No, it is not impossible to lose weight after 40 yrs, but yes, it is slightly difficult due to hormonal changes of pre-menopause
. Since you have been struggling with weight issues and
are not eating much, there is a chance you have problems like PCOD, diabetes, hypothyroidism or anemia, which are making it difficult for you to lose weight. Please get this investigated. Also, please consult a psychologist dealing with eating disorders.