Hi, welcome to H.C.M.Forum, you have to visit a fertility
clinic for this purpose. 40% is not a big problem. fault may be in either of you, for that screening of both of you should be done.for stomach he should avoid fatty foods, junk foods, fleshy fruits. minimise the sleeping time, avoid afternoon sleep. he should eat proteine rich food , green leafy vegetables, juicy fruits and juices. thank you.