Tip for Good Health, Religion
We've all heard of the "French Paradox", or why the French dont get fat despite the foods that they eat. There are many explanations like the amounts of coffee that they drink, cigarettes that they smoke, and the resveratrol in the wine that they drink. But another very important reason is the way they eat their food. The French believe that one must sit down and focus on their meals (not eat while watching tv, for example), and to eat very slowly. They say to spend at least 20 minutes on each meal, to savour every bite, and chew very slowly. This, I believe is one of the most important reasons that the french dont get fat.
I started doing this a month ago and it truly makes a huge difference. I eat very slowly, chewing my food as much as I can. In fact, when I'm eating I'm not thinking about the French and their way of eating but the Tibetans. Everytime I eat, I go by this Tibetan saying, "Drink your food and chew your water." Paul Chek elaborates,
That means you should chew your food until it's a liquid, and when you drink a liquid you shouldn't just slam it. You should move it around your mouth as though it was food because that mixes saliva with the water.
The saliva carries the energy from the spleen so it adds chi to the water; it enlivens the water so it'll actually have a therapeutic effect on the body. If you just slam piles of water straight into your stomach it's actually very stressful on the body. 
It is like the Prophet (pbuh) said about drinking: "Do not drink water in one breath like a camel. Recite the Name of God, breathe in and out to take three sips, and thank God." 
Well, I also think about the French when I eat in that my meal time is for eating only. Two days ago I was in the middle of Kurosawa's Seven Samurai when my dinner arrived. At first I was tempted to eat while watching the movie, but decided that it would cause me to be unconscious of my food and would make me swallow my food before chewing it properly. We have to be mindful of our eating in Islam, and in Zen Buddhism they consider this an important practice that novices must master, which they call Mindful Eating . So, I paused the movie, ate slowly, and when I was done I resumed the movie.
And like the Tibetan saying, evertime I eat I try to chew until my food is almost a liquid. This is great for many reasons. First, it improves digestion. When you don't chew your food enough, it is not digested as well because it is not exposed to the digestive enzymes in your saliva, and also because the chunks that go down are so big that they are not digested well by the stomach and intestines. This means that your body will not feel so good after eating, and it might make it more difficult for you to do your religious duties like prayer. That is why Muslims prefer to eat very little and to chew slowly, so that they always feel light and can perform all their prayers easily.
Also because of this greater digestion, you get more out of your food. When you do not digest your food as well, you do not get as many nutrients from it. Because of this, you need to eat larger quantities to get a sufficient amount of nutrients. By chewing very carefully, you get more nutrients from a lesser amount of food.
This brings us to the third benefit: eating less. By chewing more, you eat less. The longer you chew, the less food that you eat before you feel full. So you are getting all the nutrients that you need from less food, you are getting thinner, and your body feels much better the whole day, allowing you to perform your religious duties easier. All this by chewing slowly and carefully.
Finally, it helps if your food is not hot. I've come to like all my food cold. Today I made the mistake of eating food straight out of the oven and I was so shocked at the amount that I ate. When the food is really hot, it's very hard to keep it in your mouth long and to chew it, and so you just swallow it down without chewing on in. This means you will need far more food before you feel satisfied. I think I ate triple what I usually eat for lunch simply because the food was hot. Cold food allows you to chew it as long as you want, and to enjoy the taste. When it's hot, you don't feel the taste as much (or so it is with me). It doesn't have to be cold cold, just not hot. Personally, I like to eat all my food actually cold, like after taking out of the fridge. You don't have to do that if you dont like it (although I find it tastes better that way), just make sure it is not very hot, so that you can eat it at a slower rate. The colder the food, the less you need to eat before you are full. In fact, one of the most famous Islamic teachings about food is never to blow on hot food so that one could eat it, but to wait for it to cool down.
Also, the Messenger of Allah (pbuh) has said,
"Leave the food to cool for hot food has no blessing." 
And it is reported that he, peace and blessings be upon him, said,
"Eat cold food, because it has the blessing of abundance. If you are heedful you will see how much more you must eat when you eat warm food..." 
Anyway, just try not to eat your food when it's hot (warm is good enough), and eat very slowly. It will have more blessings and abundance, and your body will thank you!
For Sufi works about the proper way to eat see Book XI of al-Ghazali's Revival of the Religious Sciences, entitled Manners Relating to Eating or Alaa' ad-Dawla as-Simnani's Aadaab as-Sufra (Table Manners).
1. Wyatt, Caroline. "Aged 11, I was too big for Paris"
2. T-Nation: "Deconstructing Paul Chek"
3. Reported by Tirmidhi
4. Reported by Tabarani. This Hadith is further supported by a Hadith graded as Sahih (authentic) by Imaam Hibbaan which is as follows: When Sayyidatuna Asmaa bint Abu Bakr (Radhiallaahu Anhuma) used to cook Thareed (a special type of food), she used to cover it a while till the steam stopped, then she used to say, ‘I heard Nabi (Sallallaahu Alayhi Wasallam) saying, ‘Verily it is greater in blessing.’ (Saheeh ibn Hibbaan vol.7 pg.321)
5. Imam Birgivi. The Path of Muhammad, pg 16.
6. I added this paragraph after reading DA's comment to the post.