Underweight
A BMI under 18.5 can mean you're carrying less weight than is healthy for your height. Sometimes that's natural build; sometimes it points to under-nutrition, a thyroid issue, or another underlying cause worth checking.
What to do next Focus on nutrient-dense Indian meals — dal, paneer, nuts, ghee, whole grains — rather than empty calories. If weight loss was unintentional, see a doctor to rule out a cause.