I am 17 years old and I weigh 142lbs. I am 5 ft 1 in am I overwight I have a 6 month old baby

Check BMI . Use a BMI calculator to know. SEE: https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm. BMI Categories:
Underweight = <18.5 * Normal weight = 18.5–24.9 * Overweight = 25–29.9 * Obesity = BMI of 30 or greater. By checking your BMI you can get an idea of whether you are in a healthy range.
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Your . Your body mass index (bmi) calculates to 26.8. Overweight is 25- 29.9. By that criterion, yes, you are overweight (but not obese, which is defined as a bmi of above 30).