The ketogenic backlash
A reader took offence over several of my statements in a recent column on ketogenic diets. Here are some excerpts, as space allows, followed by my responses:
Reader: “Greetings, Barbara. You write: Very low carbohydrate ketogenic diets severely limit the intake of sugars and starches (carbs) that are mostly found in plant-based foods such as fruit, vegetables, legumes (beans) and grains. You conveniently omitted the more nefarious dietary culprits of highly processed and manufactured food, HFCS, sugar, among others.”
BQ: By definition, carbohydrates are carbon, hydrogen and oxygen molecules that form sugars and starches when plants are exposed to energy from the sun. (Cows that eat plants can produce another carbohydrate-containing food, milk.) Carbohydrates are also the only source of dietary fibre in our diets.
I doubt anyone would argue that we need to limit overly processed carbohydrates. My point was that extremely low carbohydrate diets can overly restrict healthful plantbased foods as well as the bad boys.
Reader: “You write about the buildup of acids in the blood called ketones which happens when the body is starved of carbohydrates. You neglect the full definition of ketones which are fatty acids … as ketones are NOT acids but organic compounds.”
BQ: Ketones (or ketone bodies) are not fatty acids. They are formed when fatty acids are broken down for energy.
According to Medline Plus Medical Dictionary, ketone bodies are aceto-acetic acid, acetone, and a derivative of hydroxybutyric acid, i.e. organic acids.
Reader: “And in what biochemical universe could the body actually starve from lack of carbs? They are the only macronutrient unnecessary for human survival.”
BQ: The one nutrient absolutely necessary for human survival is glucose, a sugar most easily derived from the breakdown of carbohydrate foods. According to the Institute of Medicine, “glucose is the only energy source for red blood cells and the preferred energy source for the brain, central nervous system, placenta, and fetus.” Deprived of glucose, brain cells die. When glucose is not available from carbohydrate foods, protein and fat can be used by the liver to make glucose … a carbohydrate.
Reader: “Why do we need any more sugar/carbs in our diet when our body can produce any glucose required on its own?”
BQ: Experts agree we need more added sugar in our diets like we need a hole in our heads. Nutrition is more than energy, however. Foods such as whole grains, vegetables, fruit and legumes are rich in dietary fibre and other nutrients essential for optimal health.
Reader: “You write: ‘After a year … the overall success of low carb diets is similar to other plans, possibly because the diet is so difficult to maintain.’” As Jason Fung MD says: “The trick is finding a way of eating that works for you. There’s no such thing as a diet for all.”
BQ: I totally agree with you on this point. Emerging science is beginning to see how our unique genetic codes may one day determine our individual diet needs.