Take It In: Ketogenic diet is in vogue, but does it work?

Apr 15, 2018 by Carol Bareuther

Take It In: by Carol Bareuther

A diet first developed by a faith healer in the 1920s to help prevent seizures in children with epilepsy is making a comeback. But this time it’s for the contemporary holy grail of weight loss. The ketogenic diet is a high-fat, moderate-protein, low-carbohydrate formula. The fact that celebrities suddenly latched onto this slimming plan last year sent the ketogenic diet into the ranks of the Top 10 Googled diets in 2017.

The idea of eating platefuls of bacon and eggs and still losing weight isn’t hard to swallow, and it’s a big part of the diet’s appeal. But does the ketogenic diet really work? And more importantly, is it safe? The answers lie in a large body of recent research.

The ketogenic diet takes its name from the metabolite the body produces when fat rather than sugar is the primary fuel available. In a nutshell, the sugar glucose is the body’s primary fuel, much like gasoline powers cars. When there are too few dietary carbs available, the body turns to carbs stored in muscles – called glycogen – and breaks them down. This leads to a pleasant surprise on the scales due to lost water weight, since water is normally stored along with muscle glycogen. Thus, the initial weight loss on a ketogenic diet is water, not body fat. When the glycogen is gone, the body turns to stored fat for fuel. This results in a build-up of acids called ketones and a metabolic state called ketosis. For those following a ketogenic diet to lose weight, ketosis is the brass ring they hope to achieve.

The formula for a ketogenic diet calls for 70 percent of calories from fat, 25 percent from protein and a miniscule 5 percent from carbohydrates. This translates into daily meals of high-fat meats, dairy, eggs, nuts and seeds, and produce such as avocados. Forbidden are grains, such as breads, cereals, rice and pasta; added sugar in any form; fruit; and starchy vegetables, such as potatoes and yams. A sample diet for a day might include fried eggs and bacon for breakfast; a green salad with ham, cheese and avocado slices for lunch; steak with asparagus for dinner; and snacks like cheese cubes, boiled eggs, nuts or beef jerky.

Does the ketogenic diet work? Yes, according to research published in the British Journal of Nutrition in 2013. In this study, subjects were fed either a ketogenic diet or traditional low-fat weight-loss diet. Results showed that those on the ketogenic diet lost more weight and showed greater improvements in blood pressure and blood fats like triglycerides and LDL (bad) cholesterol than those on a low-fat diet.

Is a ketogenic diet it safe? Yes and no. Yes, according to a study published in a 2004 edition of the journal Experimental & Clinical Cardiology, which revealed that obese men and women who were on a ketogenic diet for up to 6 months lost weight and improved blood indices of heart health. Interestingly, these researchers based most of the test ketogenic diet on healthful monounsaturated and polyunsaturated fats. Nuts, seeds, avocado, plant-based oils and olives all contain healthful fats. On the other hand, the answer is no in terms of safety since the diet is deficient in fruit and vegetables. Fresh produce contains key nutrients and phytonutrients that can help to prevent chronic diseases.

The bottom line is that any benefits achieved on a ketogenic diet can easily be lost if care isn’t taken when going off the diet. Specifically, there should be a gradual reduction in fat intake and reintroduction of more carbohydrates – especially carbs such as low-calorie fruits, vegetables and whole grains. Reverting to the eating habits that led to obesity in the first place is only going to pile on the unwanted pounds again.

Carol Bareuther is a registered dietitian and freelance health and nutrition writer. Comments are welcome below.