The experts believe that , doing some activities immediately after eating food , is harmful for Digestion System . Also they say , Doing these things may cause Cancer . Maybe knowing these activities and following these implementation recommendations , causes to have a healthy body, 1. Don’t Drink ice water : Some experts say , Drinking ice water , After eating food , Causes Gastric Cancer . But this theory doesn’t have the right scientific basis . The only Difficulty may occure is stomach ache or intestinal muscles Contraction . The other point is that if you Drink water immediately after eating food , It causes the dilution of Gastric juice and it Can interfere with digestion . Then it’s better don’t drink water half an hour before and after eating food . 2- Don’t Smoke : The result of researches Show that smoking Can Make acidic the environment of the stomach . This Factor negatively affected the functioning of the stomach And prevents proper digestion of food . then it’s better not smoking half an hour before and after eating . 3-Don’t eat fruits : One of our bad habits , is eating fruit after eating food , But this is wrong . It’s better not eating fruit half an hour before and after eating food . Because eating fruits cause stomach bloating , of course eating cooked fruit (Such as canned fruit ) is alright . 4-Don’t take a bath : One of the public beliefs is that don’t taking a bath just after eating , and it is approximately right But it’s not for all peoples . The old people or whom which have progressive heart disease , Must not take bath half an hour after eating . 5-Don’t exercise : Exercising exposes pressure on the people whom suffer Cardiovascular disease . If you eat a light meal , You must avoid exercising or Physical Activity at least 2 or 3 hours and If you eat heavy meals You must avoid 3 or 4 hours . 6-Do not Walk much : Don’t walk long , at least half or an hour after eating . 7-Don’t Sleep : Don’t Sleep at least two hours after eating . So eating Dinner lately at night is very wrong . 8-Don’t Drink Tea : Tea of any kind (black , white and green ) contains substances called tannins . Tannin Compounds prevent the absorption of iron . So Drink Tea until one hour after eating . 9-Don’t Have marital relations : Heart patients pay attention to this consideration . Marital ralations causes a kind of stress to the cardiorascular system . In some rare cases , Doing this action after eating has caused heart attack , It’s better to refrain from marital relations the people with advanced heart disease or those who have recenly suffered A heart attack , Some hours after eating a meal .