A new study has found that diets low in carbohydrates and high in fats, which have become popular for weight loss, could actually elevate the risk of developing type 2 diabetes by 20%. This research underscores the importance of maintaining a balanced diet, according to the study’s authors.
Despite ongoing public health efforts, the incidence of type 2 diabetes (T2D) continues to climb in developed nations. While the adverse effects of poor-quality diets on diabetes risk have been established, the impact of low-carb, high-fat diets on this risk has remained unclear. Researchers from Monash University and RMIT University in Melbourne sought to address this gap through a comprehensive long-term study.
Professor Barbora De Courten from Monash’s Department of Medicine and RMIT’s School of Health and Biomedical Sciences, who co-led the study, explained, “We know that diets high in processed carbohydrates, low in fiber, and rich in refined sugars contribute to weight gain. This, in turn, can lead to increased insulin resistance and higher risk of type 2 diabetes.”
“Previous research has focused on low-carb diets primarily for managing or reversing existing diabetes, but our study reveals that such diets might increase the long-term risk of T2D, potentially due to increased fat consumption and low fiber intake,” she added.
The study, which used data from the Melbourne Collaborative Cohort Study (MCCS), analyzed the dietary habits of 39,185 adults aged 40 to 69. Participants were recruited between 1990 and 1994 and followed for up to 17 years. The research team evaluated the correlation between low-carbohydrate diets (LCD) and the risk of developing T2D later in life.
The study calculated an LCD score based on the percentage of energy derived from carbohydrates, fats, and proteins. A higher LCD score indicated a diet low in carbohydrates but high in proteins and fats. The results showed a positive association between high LCD scores and increased diabetes risk. Specifically, individuals who derived 38% of their energy from carbohydrates faced a 20% higher risk of T2D compared to those who got 55% of their energy from carbs. Obesity was found to mediate 76% of this risk association.
“We have demonstrated that a high low-carbohydrate diet score may increase the long-term risk of type 2 diabetes, with obesity playing a significant role in this relationship,” the researchers stated. “This might be due to the high fat content in these diets, particularly unsaturated fats. Thus, addressing only one aspect of diet might not be sufficient; a more holistic approach to dietary choices is necessary.”
The study suggests adopting a balanced diet, with the Mediterranean diet being highlighted as a potentially effective option for preventing type 2 diabetes.
However, the research acknowledges limitations, including the use of 16-year-old data and reliance on self-reported dietary information. Despite these constraints, the large sample size and extended follow-up period lend significant weight to the findings. The researchers call for further studies, including clinical trials, to explore the effects of low-carbohydrate diets with varying carbohydrate sources on diabetes risk.
