The ketogenic, or keto, diet has been around for decades. Just like music and fashion trends that repeat over the years, this diet is seeing a resurgence in popularity.
To learn the keto basics, we spoke with endocrinologist Dr. Katy Brown, who studies nutrition and metabolism as they relate to health and disease, with a primary focus on diabetes and obesity.
“An endocrinologist’s role is to carefully evaluate and relay the pros and cons, or risks and benefits, from a science and medicine perspective, of any meal plan a patient is considering,” Brown says.
Keto basics: What does keto mean?
Keto is shorthand for ketogenic, which describes anything that is related to or causes ketogenesis — the production of ketones, compounds that can be made and used by the body as an alternative fuel source.
“We get our energy from different macronutrient fuel sources such as carbs, proteins and fats in our diet,” Brown says. “Ketones are a fat- and protein-derived fuel.
“When you eat carbs, the body will store what you don’t immediately need for energy and later release the glucose to keep your brain and body going while you’re not eating. Once those glucose stores are depleted, the brain needs another source of energy, so the body will produce ketones from fat and protein stores.”
That metabolic state, characterized by raised levels of ketones, is called ketosis. The keto diet intentionally puts the body in nutritional ketosis as a result of severely restricting carbohydrate intake.
Keto basics: How does the keto diet work?
The diet is similar to other low-carb diets, but it takes that strategy to an extreme level by allowing fewer than 20-50 grams of net carbohydrates per day to keep the body in a state of ketosis.
In addition to grains and processed foods like chips and pretzels (what most people think of when they think of carbs), this diet discourages eating many foods in which carbohydrates are found naturally.
Dr. Brown offers this example:
- 1 cup of blueberries contains 21 grams of total carbs
- 1 cup of corn contains 30 grams of carbs
- 1 cup of plain Greek yogurt contains 11 grams of carbs
“If you consume all three of these foods in one day, you would be over your carb limit on the keto diet,” she says. “Many people count only net carbs [by subtracting dietary fiber from the total carb count], but this method still greatly restricts carbs that come from fruit, starchy vegetables, dairy and legumes — all foods that are considered to be part of a healthy meal plan.”
In the keto diet, calories from high-fat foods such as cheese, meat and oil replace the omitted carbs.
“There’s a little more risk involved because your LDL [bad cholesterol] can markedly increase depending on the types of fats you’re eating,” Brown says. “It’s important that lipids and additional vital measures of health are monitored by an experienced physician and registered dietitian.”
You have to know what you’re depriving your body of and a safe way to put it back in. With professional guidance, supplements can be taken to compensate for nutrients that the ketogenic diet tends to be deficient in (e.g., calcium, fiber, magnesium, potassium).
Gold’s Gym Pro-Shop has a selection of keto-related products, including supplements, at some of its locations:
- PrimaForce KetoShake, a meal replacement shake available in two flavors.
- PrimaForce BHB (beta-hydroxybutyrate), a supplement drink available in two flavors.
- Finaflex Ketone Strips, for urinalysis testing of ketone presence and concentration (the easiest way to tell if the body is in ketosis).
Keto basics: Is the keto diet right for me?
Any diet or lifestyle change is only successful if it is maintained, and every person’s commitment to that kind of change depends on his or her overall health and fitness goal.
“If your goal is weight loss, the best plan is the one you’re able to adhere to,” Brown says. “For some people, the ketogenic diet is a viable plan.”
For others, the keto diet may be unrealistic to sustain. Some studies show it may cause vitamin and mineral deficiencies (that could lead to bone weakness), constipation and kidney stones, in addition to the LDL increase mentioned above.
No matter which diet you’re considering, the advice is the same: Know your goal and consult with a health professional who can help you get started safely.