In a (very) long term study of nearly 400,000 participants aged 50-71, it was found that those eating low fat diets had significantly reduced overall mortality “by 18%, cardiovascular mortality by 16%, and cancer mortality by 18%” (1).
The study differentiated between healthy and unhealthy diets for both low carb and low fat versions. For example, “the high quality [healthy] carbohydrates included carbohydrates from whole grains, whole fruits, legumes, and non-starchy vegetables…low quality carbohydrates included carbohydrates from refined grains, added sugar, fruit juice, and starchy vegetables” (1). In terms of fats, consuming a low saturated fat diet was categorized as being healthier than diets low in unsaturated fats (1). Eating any low fat diet was associated with improved mortality. Eating a healthy low carb diet was actually associated with a “marginally lower total mortality” (1). But it comes down to this: low fat diets were healthier than low carb diets.
Although I personally do not feel that ketogenic or low carb diets are healthy, there are a few points to consider if you are thinking about changing from a ketogenic diet to a lower fat diet based on the results of this study.
First, if your low carb diet is working well for you, consider whether the risk of quitting and gaining weight is greater than the risk of this type of diet. If you are technically at a healthy weight, it may not be worth the continued risk. But if you have severe obesity, it may be a more serious problem to stay at a high weight. Please check with your physician or dietician to determine the best course of action.
Second, people younger than 50 were not part of this study. The scientists also noted that most of the participants were non-Hispanic and college educated. So it’s difficult to say if these findings would apply to every adult.
And finally, although some media outlets have chosen not to report on this, those eating healthy keto type diets did not have increased deaths. It may not be optimal for health, but these diets may be effective for some people. For example, the Daily Mail reported the following, just below the headline Low Carb Diets INCREASE Your Risk of an Early Death (2).
- “Eating a low fat diet can reduce your risk of early death up to 34 percent
- Meanwhile, a diet low in carbs can raise mortality risk by around 38 percent” (2).
As usual, the media chooses to highlight the most extreme parts of any story. I did not see those particular numbers in the study, but check the first footnote to read the study for yourself.
So is there a way to “have your cake and eat it too”? Perhaps if you try a healthy keto diet plan similar to this one from the Mayo Clinic (3):
The link above is for a one week sample menu which will give you a few recipes and an idea of what to expect if you followed this diet. It is one of six options for the Mayo Clinic Diet online program. I have tried the original and higher protein versions with success, but not this particular one. Please comment below if you have, or share a different healthy low carb diet.
Even though the Mayo Clinic has provided this plan, they don’t recommend most ketogenic diets for long term health (3). It’s important to remember the original reason for this way of eating:
Over one hundred years ago Dr. Wilder, a doctor at the Mayo Clinic, developed the ketogenic “keto” diet to treat children with severe epilepsy. Since then, the keto diet has been successfully used around the world to treat drug-resistant epilepsy. In the 1970s, the diet became popular for weight loss thanks to the Atkins diet, which catapulted keto into the weight-loss limelight. While the Atkins diet recommends slowly reintroducing carbohydrate-containing foods back into your eating plan, the keto diet strictly limits these foods at all times (4).
So this type of diet was not designed for long term use or for adults. If you’re using it in that way, please consult your doctor or registered dietician for the best way to maintain your weight, and most importantly, your health!