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by Michele Tuttle

February 8, 2021

Here's what you need to know about this popular diet

You’ve heard the stories and probably have a friend or three who swears that the keto diet has changed their lives. Now you’re wondering if perhaps it’s a good answer for those extra pounds around your middle.

In a word, NO.

Keto is a low- to no-carbohydrate diet that’s high in protein and fat and was originally developed to control epileptic seizures. It forces the body to use an inefficient metabolic pathway to convert protein and/or fat to glucose that our bodies and brains need.

It works because most of us eat a diet centered around carbohydrates and when we instead eat only protein and fat, we eat fewer calories because it simply isn’t very palatable or sustainable to eat most of calories from fat and protein.

Keto forces people to stop snacking on chips, crackers, and desserts, which reduces calories. So, yes, people DO lose weight on this diet. But NOT because the diet is magic, but because they reduce calories by not eating the foods they typically eat.

So, what’s the problem? There are three major reasons that swimmers (and all endurance athletes) should be wary of any diet exceptionally low in carbohydrates such as keto:

  1. Following a ketogenic diet depletes the body of glycogen, which directly impacts performance. For athletes, this means giving up the fuel that drives your workouts. And, if you care about being fast, it limits your top end speed since anaerobic exercise (sprinting) requires glucose.
  2. Diets such as keto that are low in carbohydrates are also very low in fiber, a nutrient that’s critical to our gut and overall health. Foods such as beans, peas, whole grain wheat, corn, and oats supply much more fiber than fruits and vegetables. Our digestive enzymes can’t break down fiber, but microbes in our large intestine can, producing short-chain fatty acids such as butyrate. Butyrate is linked with better glucose regulation, immune function, and a lower risk of cardiovascular disease.
  3. Diets high in protein and fat must be treated very carefully because after short-term use they are linked with increased risk of bone fracture. Keto diets are typically low in calcium because they omit dairy products, but lack of carbohydrate appears to impact the entire bone remodeling process.

Bottom line: Any diet that omits major food categories may appear to work in the short term for weight loss but the cost to overall health can be extremely high. So, if you’re looking for a way to reduce your waistline, consider increasing fiber gradually by eating more beans, whole grains, fruits and vegetables, along with increasing strength training at the gym.


  • Health and Nutrition


  • Diets