Successful weight loss in two adult patients diagnosed with late-onset long-chain fatty acid oxidation defect

Patients with long-chain fatty acid oxidation defect (LCFAOD) cannot tolerate fasting and are restricted in their physical activity, hence their increased risk of obesity. Experts therefore advise avoidance of catabolic situations and discourage weight reduction in these patients. Two patients with late-diagnosed LCFAOD undergoing treatment at two academic centers successfully lost weight under supervision of a metabolic dietitian. Patient 1 (male, 47 years) diagnosed with CPT 2 deficiency lost 10 kg body weight in a 3-month period with the help of an energy and LCT-restricted, MCT- and carbohydrate-rich diet in combination with an exercise program. CK levels, C16, C18, and C18:1 levels of his acylcarnitine profile and his blood pressure decreased during the period of weight reduction. Patient 2 (male, 39 years) has a VLCAD deficiency. Dietary advice was energy and LCT restriction, MCT and carbohydrate-enriched food with raw cornstarch added during the night. Patient 2 lost almost 40 kg body weight to 87.6 kg (BMI 25.1) in 2 years. CK, insulin, TG, and ALAT blood levels decreased. Conclusion: Weight reduction without loss of metabolic control seems possible in late-onset LCFAOD patients. No metabolic crisis occurred in these two patients, while the positive effects of weight reduction were clear. The residual enzyme function in late-onset LCFAOD may be one of the reasons that metabolic decompensation was prevented. In addition, dietary adjustments to prevent excessive fatty acid oxidation likely contributed as well. Therefore, expert supervision by a dietician specialized in metabolic diseases is recommended. Concise SentenceContrary to the current literature, weight loss in patients with late-diagnosed LCFAOD can be successful. A description of two FOAD patients who lost weight without encountering negative side effects at two academic centers is given.