Overweight, obesity, and type 2 diabetes remain two of the most significant health challenges of modern society. Despite advancements in treatment, rates of both conditions continue to rise—highlighting the need for more effective long-term strategies.
Why Diet Composition Matters in Diabetes Management
Type 2 diabetes and obesity often overlap, with blood glucose dysregulation serving as a core issue in both. One topic that continues to spark debate is how different macronutrient ratios influence weight, blood sugar control, and cardiovascular risk.
Low-carbohydrate diets have gained attention for their potential benefits in improving glycaemic control. However, traditional low-carb diets are often high in saturated fat—raising concerns about cardiovascular disease (CVD) risk.
To address this, researchers designed a study exploring the effects of a low-carbohydrate diet high in unsaturated fat, compared to a traditional low-fat diet, on diabetes and CVD-related health markers.
How the Researchers Compared Low-Carb and High-Carb Diets
The study was a 2-year randomised controlled trial. Participants were adults aged 35–68 with type 2 diabetes, a HbA1c ≥7.0% or using diabetes medications, and a BMI of 26–45 kg/m².
A total of 115 adults were randomised into two hypocaloric, energy-matched diet groups, both combined with exercise:
- Low-carbohydrate diet (LC): 14% carbs, 28% protein, 58% fat
- High-carbohydrate diet (HC): 53% carbs, 17% protein, 30% fat
Both groups limited saturated fat to under 10% of daily energy intake.
Measured outcomes included:
- HbA1c
- Glycaemic variability
- Medication requirements
- Weight and body composition
- CVD risk factors
- Renal markers
Key Findings From the 2-Year Trial
Sixty-one participants completed the full 2-year period. Both groups experienced meaningful improvements with no significant differences between them for key outcomes such as weight, body fat, fasting glucose, blood pressure, or HbA1c reductions.
Results included:
- LC group: average weight loss 6.8 kg
- HC group: average weight loss 6.6 kg
- HbA1c reduction: 0.6 (LC) vs 0.9 (HC)
However, the LC group demonstrated additional benefits, including:
- Greater reduction in diabetes medication use
- Improved glycaemic variability
- Lower triglyceride levels
- Better maintenance of HDL cholesterol
- Reduced LDL and improved other CVD markers
- No adverse renal effects
What the Results Mean for Managing Type 2 Diabetes
Both dietary approaches improved weight, body fat, blood pressure, and HbA1c levels over the two-year period. However, the low-carb, high-unsaturated-fat diet offered additional metabolic improvements beyond weight and glucose control.
These findings suggest that a low-carbohydrate diet rich in unsaturated fats may be a more effective long-term dietary approach for managing type 2 diabetes, particularly for reducing medication needs and improving blood lipid and glycaemic stability.
