A low-carb diet may be the best option for people looking to reverse metabolic syndrome, according to a recent study. Researchers compared the effects of three eating styles: low-carb, Mediterranean, and low-fat plant-based diets. They found that participants who lost weight on a low-carb diet showed improved liver insulin sensitivity, a key marker of metabolic health. This diet, comprising 4% carbohydrates, 73% fat, and 23% protein, led to improved liver insulin sensitivity.
The study, published in Cell Metabolism, involved 55 volunteers with metabolically unhealthy obesity. Participants were randomly assigned to one of the three diets, with 17 on low-carb, 18 on Mediterranean, and 20 on low-fat. They followed these diets for five months of weight loss and an additional period of maintenance.
The Study’s Findings
All diets helped participants lose weight and improve muscle insulin resistance, while also reducing LDL cholesterol, apolipoprotein B, and 24-hour plasma triglyceride concentrations comparably. Interestingly, macro composition did not affect whether fat or muscle was lost preferentially.
The low-carb group also saw significant improvements in kidney function and a reduction in liver-produced triglycerides. The findings highlight the potential of low-carb diets in reversing prediabetes and improving liver health, particularly relevant given the rising global concern over non-alcoholic fatty liver disease.
Why This Matters
Metabolic syndrome increases the risk of heart disease, stroke, and type 2 diabetes. While weight loss improves metabolic health, this study suggests that diet composition plays a key role in the type of weight lost and the extent of metabolic improvements. The low-carb diet’s ability to enhance liver insulin sensitivity and kidney function shows its potential in managing these conditions.
Diet Composition and Metabolic Health
The study’s findings emphasize the significance of macronutrient composition in metabolic health, especially for individuals with metabolically unhealthy obesity. While all diets helped participants lose weight and improve muscle insulin resistance, the low-carb diet’s improvement in liver insulin sensitivity was a notable result.
Impact on Kidney Function and Prediabetes
The low-carb diet’s benefits extended to kidney function, with significant improvements compared to other groups. It also proved effective in reversing prediabetes. Both the low-carb and Mediterranean diets reduced liver-produced triglycerides.
Study Design and Participant Experience
The study’s rigorous design included a randomized trial with 55 participants, who received weekly meal kits from the Washington University Metabolic Kitchen. Each kit contained main courses (500 Calories) and snacks (78–300 Calories), tailored to each diet’s macronutrient requirements. Participants logged their food intake online and received weekly dietitian advice.
Sources:
Petersen MC, Smith GI, Farabi SS, et al. Effect of diet macronutrient content on the cardiometabolic response to weight loss: A randomized clinical trial. Cell Metabolism. 2026;38(10):2006-2017.e5. doi:10.1016/j.cmet.2026.07.020
Washington University School of Medicine. Complex Effects of Dietary Manipulation on Metabolic Function, Inflammation and Health. clinicaltrials.gov; 2026. Accessed October 20, 2026.