Ten-year medication-free remission of type 2 diabetes in a South Asian male using a culturally adapted low-carbohydrate diet: an N-of-1 longitudinal study

Background T2D mellitus (T2DM) is increasingly prevalent in South Asia, often affecting individuals with normal BMI, a phenotype described as metabolically obese but normal weight (MONW). While randomized trials demonstrate that low-carbohydrate diets can induce remission, long-term, real-world evidence in non-obese, predominantly vegetarian South Asian populations remains scarce. Objective To evaluate the long-term efficacy and safety of a culturally adapted low-carbohydrate diet in an N-of-1 longitudinal study with systematic, multi-domain follow-up. Methods A 49-year-old male with new-onset T2D (HbA1c 7.2%) began a phased initiation (~100 g/day carbohydrate), nutritional ketosis (<30 g/day carbohydrate), and long-term stabilization (~100 g/day). Assessments included continuous glucose monitoring (CGM) periodically, standardized mixed-meal challenges, advanced lipid and apolipoprotein panels including ApoB and lipoprotein(a) [Lp(a)], hs-CRP, liver and renal function, and serial cardiovascular, skeletal, and ophthalmic imaging over 10-years. The study was monitored through regular physician assessments and follow-up. Results HbA1c remained between 4.7 and 5.3% without medication for a decade. CGM showed >90% time-in-range with reduced variability (CV decreased from approximately 18–12%), Lp(a) decreased (43.4 → 25.3 mg/dL), and hs-CRP remained <1 mg/L. Coronary artery calcium (CAC) remained 0 across three scans, with CT angiography confirming CAD-RADS 0. CIMT showed no stenosis. Bone mineral density and ophthalmic imaging showed no deterioration. Conclusion This report offers a detailed N-of-1 longitudinal characterization of decade-long, medication-free remission of T2D in a metabolically obese normal weight South Asian male. Observations at approximately 100 g per day carbohydrate intake suggest that moderate carbohydrate restriction may represent a physiologically plausible and culturally compatible approach for long-term metabolic management in similar phenotypes. While broader applicability requires validation in larger cohorts, these findings provide a rationale for further evaluation of moderate carbohydrate restriction as a feasible dietary strategy in South Asian and comparable settings.