Metabolic Syndrome, Obesity

Personalizing Obesity Treatment: Real-World Comparison of a Very-Low-Calorie Ketogenic Diet Versus a Whole-Food Mediterranean Ketogenic

This real-world prospective study compared two ketogenic approaches for obesity management: a very-low-calorie ketogenic diet (VLCKD) using meal replacements and a whole-food Mediterranean ketogenic diet (MedKD). The study aimed to determine whether MedKD could achieve comparable weight loss and metabolic improvements to VLCKD over 3 months.

A total of 62 adults with obesity were enrolled in a non-randomized, preference-based design reflecting routine clinical practice, and 55 participants completed the study (27 VLCKD, 28 MedKD). The primary outcome was percentage weight loss, with secondary outcomes including waist circumference, insulin resistance (HOMA-IR), lipid profile, renal function, and tolerability.

The VLCKD provided approximately 600–800 calories per day, primarily through meal replacements with very low carbohydrate intake (≤50 g/day), moderate protein, and limited fat. In contrast, the MedKD used whole foods with a moderate caloric intake of ~1200–1500 kcal/day, maintaining carbohydrate restriction (<50 g/day) while emphasizing Mediterranean-style foods such as olive oil, fish, eggs, nuts, and non-starchy vegetables.

Both interventions produced substantial and comparable weight loss and metabolic improvements. Despite differences in caloric intake and dietary composition, outcomes were broadly similar. Importantly, the MedKDgroup had worse baseline metabolic profiles – including higher insulin resistance, triglycerides, and a greater prevalence of diabetes – which may have influenced the magnitude of observed improvements.

Results / Key Findings

Weight Loss & Anthropometrics

• Both groups achieved average weight loss of ~33 lb (15 kg), representing a ~15% reduction in body weight
• Significant decreases in BMI, waist circumference, and waist-to-height ratio in both groups, with no significant between-group differences

Glycemic Control & Insulin Resistance

• Fasting glucose decreased in both groups
• HOMA-IR improved significantly in both groups
• Greater reduction in HOMA-IR observed in the MedKD group

Lipid Profile

• Triglycerides decreased significantly in both groups
• LDL cholesterol declined modestly; HDL remained stable (MedKD) or slightly decreased (VLCKD)

Renal & Liver Markers

• Serum creatinine decreased in VLCKD and slightly increased in MedKD (within normal range)
• Liver enzymes and electrolytes improved similarly in both groups

Tolerability & Safety

• No serious adverse events reported
• Mild gastrointestinal symptoms were transient and comparable between groups

Conclusion

Over 3 months, a whole-food Mediterranean ketogenic diet with mild caloric reduction achieved weight loss and metabolic improvements comparable to a very-low-calorie ketogenic diet. These findings support MedKDas a flexible and feasible alternative to VLCKD and highlight the role of personalized dietary strategies in obesity management.