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Bottomline upfront: the ketogenic diet may not be the quick fix to weight loss that individuals are looking for. Typically, the diet only works for weight loss in the short term, and it can be unhealthy.
The Ketogenic Diet, also called the High Fat, Low Carb (HFLC) diet, is a new diet fad. When following the diet, a person eats less then 50 grams of carbohydrates a day, the RDA for protein (0.8g/kg of body weight), and the rest of the calories from fat. The diet claims to help individuals lose body fat and improve athletic performance by making the body burn fat stores instead of carbs. But what does this all mean and does the diet actually work?
To understand the ketogenic diet, you must first understand how the body processes foods. Normally, the carbohydrates contained in food are converted into glucose, which is transported around the body and fuels our brains. However, if there are very few carbohydrates in the diet, the liver converts foods into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. When our bodies convert food into fat and not glucose, we are said to be in ketosis.
The ketogenic diet was first developed to help children with epilepsy as the pediatric brain seems to have fewer seizures when the body is in ketosis. Research has shown that the ketogenic diet may also be beneficial in treating the symptoms of adult epilepsy and Alzheimer's disease; however, more research is still needed in these areas.
In terms of weight loss, websites and diet blogs claim that the diet uses your body fat as fuel so that you lose high amounts of body fat. These sites also claim that the ketogenic diet helps you to decrease your hunger and cravings. Research studies looking at the ketogenic diet have found no benefits in terms of fat loss or athletic performance. In fact, studies have shown that following the ketogenic diet may result in high amounts of muscle loss, which can decrease athletic performance, and make weight loss and maintenance more difficult. Studies looking only at weight loss have found that individuals following a ketogenic diet can lose significant amounts of weight, but much like any low carb diet, weight maintenance is difficult, with most individuals gaining back the weight.
Side effects of the ketogenic diet include kidney stones, headache, hair loss, low blood sugar, hypoglycemia, fatigue, and dizziness. Individuals following a ketogenic diet also risk deficiencies of certain vitamins and minerals, such as Vitamins C, folic acid, and B6, as well as calcium and potassium, since the diet cuts out fruits, grains, and many dairy products. It is also important a person watches which fats they choose to eat on the diet, as consuming high amounts of saturated fat has been shown to increase a person's risk of heart disease.
Overall, the ketogenic diet may not be the quick fix to weight loss that individuals are looking for. Typically, the diet only works for weight loss in the short term, and it can be unhealthy. However, if you are looking for a diet to help with epilepsy, this may be the lifestyle change for you.
Lauren Ptomey PhD, RD, LD is an Assistant Research Professor for the Department of Internal Medicine at the University of Kansas Medical Center. She has over a decade of experience working within the research field with expertise in weight management, energy balance, and physical activity in both the general and special needs populations.