Relaxing for a while before and after a meal is good.
Walking straight up to a plate of food after a stressful or high energy activity can cause you to eat very quickly and aggressively. This makes the food hit your stomach with little salivary juices and a high acid content. If you are tense sort of person, some relaxation before a meal is good, so that your tensions don't interfere with digestion. Even just 5 minutes of closing your eyes, and focussing on your breath can be very beneficial. If there is a problem on your mind, try to alleviate it before eating, because after a meal, you will think less clearly. If I am in the middle of a difficult mental problem, I would rather fix the problem and eat 10 minutes later, than carry that problem to a meal, subconsciously dwell on it whilst I eat, then return to it again later.
Heavy exercising soon after a meal is not good, but then neither is slothing around
After a meal should be a time of taking it a bit easy. This doesn't mean a Mediterranean siesta of several hours! A period of sitting, an easy walk or light work for say 30 minutes is best. Lying down soon after a meal is a disaster. You just get up feeling more full and a real appetite may not return for several meals. The stomach works best if it is the highest point of the digestive system until it is empty, so being vertical is best.
Just as swimming straight after food is taught to be dangerous because the body can cramp up, heavy work or strong exercise within 30 minutes of a light meal or 1 hour of a heavy meal, is not advised either. The cycles of the breath, the stomach and the intestines, must be allowed to work efficiently upon the food for the first few hours or so. When the body starts digestion, blood and heat are drawn from the extremities primarily to the stomach. This is necessary for the chemical reactions upon certain nutrients. Only after the stomach is clear of food does the body free up this heat and some extra energy for further output. Disturbing the stomach's needs by diverting that heat and moisture outwards in the form of heavy work or sport, can cause any number of discomforts including cramps, headaches, indigestion and / or constipation.
Sleeping soon after a meal is not good
When asleep, the body does not digest fully from stomach to anus. The metabolic
rate is drastically reduced when sleeping, and the body will therefore switch off some of what it considers to be unnecessary functions. The hard work of the stomach's churning is not catered for when asleep. The middle stage, that is assimila-tion from the small intestines is allowed to work, as it helps in regenerating the body's cells lost during daily function. The bowels, or large intestines, are not supposed to work. That's why you should go to the toilet before bed to take away any tendency for a need to wake up in the night. Constipation is one of many causes of sleeplessness. In general, (depending on quantity and quality of food) leave at least 2 hours before sleeping on a meal. It is much better to go to sleep with a nearly hungry body than a well-filled one. The result of going to sleep with food still in the stomach is that bloated feeling upon waking up.
Snacking soon after a meal is not good
After the body has gone into digestion and assimilation mode, it is not good to give it anything more to work on again until the first few stages of digesting the previous meal are complete. Snacking within 2 hours will leave the stomach in a state of being continually switched on. Digestive acids and enzymes will cause ulceration and blood sugar levels will become unmanageable. Mature-onset diabetes can be caused by these kind of eating habits over the years. Snacking is caused by many psychological factors which have been mentioned before, and it is also caused by a shortage of slow release carbohydrates in the meals. It is these which give you stamina. When they are lacking, "snackers" go for lots of little sugar hits to top them up till the next meal. But just cutting out the snacks won't help. The whole diet and lifestyle equation needs to be reappraised.
Although you might not think so, drinking requires certain digestive processes. Drinking liquids, other than a little water necessary for the overall moisture in a meal, should be left until at least 30 minutes after a meal. Then the liquids can be absorbed without diluting the stomach acids. As stated previously, the body treats substantial liquids (those with strong tastes and nutrients like beer, wines, spirits, full strength fruit juices, milks, coffee, soft drinks) as if they were foods. Those kinds of "liquid foods" are not just water going into the blood stream. The body has to work on them a lot more than it does water.