Appropriate dietary intake and physical activity (PA) are essential for glycemic control and optimal growth in youth with type 1 diabetes (T1D). Thus, this study aimed to compare dietary intake and PA between youth with T1D and healthy controls. One hundred Thai youth with T1D and 100 age-matched healthy participants were recruited. A 3-day food record was completed and converted into nutrient intake data. PA data were collected via interview. Participants with T1D had a significantly higher mean ± SD carbohydrate (50.8 ± 6.8% vs. 46.2 ± 7.5%, p < 0.01), lower fat (32.4 ± 5.9% vs. 35.9 ± 6.4%, p < 0.01), and lower protein (16.8 ± 2.6% vs. 17.9 ± 3.5%, p = 0.01) intake compared to controls. Fifty percent of T1D participants and 41% of control participants consumed saturated fat more than recommendations (p = 0.20). Participants with T1D had a higher median (IQR) calcium intake compared to controls (474 (297–700) vs. 328 (167–447) mg/day, p < 0.01). Both groups consumed less fiber and more sodium compared to recommendations. Both groups had inadequate PA. Participants with T1D had significantly less PA compared to controls (25 (13–48) vs. 34 (14–77) minutes/day, p = 0.04). In addition to the need for counseling that promotes consumption of more dietary fiber and calcium and less saturated fat and sodium, the benefits of performing regular exercise need to be emphasized among youth with T1D.