Dietitian Warns Against Popular ‘Low-Carb’ Diets

Before you grab another quick “low-carb” chocolate bar, you might want to reconsider whether a low-carbohydrate diet is right for you. While the latest popular low-carbohydrate diets may work for some people in the short-run, a nutrition expert at Yale-New Haven Hospital is concerned about health risks down the road.

“There is no proof that these diets work in the long run, and cutting out carbohydrates while eating more protein and fat can have serious side effects,” said Ellen Liskov, a registered dietitian at Yale-New Haven Hospital.

Popular eating plans such as the Atkins and South Beach diets restrict carbohydrates and allow protein and fats in the initial phases, gradually adding more carbohydrates later on. A carbohydrate is a nutrient whose main function is to supply energy to the body, and recent research shows that people who replace carbohydrates with proteins and fats (including cheeseburgers, bacon, cheese, and butter) are effective at losing weight in the short run. The long-term effects of eliminating carbohydrates have yet to be fully investigated.

Meanwhile, some people are missing out on important nutrients as they jump on the latest bandwagon, Ms Liskov said. “Cutting out food groups that contain carbohydrates also cuts out a whole area of vitamins, minerals, and fiber,” she said. “People are avoiding fruit, whole grains, and even milk because they contain carbohydrates. From what I see in my practice, people across the board will consistently cheat on sugars including candies and bakery goods to compensate. They are not satisfied at meals, so they make very poor choices between meals because their bodies are hungry.”

For some, the result is low energy. Dieters who consume a lot of saturated fat, cholesterol, and minimal fiber also risk high cholesterol levels, constipation, and rapid weight gain once they stop the diet. In extreme cases, when a high protein diet is extremely low in carbohydrates, the body begins to break down fat down very quickly. This increases the risk of gout, kidney and liver problems, electrolyte abnormalities, dehydration, and bad breath. It is especially dangerous during pregnancy and for individuals with diabetes.           

“Most people would do better to try a well-balanced approach to losing weight,” Ms Liskov said. Those who continue to follow a high protein, low-carbohydrate diet can stay on the safe side by choosing the leanest protein sources, taking multiple vitamin and calcium supplements, and using unsaturated fats such as olive or canola oil instead of butter. Don’t eliminate all carbohydrates — include vegetables, whole fruits, and high fiber starches such as dried beans, lentils, and bran or oatmeal.