Thank you for seeking my advice. The causes for decreased sexual desire and arousal in your wife may be due to less production of Estrogen or it may be a case of psychologically embedded reason, or it may be at the worst being unable to reach orgasm after enduring sexual intimacy. To tide over the situation I would suggest your wife to have food that has low contents of sugar and carbohydrates e.g. soybeans, legumes, fruits and vegetables. Convince your partner to have light to medium exercises to increase the secretion of Estrogen and eat flax seeds which contains omega 3 and fatty acids. Fresh organic food may be the right diet for your wife to overcome this problem. Wish you a happy sexual life.