s carbohydrates, fats, and proteins, are the basis of all life activities. They constitute the carbon skeleton of various functional molecules, and provide energy through oxidative decomposition. Traditionally, the main aim of nutrition is prevent and treat nutritional deficiencies.
However, when nutrition is adequate or excessive, the body faces the problems of quantitative control of the nutrients absorption and storage. Over nutrition, especially absorption and storage of energy, can not only affect health but also cause many diseases such as diabetes, cardiovascular diseases, obesity, hypertension, and hyperlipidemia.
Further, over nutrition reduces reproductive capacity and promotes the development of various cancers that will seriously affect quality of life, survival, and reproduction in human beings. Because of over nutrition, nutriology based on nutritional requirements cannot make recommendations for nutrient intake in daily life because nutrient absorption, energy storage, and oxidative energy supply control vary from person to person.
Even during evolution, nutritional experience seems to be recorded in the nucleosomes and DNA, which involves all aspects of nutrient sensing, cell communication, metabolic regulation, gene expression, and epigenetic modifications. However, food intake is a fundamental activity of the human body and is a source of energy.
Modern diet relates to ‘Junk food’ that simply means an empty calorie food. An empty calorie food is a high calorie or calorie rich food which lacks in micronutrients such as carbohydrates, proteins, vitamins, minerals, or amino acids, and fiber but has high energy (calories).These foods does not contain the nutrients that your body needs to stay healthy. Hence, this food that has poor dietetic values is considered unhealthy and may be called as junk food.
Junk food is an informal term applied to some foods which are perceived to have little or no nutritional value, but which also have ingredients considered unhealthy when eaten regularly, or to those considered unhealthy to consume at all.
The term junk food was coined as slang in the public interest in 1972 by Michael Jacobson, Director of the Center for Science, Washington DC. What makes these foods to be called as Junk is that it contains high levels of refined sugar, white flour, trans fat and polyunsaturated fat, salt, and numerous food additives such as monosodium glutamate and tartrazine at the same time it is lacking in proteins, vitamins, essential minerals, fiber, among other healthy attributes.
These foods have little enzyme producing vitamins and minerals and but contain high level of calories in their place. A food that is high in fat, sodium, and sugar and provides high calories yet useless in value is generally known as a junk food which the present generation has adapted it as modern diet.
On the contrary, junk food is easy to carry, purchase and consume . Generally, a modern diet is given a very attractive appearance by adding food additives and colors to enhance flavor, texture and for increasing long shelf life.
Recent variations and trends in food, nutrition, physical activity, overweight and obesity. People’s diets reflect the times and situations in which they live. It is only relatively recent in history that urban– industrial ways of life have evolved, with many or most people living in towns and cities rather than in the countryside.
In much of Asian and African countries most people still live in rural communities, and farmworker-agricultural and urban-industrial ways of life still coexist in most countries. Such patterns change very rapidly as countries become increasingly urbanized and industrialized. The different food systems and diets that are part of these diverse ways of life affecting people’s levels of physical activity, their body composition and physique, their life expectancy, and patterns of disease, including cancer.
With the move to urban–industrial ways of life, populations have become taller and heavier, their life expectancy has increased, and they are usually adequa