A comprehensive study from Australia raises concerns about the long-term effectiveness and safety of low-carb diets, commonly associated with weight loss and blood sugar management. While such diets can aid those with diabetes, the findings suggest they may increase the risk of type 2 diabetes for others if not properly balanced.
A long-term study led by researchers from Monash University and RMIT University has cast doubt on the long-term benefits of low-carbohydrate diets, such as the keto diet, which have gained popularity for weight loss and blood sugar management.
While low-carb diets can be beneficial for managing weight and blood sugar levels in individuals with diabetes, the 17-year study, conducted in Australia, questions their overall safety and effectiveness for individuals without diabetes. The researchers suggest that, if refined sugars and starches are not substituted with appropriate foods, a low-carb diet might inadvertently heighten the risk of developing type 2 diabetes.
The researchers emphasize that “a healthy diet is essential for the prevention and management of type 2 diabetes,” but note that the optimal diet for prevention may differ from that recommended for managing the condition.
To explore these concerns, the team analyzed health data from nearly 40,000 Melbourne residents recruited between 1990 and 1994. Participants’ socioeconomic, health, and nutritional information was gathered at the start of the study and again during follow-ups between 1995-1998 and 2003-2007.
Participants were assigned a low-carbohydrate score, which assessed the proportion of their energy intake from carbohydrates relative to fats and proteins, rather than the absolute amount of carbohydrates consumed. Those in the top 20 percent of this score obtained approximately 38 percent of their energy from carbohydrates, while those in the bottom 20 percent derived about 55 percent from carbohydrates.
The study found that individuals who consumed the fewest carbohydrates were 20 percent more likely to develop type 2 diabetes over the course of the study compared to those who consumed the most carbohydrates. The increased risk was primarily attributed to a higher body mass index (BMI) among those on the low-carb diets.
The researchers suggest that the increased risk of type 2 diabetes could be linked to the high fat content, particularly unsaturated fats, in low-carb diets. Those consuming fewer carbohydrates also tended to have lower fiber intake and higher consumption of protein and fat.
These findings indicate that focusing solely on carbohydrate reduction may not be sufficient. The researchers argue that other dietary factors also need consideration.
The study aligns with other recent research questioning the safety of keto diets, which advocate a low-carb, high-fat eating pattern. For example, an earlier analysis highlighted a troubling association between the keto diet and an increased risk of heart disease, stroke, type 2 diabetes, and irritable bowel disease.
The evidence underscores the importance of a well-balanced diet as a preventive measure against metabolic diseases. While eliminating refined sugars and starches can be beneficial, replacing them with saturated fats may lead to new health issues, according to the study’s conclusions.