Eat to live, don't live to eat.
Sounds a wee bit trite but it sticks; when I make a conscious effort to bring awareness into my body with the food I consume to sustain it, I will get more out of what is sustaining me. It helps to picture the food as wholesome and nourishing, and if I can see the true purpose of the food is to strengthen me in my ongoing practice of yoga (as in union with the ultimate reality, not asana), the likelihood of reducing food to a mere sensual gratification is diminished.
Never eat over half the stomach's capacity.
This might be easy when at home in a regular routine, but try and follow this one visiting family over the holidays. Still, the more we can reserve a quarter of stomach capacity (metrics don't need to be exact, obviously) for liquid, and leave a quarter empty, the better.
Chew food well and taste it well.
If we give ourselves time to savour the food, chewing slows down and the stomach can process it fully, getting the most out of the nutrients that are available within. Poor chewing creates malabsorption disorder; focus on the experience and enjoyment of the food. Taste commands the stomach what enzymes need to be released. The slower we chew, the more time the enzymes in the stomach have to prepare for what is being swallowed. The more we chew with awareness and enjoyment, the better the food will be absorbed and serve our purposes.
Avoid eating too many different foods in one meal.
Eating too many varied foods at the same time can lead to enzymatic overload and malabsorption.
Eat vegetarian meals as much as possible
Vegetarianism is preferred for both health and moral reasons; one only need visit a feed lot or a modern slaughter house to be convinced that eating meat is a moral issue. Non-vegetarian food is hard to digest, and the adrenaline in butchered animals, when taken into the human system creates and promotes stress, particularly when consuming animals which lived in abnormal conditions on modern farms and were slaughtered using modern techniques. Sometimes giving up meat entirely is very difficult for some people; it’s better to start slowly, decreasing meat intake gradually, and let it fall away on its own without getting self-critical (or critical of others - eating meat is probably better for you than being vegetarian and critical of meat-eaters). If one is going to eat meat, it should be free-range and organic as much as possible as well as Halal, where the blood is drained from the animal in such a way that reduces the effects of adrenal secretions into the tissue. The closer one is to a vegetarian diet, the shorter and more stress-free their digestive process will be. I am not a strict vegetarian, but the closer I am to a vegetarian diet, the better I feel.
Give the body time to digest properly.
Stomach should have at least 3 hours between meals to digest.
Constitution of meals.
Meals should consist mainly of vegetables with perhaps a small amount of grains and a small amount of protein. If eating grains, limit intake of gluten and try to eat whole grains with your breakfast (it is good to start with fruit and/or a smoothie and wait 20-30 minutes before ingesting anything else). Make lunch your largest meal, and dinner your lightest.
Cold beverages should be avoided as they shock the digestive system and put unnecessary stress on it. Don't dilute the enzymes in the stomach by taking in too much liquid before, during, or after a meal. Liquids should be taken 30 minutes before or 2.5 hours after a meal.
Most oil is hot pressed, and difficult to digest. Use cold-pressed oils for cooking and salads. When cooking with oil, don’t let it get so hot that it smokes.
What to avoid.
Avoid white rice, white bread, white sugar, caffeine, nicotine, alcohol and tannin as much as possible.
Increase intestinal flora with yogurt, ghee, probiotics.
Favour alkaline foods.
The mucous glands in the stomach are there to reduce the impact of hydrochloric acid in the stomach lining/walls. The hydrochloric acid is there to minimize the living organisms we take in which can infect us. Overly acidic or spicy foods can remove or thin the mucous and subsequently lead to peptic or gastric ulcer. Our food should be more alkaline than acidic. Some examples of alkaline foods: fresh meat, whole grains (bread should be eaten toasted), green, leafy vegetables. Even though citrus fruits are acidic, they actually promote alkalinity in the body.
A bowel movement is the best way to start the day for physical, mental and emotional purity, followed by clearing the nasal passages with neti pot, gargling with sea-salt water, pranayama (breathing exercises) and some asana practice. If constipated, this can lead to malabsorption and toxins leached into the body, which can pool in the synovial fluid, causing swelling of the joints (arthritis). Recommended is an ayurvedic sesame oil enema and to supplement diet with psyllium husk. Drinking several warm glasses of water first thing in the morning prior to getting up and moving about (this can be done by keeping a thermos of warm water by the bed), the duodenum valve below the stomach is relaxed and water can directly enter the intestine, causing a colon reflex. If you get up and make bodily movements before drinking the warm water, the duodenum valve closes and water stays in the stomach for some time before entering the intestines. While some sources cite lemon water as a remedy for constipation, constipated people who are primarily vata should not take lemon with their water. Lemon water loosens up phlegm, disturbs parasites and washes them out; it also alkalizes the digestive tract. But someone whose dosha is primarily vata should not take lemon because too much phlegm can be removed resulting in excess water absorption and, ultimately, greater constipation.
Cultivate greater global awareness of nutrition.
An awareness of the food we take in should exist throughout the entire digestion process. Most diseases and illnesses are a direct result of improper eating habits. The high levels of obesity, diabetes and cancer in the West are predominantly diet related and can be corrected through diet. With a poor diet, neurotransmitters are changed and immunity reduces, information pathways can fade, leading to lack of concentration which subsequently leads to an unfulfilling life. But this information is hidden in plain sight, and the quality of modern-day thinking has, on a large scale, deteriorated to the point of malaise and acedia, and often many people seem caught in the illusory world of manufactured popular entertainment, which frequently brings disease to the mind and promotes self-centeredness and seeds fear.
With respect to medication, a seeker has to guard against his/her own doctor becoming his pusher. For this reason, basic Ayurvedic concepts and fundamental principles of healthy diet would go a long way to promoting waste removal and rejuvenation of basic health (and consequently promote a reawakening in mental health).
All things are to be done in moderation, including changes to diet. The basic rule is start small but be consistent with the changes that are being absorbed. Experience everything as an observer, without reacting to it, even in your own body.
Be grateful for the food that nourishes your precious body, and cultivate awareness of where that food came from, how it was grown, and the solar energy and manual labour that brought it to your plate. If I have gratitude for what I am eating, as well as gratitude for the miracle that is my body, the likelihood that I will over-indulge is diminished.