Q. Okay, I have a question. Many of my friends are losing weight on a Keto Diet and it is working. Why isn’t everyone on a Keto Diet?

A. I can think of several reasons.

First, diets do not work well in the long term as the body dislikes deprivation. Refraining from gaining weight is always better than trying to lose it once the pounds have packed on. You have heard me say Prevention Beats Cure Every Time.

Second, a Keto diet recommends keeping an intake of carbohydrates to an absolute minimum. This results in the body burning fat rather than carbs for energy, which helps lose weight. However, if you don’t change your lifestyle, studies show that most people gain back all they lost—and more—within a period of about three years. Unfortunately, this comes back as a higher percentage of body fat and less muscle.

Third, burning fat for energy produces ketones, an acid that reportedly has some benefits but that can negatively impact bone tissue over time. Some of the foods included in a keto diet (e.g., cheese, eggs, fish, and meat) are acid-forming. As acidity increases in the body, the volume, strength, density, and thickness of bones can be reduced, which can lead to bone fractures.

Fourth, and most important in my brain’s opinion, the brain needs glucose to power its myriad chemical processes and to create energy. It prefers to get this glucose from carbohydrates—hopefully the healthiest carbs available. There is some concern about the quality of a person’s brain function over time when the brain receives an insufficient amount of healthy carbs.