There is limited prospective evidence at population scale of the impacts of lifestyle and surrogate measures of general and abdominal adiposity on the transition of a metabolically healthy (absence of a metabolic disorder) overweight/obese (MHOO) phenotype to a metabolically abnormal overweight/obese (MAOO) phenotype. Therefore, we determined the relationship between 10-year body mass index (BMI), waist circumferences (WC), waist to height ratio (WHtR), and lifestyle changes and the transition of the MHOO phenotype. We conducted a prospective population-based study of 3,052 male and female Spaniards aged 25-74 years who were followed from 2000 through 2009. Diet and leisure-time physical activity were recorded on validated questionnaires. Weight, height, WC, blood lipids, glycemia, and blood pressure were measured. All variables were obtained at baseline (BL) and follow-up (FL). Participants with a BMI ≥ 25 kg/m(2) and free from hypercholesterolemia, hypertriglyceridemia, diabetes, hypertension, and low HDL and high LDL cholesterol levels were characterized as the MHOO phenotype. A composite healthy lifestyle index (HLI) was constructed by including temporary changes in 3 lifestyle variables (diet, leisure-time physical activity, and smoking). Initially, 20.8% of subjects had the MHOO phenotype; 49.2% of these shifted to MAOO phenotype. In multivariate analysis, changes in BMI, WC, WHtR were positively associated (p = 0.004, p = 0.018, and p = 0.016, respectively) with this transition. One unit increase in the HLI was associated with a 33% lower risk (p = 0.025) to the MAOO phenotype transition after adjusting for age, sex, educational level, and baseline energy intake, BMI, WC, and WHtR. The presence of metabolic disorders in the MHOO phenotype is predicted by an increase in anthropometric surrogate measures of general and abdominal adiposity. In contrast, a healthy lifestyle protects against a transition to the MAOO phenotype.