New year, new diet?

Thursday, January 12, 2017

Imagine it’s 2012. Now, picture someone walking around a busy downtown street stopping people at random and asking them if they had ever heard of the Ketogenic diet. I would guess that fewer than 10 people would have responded in the affirmative, even though the diet has been used since the early 1900s to treat epilepsy. Fast forward to 2017 and I am willing to bet that 25 or more would know something about the Ketogenic diet. Why this sudden jump in popularity?

Part of this can be attributed to athlete and celebrity endorsements. A handful of world record-setting endurance athletes swear by the Ketogenic diet and insist that it played a large role in their athletic achievements. What’s so special about this eating pattern? Typical American diets consist of about 60 percent of one’s daily energy (i.e., calories) coming from carbohydrates, about 15 percent from protein, and about 25 percent from fat. Contrast this with the Ketogenic diet which requires 10 percent of one’s daily calories from carbohydrate, 20 percent from protein, and a whopping 70 percent from fat. Essentially, it’s a lower carbohydrate, high-fat diet. Is it possible that following such an extreme diet could be beneficial?

Based on observational case studies performed in the 1920s, explorers observed Inuit populations consuming large amounts of dietary fat. At the same time, they did not appear to suffer from the chronic diseases commonly seen in Western societies. Since then, studies have been performed to test the effects of the Ketogenic diet. The majority of these studies have recruited elite athletes as participants. Results showed that, during activity, these athletes burned more fat as fuel and were able to improve their endurance.

We know that in the short term, when otherwise healthy individuals follow this eating style, it appears to be relatively safe. But, when switching from a standard American diet, which consists mostly of carbohydrates, to one of mostly fat there will be some side effects. Individuals often complain of feeling fatigued (which could be the result of having low blood sugar due to the decreased intake of carbohydrate), may experience constipation (also due to the reduced carbohydrate intake) or diarrhea (because of the increased fat intake), may develop gallstones and possibly experience vitamin deficiencies.

It should also be noted that because many of the more recent studies examining the health effects of the Ketogenic diet used elite athletes as participants, this is a unique subset of individuals. Elite athletes have very different nutritional needs when compared to those of us that do not possess these superhuman-like abilities. Also, as mentioned above, the majority of the studies were performed over the short term (<six months). I recently attended an academic conference and happened to speak with one of the leading Ketogenic diet researchers Marlia Braun, PhD, RDN and asked, “We have all of this data on the short-term effects of following a Ketogenic diet, but what happens when otherwise healthy individuals follow this diet for a year or more?” Her response, “We don’t know.” So, it is possible that over the long term, individuals may not experience these same benefits. Plus, this diet is very strict. I am not so sure that long-term adherence is realistic.

If this type of eating pattern appeals to you, it would be wise to discuss the Ketogenic diet with a naturopathic doctor to be sure that it is safe given your current health status and prior health history. I would also recommend that you incorporate this pattern of eating very slowly to prevent any uncomfortable side effects.

By Neal Malik, DrPH, MPH, RDN, assistant professor and core faculty at Bastyr University California.