From an Islamic perspective health is viewed as one of the greatest blessings that Allah has bestowed on mankind.

From an Islamic perspective health is viewed as one of the greatest blessings that Allah has bestowed on mankind. It should be noted that the greatest blessing after belief is health, as narrated in the following Hadith:

The final messenger of Allah (God), Prophet Muhammad (pbuh) mounted the pulpit, then wept and said, "Ask Allah (swt) for forgiveness and health, for after being granted certainty, one is given nothing better than health." 
Related in Tirmidhi 

Health is indeed a favour that we take for granted. We should express gratitude to Allah for bestowing us with health, and we should try are up most to look after it. Allah has entrusted us with our bodies for a predestined period of time. He will hold us to account on how we looked after and utilised our bodies and good health.

It has been narrated that Prophet Muhammad (pbuh) said:

"No one will be allowed to move from his position on the Day of Judgement until he has been asked how he spent his life, how he used his knowledge, how he earned and spent his money and in what pursuits he used his health" 
Related in Tirmidhi 

The preservation of this blessing can only be achieved through taking good care of one’s health and taking every measure to maintain and enhance it. With this in mind every Muslim should make sure they undertake all necessary actions which are conducive to the preservation of good health. Healthy living is part and parcel of Islam, introduced with the inception of Islam more than 14 centuries ago. Furthermore, the Quran and the Sunnah outline the teachings that show every Muslim how to protect his health and live life in a state of purity. Numerous examples in Islam instruct its followers to live a healthy life, a selection are summarised below.

Daily prayer

Any health benefits derived from prayer or any other worship (fasting) are secondary in importance. The Salah or Islamic prayer comprises both physical movement and mental concentration. Performed five times a day at specific times of the day, the obligatory prayers provide a good means for the circulation of blood, breathing and general suppleness of joints. Though it is not physically over demanding, we know that anything done moderately and consistently is far better than sudden over-exertion at infrequent periods.

Ablution before Prayer & Ghusl 

Before a Muslim performs their prayers, they must perform the ablution which comprises thorough washing of the hands, mouth, nose, face, arms (up to the elbow) and the feet (up to the ankle). This ritual of self-purification when carried out five-times a day, leaves the worshiper clean, refreshed and ready to face his creator. Muslims are also required to clean themselves with water after urinating or defecating. Another act of worship which also helps to maintain good health is taking a shower, or ghusl. This is compulsory when one is in the state of ritual impurity, and is compulsory at least once a week before attending the weekly Friday prayer.

Diet & Nutrition 
Various verses and texts within Islam promote the eating of healthy wholesome food and eating in moderation. God clearly states in the Quran:

Eat of the good things which We have provided for you. (2:173) Eat of what is lawful and wholesome on the earth.(2:168)

A healthy nutritious diet must also be balanced, in order to maintain the balance that Allah has established in all things, this is addressed in the Quran when Allah says:

And He enforced the balance. That you exceed not the bounds; but observe the balance strictly; and fall not short thereof. (55:7–9) 

As we know, eating excessively causes harm to our systems. Many aliments are related to uncontrolled eating habits such as, diabetes, vascular diseases, stroke, heart attack etc. It has been said that the ‘stomach is the home of ill health’ and is usually responsible in some way to ill health. Islam teaches us to eat moderately:

Eat and drink, but avoid excess. (20:81) 

Over indulgence and wasting of food are further dissuaded in the Hadith of the of the Messenger of Allah:

‘ No human being has ever filled a container worse than his own stomach. The son of Adam needs no more than a few morsels of food to keep up his strength, doing so he should consider that a third of his stomach is for food, a third for drink and a third for breathing’ 
Ibn Maja 

Fasting 
Fasting during the month of Ramadan from dawn till dusk, is undertaken to seek the pleasure of Allah and to practise self control and restraint in all aspects of living, with the idea being to continue this state of Allah consciousness and piety after Ramadan is over. It is an ideal time to remove the impurities and shortcomings in ones life.

‘ O you who believe fasting is prescribed to you as it was prescribed to those before you so that you can learn 
Taqwa (Allah consciousness)’ 

Fasting in Islam is not like crash dieting, it is adequate in calorie intake and involves no malnutrition. All foods are permissible to eat in moderation, once the fast is over. Many processed foods we eat contain chemicals which over-time can be stored by our bodies as toxins within cells. Fasting can assist our body to purge these toxins while also allowing our body and digestive system to rest. Research has indicated that fasting can lower blood sugar levels and cholesterol, suggesting it may be advisable for moderate, stable, non-insulin diabetes, obesity and essential hypertension.

Prohibition of Intoxicants 

Islam strictly forbids indulgence in intoxicants such as alcohol and drugs for good reason. The limited pleasure of such vices causes immense long-term damage to both mind, body and the social fabric of society. Particular schools of thought include smoking within the list of prohibitions because of its harmful affects on the body. It seems that if Muslims adhere to the teachings of Islam, they would automatically lead a healthier lifestyle. Allah says in the Quran:

Satan's plan is (but) to excite enmity and hatred between you with intoxicants and gambling and hinder you from the remembrance of Allah and from prayer, will ye not then abstain? (5:90)
 

-muslimhealthnetwork.org