Long-term weight maintenance after a low-carbohydrate diet: a real-world retrospective cohort study.

OBJECTIVES: Low-carbohydrate diet (LCD) promotes short-term weight loss in individuals with overweight or obesity, but long-term maintenance remains uncertain, particularly in real-world settings. This study aimed to identify predictors of weight regain following a short-term LCD intervention in a hospital-based weight management program. METHODS: This retrospective cohort study included adult individuals with overweight or obesity (BMI ≥ 24 kg/m²) who underwent an LCD between July 2016 and July 2020. Baseline anthropometric and metabolic data were extracted from medical records, and follow-up weight and lifestyle information were collected via structured telephone interviews and questionnaires at least 12 months post-intervention. Weight regain was defined as regaining ≥25% of initial weight loss. Multivariable logistic regression identified independent predictors of weight regain, adjusting for age, sex, and other confounders. RESULTS: Among 294 participants, all subjects received an LCD intervention for an average of 6.9 ± 4.2 weeks, and the average follow-up duration was 36.7 months. Of these, 153 (52%) regained weight, while 141 (48%) maintained weight loss. Despite a higher initial BMI (30.6 ± 5.3 vs. 29.1 ± 4.4 kg/m², p = 0.008), maintainers exhibited greater long-term stability. A family history of obesity significantly increased weight regain risk (OR = 2.36-2.84, p < 0.01), whereas adequate sleep (6-8 h/night) was protective (OR = 0.15-0.16, p < 0.05). LCD duration, initial weight loss, and exercise frequency were not consistently associated with maintenance. CONCLUSION: Both genetic predisposition and lifestyle factors influence long-term weight outcomes, underscoring the interplay between immutable and modifiable determinants in weight management.