If you became thin now only, or suddenly you noticed it, then you need to go for check ups like blood, hb levels, thyroid levels, etc better to go for check ups under advise of any near by doctor. If nothing wrong, then its purely due to less intake of food r less nutritious food r more stress
, lack of sleep etc. Based on all these, you need to evaluate n take care in that aspect. For time being, you can try alfalfa malt syrup twice/day&five phos 6x tablets daily. 5-5. For 2 months. Provided with good intake of food n practice any exercises&meditation.