Low-carb, high-fat diets linked to significantly higher diabetes risk, study suggests

MELBOURNE — In recent years, low-carbohydrate diets have gained popularity as a weight loss strategy and potential treatment for Type 2 diabetes. However, a new study reveals that low-carb eating patterns are linked to a long-term increase the risk of developing the condition.

The study by Australian scientists uncovers a surprising link between low-carb diets and an increased risk of diabetes. Researchers from Monash University and RMIT University followed over 39,000 adults for nearly 14 years to investigate this relationship.

The study, published in the journal Diabetes and Metabolic Syndrome: Clinical Research and Reviews, found that people who adhered to a low-carbohydrate, high-fat, and high-protein diet had a 20% higher risk of developing Type 2 diabetes compared to those who ate a more balanced diet. This finding challenges the commonly held belief that cutting carbs is universally beneficial for metabolic health.

“Eating food high in saturated fats can lead to weight gain but we know they also lead to insulin resistance which is one of the causes of Type 2 diabetes independently of weight gain,” explains Distinguished Professor Barbora de Courten in a media release.

Before you rush to restock your pantry with pasta and bread, however, it’s important to understand the nuances of this research. The relationship between low-carb diets and diabetes risk isn’t as straightforward as it might seem at first glance. The researchers also note that this is an observational study and cannot prove that low-carb diets directly cause an increased diabetes risk.

The study utilized data from the Melbourne Collaborative Cohort Study, which recruited participants aged 40-69 between 1990 and 1994. Researchers analyzed dietary information collected at the start of the study and tracked new cases of diabetes reported by participants over the following years.

The researchers used a scoring system called the low-carbohydrate diet (LCD) score to measure how closely participants followed a low-carb eating pattern. This score was based on the percentage of total calories coming from carbohydrates, fat, and protein. A higher score indicated a diet lower in carbs and higher in fat and protein. The study divided participants into five groups based on their LCD scores.

Interestingly, the group with the highest LCD scores (meaning they ate the fewest carbs) consumed about 37.5% of their calories from carbohydrates. In contrast, the group with the lowest LCD scores got about 55.4% of their calories from carbs. To put this in perspective, many popular low-carb diets recommend getting less than 26% of calories from carbohydrates, which is even lower than the highest LCD score group in this study.

It’s important to note that not all low-carb diets are created equal. The study found that people with higher low-carb diet scores tended to consume more saturated fat and less fiber than those with lower scores. This suggests that the quality of fat and carbohydrates in the diet may be just as important as the quantity when it comes to diabetes risk.

The study also found some differences in lifestyle factors across the low-carbohydrate diet score groups. For example, the group with the highest scores had a higher proportion of current smokers, individuals with obesity, and lower physical activity levels compared to other groups – known risk factors for Type 2 diabetes.

When the researchers accounted for body mass index (BMI) in their analysis, the relationship between LCD score and diabetes risk disappeared. This suggests that the increased risk of diabetes associated with low-carb diets may be largely explained by differences in body weight.

“For people who don’t have diabetes, a balanced diet is the best choice,” de Courten says. “We need to remember that not all carbohydrates are equal. The kind of carbs you want to avoid are refined sugars such as soft drinks, juices, white rice, white bread and replace them with unprocessed carbs rich in fiber like grains, brown rice and legumes.”

“And eat more of healthy mono- and poly-unsaturated fats such as avocados, nuts, olive oil and fatty fish like salmon.”

The researchers note several limitations of their study, including its reliance on self-reported dietary data and the fact that they only measured diet at the beginning of the study period. They caution that eating patterns may have changed over time, which could affect the results.

As with any dietary change, it’s important to consult with a healthcare provider or registered dietitian before making significant shifts in your eating habits. They can help you develop a personalized nutrition plan that takes into account your individual health needs and risk factors.

This study serves as a reminder that there’s no one-size-fits-all approach to nutrition. While low-carb diets may be effective for short-term weight loss, their long-term impacts on health are still being understood. As always, a balanced diet, regular physical activity, and maintaining a healthy weight remain the cornerstones of diabetes prevention.

Note: An earlier version of this story mentioned Atkins and keto diets. While these are known low-carbohydrate diets, they were not specifically mentioned in the journal paper and are not representative of the diets followed in this study. We have removed the mentions of these specific diets from our text.