In youths, two cut-offs (133 and 155 mg/dL) have been proposed to identify high glucose levels at the 1 h (G60) mark during an oral glucose tolerance test (OGTT). We evaluated which cut-off was more closely associated with isolated impaired glucose tolerance (IGT) and cardiometabolic risk (CMR) in 1199 youth with overweight/obesity (OW/OB) and normal fasting glucose and/or HbA1c. The disposition index (DI) was available in 724 youths. The sample was divided by two cut-offs of G60: <133 mg/dL (n = 853) and ≥133 mg/dL (n = 346), or G60< 155 mg/dL (n = 1050) and ≥155 mg/dL (n = 149). Independent of the cut-off, youths with high levels of G60showed higher levels of G120, insulin resistance (IR), triglycerides to HDL ratio (TG/HDL), alanine aminotransferase (ALT), and lower insulin sensitivity (IS) and DI than youths with lower levels of G60. The percentage of youths showing IGT, IR, low IS, high TG/HDL ratio, high ALT, and low DI was 50% higher in the G60≥ 133 mg/dL group than in the G60≥ 155 mg/dL one. In youths with OW/OB and IGT, a cut-off of G60≥ 133 mg/dL is more useful than G60≥ 155 mg/dL to identify those at high risk of IGT and altered CMR profile.