Food is essential for human survival as it provides the basic energy and nutrients for all cells in the body for proper growth and body development. The life cycle of a human being begins with birth, growth, development, reproduction and eventually death. Sack  suggested that food is ephemeral in nature and it reflects human dependence on the divine, is transitory and yet essential. When food is associated with religion, it reflects the culture and the unique identity of the person, in short summarizing the quote: "You are what you eat" .
Geissler  pointed that food serves as a constant reminder of what we believe and in contrary to ethical considerations, which operate primarily on an individual, religious food rules serve not only to enhance the spiritual life of the individual but also to enhance allegiance to a community of believers. But are these foods nutritious enough for a person to be healthy throughout his life? From the religious context, besides the importance of wholesomeness of a food, Islam stresses the primary requirement on its halal status.
The fact that the increasing trend of chronic diseases, such as cardiovascular diseases, stroke, cancer, chronic respiratory diseases and diabetes, which are the leading causes of mortality in the world today warrants urgent address of what went wrong with our diet in the past? Records from the World Health Organization in Figure 1 shows that of the 56.4 million deaths worldwide in 2015, more than half (54%) were due to the top 10 causes. Ischaemic heart disease and stroke are the world's biggest killers, accounting for a combined 15 million deaths in 2015. These diseases have remained the leading causes of death globally in the last 15 years.
Chronic obstructive pulmonary disease claimed 3.2 million lives in 2015, while lung cancer (along with trachea and bronchus cancers) caused 1.7 million deaths. Diabetes killed 1.6 million people in 2015, up from less than 1 million in 2000. Deaths due to dementias more than doubled between 2000 and 2015, making it the 7th leading cause of global deaths in 2015.
Lower respiratory infections remained the most deadly communicable disease, causing 3.2 million deaths worldwide in 2015. The death rate from diarrhoeal diseases almost halved between 2000 and 2015, but still caused 1.4 million deaths in 2015. Similarly, tuberculosis killed fewer people during the same period, but is still among the top 10 causes with a death toll of 1.4 million. HIV/AIDS is no longer among the world's top 10 causes of death, having killed 1.1 million people in 2015 compared with 1.5 million in 2000. (Source: WHO, 2017)
Chronic diseases are largely preventable diseases involving diet and nutrition, which is important, factors in the promotion and maintenance of good health throughout a person’s life. Besides prescribing the appropriate medical treatment for those already affected, the public health approach of primary prevention is considered to be the most cost-effective, affordable and sustainable course of action to cope with the chronic disease epidemic worldwide. The adoption of a basic diet such as Halal diet to prevent chronic diseases would be highly welcomed to curb modern dietary patterns which are high risks affecting the disease patterns globally.
While age, sex and genetic susceptibility are non-modifiable; many of the risks associated with age and sex are modifiable. Such risks include behavioural factors such as diet, physical inactivity, tobacco use and alcohol consumption; biological factors (e.g. dyslipidemia, hypertension, overweight, hyperinsulinaemia); and finally societal factors, which include a complex mixture of interacting socioeconomic, cultural and other environmental parameters.
Diet has been known for many years to play a key role as a risk factor for chronic diseases. What is apparent at the global level is that great changes have swept the entire world since the second half of the twentieth century, inducing major modifications in diet, first in industrial regions and more recently in developing countries. Traditional, largely plant-based diets have been swiftly replaced by high-fat, energy-dense diets with a substantial content of animal-based foods. But diet, while critical to prevention, is just one risk factor. Physical inactivity, now recognized as an increasingly important determinant of health, is the result of a progressive shift of lifestyle towards more sedentary patterns, in developing countries as much as in industrialized ones .
The preservation of future generation and the protection of consumer health is a priority in view of the incremental negative phenomena existing in societies at large. It is also necessary to re-examine seriously the basics of life itself whereby every human needs food to survive and how does this affect his health and wellbeing. Is it not the quotation "You are what you eat" means more?
The Islamic way of life is a system of Divine principles and code of ethics to be applied in the daily life of every person. Every deed is a form of worship and eating is one of them and it has to be based on the Islamic laws. In perspective, Muslims should eat sufficient amount of food, as stated in the Quran (7:31).
"O children of Adam, take your adornment at every mosque, and eat and drink, but be not excessive. Indeed, He likes not those who commit excess."
In any environment, a human being is considered healthy if he is not sick, physically and mentally. What about his spiritual life, his inner self? Hence, Halal Nutrition is the answer, which will be highlighting two key elements: the halal food (Prophet Muhammad s.a.w. diet) and the Islamic eating practices of the Prophet Muhammad s.a.w. These two important elements form a strong foundation for "Shariah Maqasid" (objectives of the Islamic law) in protection and preservation of the five essential elements of a human being. These elements are life itself, intellect, religion, lineage and property. The motives behind the concept of consuming halal food and drinks, and therefore abstaining from haram products are very specific, namely:
To preserve the purity of religion;
i. To safeguard the Islamic mentality;
ii. To preserve life;
iii. To safeguard property;
iv. To safeguard future generations; and
Shariah (Islamic law) means the commands given by Allah to His servants, which has been brought by any of the prophets. It constructs human life on the basis of virtues (ma'rufat or good qualities/values) and to cleanse human life of vices (munkarat or sins/evils). The Shariah is generally aimed towards predicating on the interests (maslahah) of the individuals and the community (Kamali, H. 2000). Shariah laws are designed so as to protect these interests and facilitate improvement of human life on earth by preventing injustices, corruption and eliminating hardships, thereby promoting these benefits to mankind. This shows that the objective of Islamic law is not only contributing to the growth of Islamic civilization but also in the preservation of health or preventive medicine .
The Qur'an, as the only guiding document to all Muslims has clearly mentioned the halal (permissible) and haram (impermissible) foods to be consumed by mankind, has also provided us with useful tips regarding a balanced diet: a diet which contains most, if not all the useful ingredients required for the growth, strengthening and repairing of the human body. These ingredients include animal protein, fat, carbohydrate, minerals and vitamins in the form of meat, fish, fresh milk, grains, fruit and vegetable [6-11].
The Sunnah has also teaches us on the ethics of eating in Islam. We are advised to be moderate in eating and drinking as the Prophet Muhammad s.a.w. has clarified the meaning and limit of moderation in eating in which he is reported to have said that one’s worst weakness is one's stomach. If you must eat make sure you fill one third of your stomach with food, one third with water and leave one third for air. In short, we are advised to always take care of our stomachs and refrain from eating too much food that might contaminate the stomach with various pathogens which can results in diseases.
The other very important habit of the Prophet Muhammad s.a.w. is to stop eating before the stomachs are completely full i.e. stop eating when the urge to eat more is still present. The emphasis here is the prohibition of over eating as stated in the following Hadith:
"It is enough to eat few morsels of food to keep one’s back straight."
"A Muslim eats in one intestine (stomach) whereas a non believer eats in seven intestines."
There are other ethics or manners in eating which the Prohet Muhammad s.a.w. has taught us. This include washing hands before and after eating, to start eating with the praise of Allah, to eat using the right hand, not to eat until one feels hungry, not to eat and drink excessively and finally, praise and thank Allah for the food and drink we consume and for making it easy for us to swallow and for producing an exit for it.