Paulette Lambert, R.D., C.D.E
Chief Dietitian at California Health & Longevity Institute
The newly touted ketogenic diet, known as a low carbohydrate, adequate-to-low protein, and very high fat regimen, changes the way your body is fueled. This diet forces you body to fuel off of fat rather than carbohydrates, when it typically fuels off of these carbohydrates and glucose for strength and brain functionality. The basic concept of the ketogenic diet is to switch the main fuel supply from carbohydrates to ketones. A ketone is a molecule that your body forms when you don’t burn carbohydrates correctly, changing the PH of your blood to be more acidic than normal. In extreme conditions where carbohydrates are used up, the liver can convert fat into ketones that your body can use for fuel. During this process, the blood sugar remains normal due to conversion of these ketones into glucose.
This diet has been used as early as 1920 to treat epilepsy in medication-resistant patients, and since 1960 to treat obesity. More recent application for the regimen has been towards treating diabetes, dementia, Alzheimer’s, and cancer; all medical concerns with possible issues with defects in normal utilization of energy. Today, many athletes are using it to try to improved performance while others use it for quick weight loss. Here is what the recent studies show:
Recent scientific studies look promising in terms of the treatment of certain disease, but medical evidence is not yet conclusive. In other words, do not ditch your prescribed medications and other treatments. If one wants to attempt these treatments for a specific medical concern, it is very important to have medical supervision.
In one year, the weight loss in those on the ketogenic diet was no better than a balanced diet with good quality carbohydrates and less saturated fat. Weight loss itself is what improves glucose levels, blood lipids, and lowers blood pressure, not the state of ketosis. Those on a balanced diet went on to lose more weight than those on the ketogenic diet, possibly because the adherence to the balanced diet was much easier.
The ketogenic diet showed no improvement in endurance performance in athletes; high intensity and high carbohydrate availability lead to improved performance. Most endurance sports are intermittent-intensity sports rather than steady state intensity activities. Studies of athletes who have adopted to ketosis burn more fat but do not produce more work (go faster). If speed increases, it is often due to weight loss due to caloric restriction. Athletes need to optimize their ability to use all fuels and provide their body with adequate supply of all fuels to see results.
The ketogenic diet does not improve body composition and loss of weight is not any different on this diet than any other diet that reduces calories from any source. The ketogenic diet also does not help in improving strength.
-The reduced fiber, lack of fruit, and potential for increase of saturated fats (depending on the types of fat consumed), can increase long-term cardiovascular risk factors
-Supplementation is needed in the ketogenic diet due to low level of water soluble vitamins
-Nutrient deficiencies and initial stress of the diet can cause hair loss
-Increase in kidney stone formation
-Gastrointestinal distress due to high fat content
-Initial increase in fatigue
While there may be some benefits in doing the ketogenic diet for those suffering from a severe chronic disease, it is not realistic nor desirable health-wise for most of the population to adopt this lifestyle in the long-term. As a health expert, it is my job to review studies and check for sound medical evidence before making recommendations. Unfortunately, the food industry with help from the internet, will often use research before proving safety or effectiveness in order to spin a “trendy” way to promote products. Experience tells me this may be the next new packaged food and supplement line that promises us everything but fails to deliver.