Summary:
In individuals with type 2 diabetes or prediabetes ,an anti-lipogenic low-carbohydrate high polyunsaturated fat diet (LCPUFA) or a healthy Nordic diet (HND) significantly reduced liver fat content and improved cardiometabolic parameters compared to usual care (UC),
though it was associated with some gastrointestinal side effects and challenges in dietary adherence.
| PICO | Description |
|---|---|
| Population | Adults diagnosed with type 2 diabetes or prediabetes, characterized by metabolic dysregulation and increased liver fat. |
| Intervention | An anti-lipogenic low-carbohydrate high polyunsaturated fatty acid diet (LCPUFA) or a healthy Nordic diet (HND) rich in whole grains, applied over 12 months. |
| Comparison | Usual care (UC) without specific dietary interventions. |
| Outcome | Both LCPUFA and HND significantly reduced liver fat content compared to usual care and improved glycemic control and lipid profiles. Mild gastrointestinal side effects were reported, and dietary adherence varied among participants. |
Clinical Context
Non-alcoholic fatty liver disease (NAFLD) affects the majority of patients with type 2 diabetes and represents a major contributor to hepatic and cardiometabolic morbidity. Hepatic steatosis drives insulin resistance, dyslipidemia, and systemic inflammation while increasing risk for progressive liver disease including fibrosis and hepatocellular carcinoma. Dietary intervention represents a cornerstone of NAFLD management, yet optimal macronutrient composition remains debated. Low-carbohydrate diets may reduce hepatic de novo lipogenesis, the metabolic pathway creating fat from carbohydrate excess, while polyunsaturated fatty acids have demonstrated anti-lipogenic and anti-inflammatory effects in the liver. The healthy Nordic diet emphasizes whole grains, berries, fish, and rapeseed oil consistent with regional food traditions while providing a moderately low glycemic load. This three-arm randomized trial directly compared two distinct dietary approaches against usual care to determine their relative effects on liver fat content and cardiometabolic parameters over 12 months.
Clinical Pearls
- Both the low-carbohydrate high polyunsaturated fat diet and healthy Nordic diet significantly reduced liver fat content compared to usual care, demonstrating that structured dietary intervention provides meaningful hepatic benefits.
- Improvements in glycemic control and lipid profiles accompanied the liver fat reduction, suggesting comprehensive cardiometabolic benefits from these dietary approaches.
- The 12-month study duration provides evidence for sustained dietary effects beyond short-term metabolic studies.
- Dietary adherence varied among participants, highlighting the real-world challenge of maintaining dietary changes long-term regardless of the specific pattern prescribed.
Practical Application
Clinicians managing patients with type 2 diabetes or prediabetes and fatty liver disease should recommend structured dietary interventions rather than relying solely on general lifestyle advice. Both the low-carbohydrate high polyunsaturated fat approach and healthy Nordic diet pattern represent evidence-based options that can be tailored to patient preferences and cultural food traditions. For patients comfortable with carbohydrate restriction, the LCPUFA approach may be appropriate, while those preferring a more traditional diet structure may find the healthy Nordic pattern more sustainable. Referral to registered dietitians for individualized meal planning and ongoing support can address the adherence challenges identified in this trial. The mild gastrointestinal symptoms reported should be discussed proactively to prepare patients and optimize tolerance.
Broader Evidence Context
The NAFLDiet trial contributes important randomized evidence to the dietary management of fatty liver disease in diabetes. Prior studies have demonstrated liver fat reduction with various dietary approaches including Mediterranean diet, low-carbohydrate diets, and caloric restriction. This trial’s strength lies in comparing two distinct dietary philosophies head-to-head against usual care over a clinically relevant duration. The finding that both interventions proved effective reinforces the principle that multiple dietary patterns can achieve hepatic benefits, allowing flexibility in dietary prescription. The emphasis on polyunsaturated rather than saturated fat in the low-carbohydrate arm addresses concerns about cardiovascular effects of traditional low-carbohydrate approaches heavy in saturated fat.
Study Limitations
- Specific liver fat reduction magnitudes for each dietary intervention versus usual care were not detailed in the summary.
- Whether one dietary approach proved superior to the other for liver fat reduction was not specified.
- The nature and severity of gastrointestinal side effects were not characterized.
- Histological liver outcomes such as fibrosis improvement were not assessed, limiting conclusions about disease progression.
- Long-term follow-up beyond 12 months and sustainability of benefits with dietary relaxation are unknown.
Bottom Line
Both a low-carbohydrate high polyunsaturated fat diet and a healthy Nordic diet significantly reduce liver fat and improve cardiometabolic parameters in patients with type 2 diabetes or prediabetes compared to usual care over 12 months. Clinicians should recommend structured dietary interventions for fatty liver disease management, choosing between patterns based on patient preferences and adherence potential.
Source: Fridén, Michael, et al. “Effects of an anti-lipogenic low-carbohydrate high polyunsaturated fat diet or a healthy Nordic diet versus usual care on liver fat and cardiometabolic disorders in type 2 diabetes or prediabetes: a randomized controlled trial (NAFLDiet).” Read article here.
