Myths are obviously the fruit of partial or total ignorance, and speculations, handed down from generation to generation. While many of them are totally false, some of them are true or partly true. Here are eight of them:
1."Don't smoke after a meal because the bad effect (emphysema, cancer, etc.) of smoking a cigarette becomes ten times worse."
This is true in the sense that the natural bodily absorption rate following a meal is heightened, magnifying the ill-effects of tobacco (nicotine) on our system. One stick of cigarette, like one drop of any poison, is one too many.
2."Don't eat fruits immediately after a meal because this will cause the stomach to bloat with air. Therefore take fruit 1-2hours after meal or 1hour before meal"
This is not true. Fruits improve our digestion. However, there are people who have some degree of intolerance to fruits (fructose intolerance), who will have the sense of bloating after ingestion of fruits. In general, eating fruits right after a meal is good and well-tolerated by the body. Diabetics should discuss this with their physician since fruits will be additional calories that must be taken into account when computing their "diabetic diet."
3."Don't drink tea after a meal because tea is high in acid which will harden the protein content of food we consume thus make it difficult to digest."
It is true that tea is high in tannin or tannic acid, but the rest of the statement is false. Tea, as a matter of fact, improves our digestion. It is a tonic that invigorates the brain, speeds up the circulation, and makes the stomach digest food easier.
4."Don't loosen your belt after a meal because this will cause your intestines to twist and get blocked up."
The first part of the statement is a sound advice, but not for the reason given. Not loosening your belt after a meal makes you more conscious that your stomach is full enough, so you do not overeat. Also, the "normal tightness" of the belt provides one a natural "suck-in-the-abdomen technique" of controlling your waistline. It has been shown that sucking in the abdomen (as in the required military posture among cadets, etc) does help prevent "bulging waistlines," since sucking in the belly is nothing but an exercise to contract the muscles of the abdomen. If one does it every moment of awareness, which is like exercising the abdominal muscles every few minutes to make them taut and firm. The part about intestinal twisting and obstruction is false.
While taking a bath (especially a warm one) will divert some blood from the stomach to the skin, taking a bath after a meal will not significantly impair digestion. The general rule is: after a meal, do not to do strenuous activities that will divert a lot of the blood away from the stomach, which needs "enough" blood for digestion. What's enough for one person may be different from another individual's physiologic need.
Walking or strolling after a meal is not bad at all. It will help burn up some calories without significantly diverting blood from the stomach. Only strenuous physical and mental activities are discouraged immediately after a meal.
7."Don't sleep immediately after a meal because food will not be digested properly and this will lead to gastric infection."
The first part is true: it is not healthy to sleep with a full stomach. Not that it will cause "bangungot" or pancreatitis (as another myth claims), but gastric distention can lead to some heart irregularity in some people. Habitually sleeping immediately after a meal will also increase the tendency to obesity. As far as gastric infection is concerned, that claim is false.
8."Don't eat again until after four hours or longer because this will make the stomach stretch and grow larger."
This is not a myth but a sage advice. The stomach grows larger the more often we eat and the more food we eat, stretching our stomach, and conditioning our brain to crave for more food with every meal. And this will inevitably lead to obesity and its dangerous implications and complications. Drinking a tall glass, or two, of water before each meal will distend the stomach somewhat and "fool" the brain and curve the hunger sooner, leading to less total caloric intake. A simple, cheap and great dieting strategy.