleo, and Dukan diets, researchers found that, “In all cases, individuals on high-fat, low-carbohydrate diets lose weight because they consume fewer calories.” Many of the studies done regarding weight loss on the keto diet, including several mentioned in the JAMA article, conspicuously fail to mention daily calorie intake, raising the diets panacea-like allure. However, a closer look shows that these diets are not much better than a low-fat diet. An oft-cited meta-analysis comparing low-carb ketogenic diets to low-fat diets showed a difference in weight-loss of less than a kilogram after twelve months — a neglible difference. Interestingly enough, another, more-recent, meta-analysis showed no difference in results between low-carb and high-carb diets on weight — or blood sugar levels — after one year. So, if dietary strategy is inconsequential as long as one is dieting, why is the keto diet so popular?
One part may be diet’s apparent, yet not novel, success with diabetes, which has been a notoriously difficult disease to treat. Another is the originality of the diet, which sets itself apart from the succession of prior low-carb diets by causing its followers to make ketones. The ketones are not trivial: Since they are osmotically active, they can induce a diuretic-like response, causing dieters to lose fluid-related weight, especially during the beginning of the diet. Those early results can serve to positively reinforce dieters and may be crucial in deciding whether to continue dieting, particularly in the face of restrictive dietary options and the malaise associated with the transition, dubbed “the keto flu,” which includes a combination of gastrointestinal distress (especially constipation given the lack of fiber), cramps, dizziness, brain fog, mood disturbances, and/or insomnia.
Another important part of the diet success is the recent fanfare it has received from authoritative physicians in the field, like Dr. David Ludwig, professor of pediatrics and nutrition at Harvard Medical School and Harvard T.H. Chan School of Public Health, and Dr. Stephen Phinney, emeritus professor of medicine at the University of California,Davis, and co-founder of Virta Health, a telemedicine-based clinic treating type 2 diabetes with ketogenic diets. Virta Health’s ability to raise $45 million in investments is a telltale sign of the growing interest in ketosis.
Yet, neither my physician friend or cousin were obese or diabetic. Proponents of the keto diet will argue that it can be used for minor — and major — weight loss. However, is it safe? Does the risk of taking on a new diet with safety concerns justify the loss of a few or more pounds? It might if you are so obese or diabetic that you suffer from complications of those diseases, as almost anything will be better than suffering a heart attack or an amputation from diabetes. But perhaps not if you don’t have those comorbidities.
One of my concerns is the unnaturally high amount of fat consumed to maintain ketosis. If the diet had another name, it would be called “the fat diet” as 70–80% of calories per day come from fat. The only native population eating this much fat were the Inuit, who were forced to subsist on blubber out of necessity. And perhaps because of the high amounts of saturated and trans fats consumed, the Inuit experienced — despite popular misconceptions — a higher rate of heart disease, strokes, and death compared to non-Inuit and Western populations. The opportunity cost of not eating fruits, vegetables, and complex carbohydrates may have also contributed to their heightened risk.
Currently, there are no long-term data on the safety of the keto diet in adults. The keto diet may not be worth pursuing, even for diabetics or the obese, if we are mortgaging those diseases for higher rates of heart disease or colon cancer, a possibility given the low amounts of fiber consumed on these diets. More, we already know that the diet has not been without consequence for pediatric patients treated with it for refractory epilepsy, which has been ongoing since the 1920s. From this population, children have developed kidney stones, acidosis, fractures, and stunted growth. At the more serious end of the spectrum, children on the diet have died from arrythmias arising from selenium deficiency and pancreatitis. The possibility of these side effects and possibly others yet to be discovered may tilt the diet out of favor.
However, deliberation over the keto diet or other low-carb diets is often omitted for the purposes of a near-Machiavellian attainment of weight loss or some other health goal. Before embarking on a diet with known adverse effects in children, uncertain long-term safety in adults, and equivocal benefits when compared to other dietary strategies, both patients and physicians alike would behoove themselves to remember that diabetes and obesity are not a product of ketone deficiency but the symptom of caloric excess, dietary indiscretion, and torpor. Let food be thy medicine — but not if it involves a Faustian bargain of your health.
Shivam Joshi, MD, is a plant-based physician and nephrology fellow in Philadelphia. Follow him on Twitter @sjoshiMD.
