The progress of modern civilization in developed as well as in developing countries, although, has resulted in decline in infectious diseases in the last 50-60 years, but during this period, there has been a significant increase in chronic non-communicable diseases (NCDs). Nutrition and lifestyle changes, including altered dietary habits, stress and exposure to chemical carcinogens, are the major factors, thought to influence the susceptibility to many diseases, such as type2 diabetes mellitus (T2DM), hypertension, cardiovascular diseases (CVD) and certain types of cancer, termed as ‘Lifestyle disorders'. Within a generation in the last few decades there has been a rapid emergence of obesity and diabetes in all parts of the world. Obesity and other metabolic disorders such as insulin resistance type2 diabetes and cardiovascular diseases are closely associated with a low-grade inflammatory state. These diseases are no longer confined to the developed world. As millions of people in developing countries are also adopting a westernized lifestyle and are being affected by these diseases. The global annual medical cost of treating serious consequences of obesity is expected to reach US $ 1.2 trillion per year by 2025.

According to a recent study, besides child and adolescent obesity, globally, more children remain moderately or severely underweight than obese, with 75 million girls and 117 million boys moderately or severely underweight in 2016. Almost two-thirds of the world's children and adolescents who are moderately or severely underweight live in south Asia. Rise in child as well as adolescent obesity rates in low and middle income countries, especially in east, south and Southeast Asia, has accelerated. Whereas, it has plateaued, albeit at high levels, in many high-income countries since around 2000. Cheap, ultra-processed, calorie dense and nutrient poor foods contribute to obesity. In fact a good number of countries face a twin challenge of under-nutrition and under-weight, along with an alarming obesity. While excessive weight gain in childhood and adolescence is associated with a higher risk and earlier onset of chronic diseases such as type2 diabetes, at the other extreme, being underweight has its own share of health problems.

Both obesity as well as malnutrition increase risk for death, of course due to different causes. The former causes heart disease, diabetes and cancers, and latter contribute towards, infections such as tuberculosis, Pneumonia and multiple deficiencies. Both sometimes co-exist in many communities. Many malnourished women become pregnant and give birth to underweight babies. These are overfed in childhood, and later have early-onset of diabetes and hypertension. Thus there is a linear association between under nutrition, and early onset of diabetes and heart disease, linked with childhood over nutrition. It is expected that within the next few years the number of overweight children might exceed the number of undernourished children. It, therefore, becomes imperative to tackle under nutrition while also tackling obesity.

The health impact of eating a healthful diet and being physically active cannot be underestimated. Good nutrition, physical activity and a healthy body weight are key to a person's overall health and well-being. Together, these can help decrease a person's risk of developing serious health conditions, such as hypertension, elevated cholesterol levels, type 2 diabetes, cardiovascular diseases, stroke and even cancer. Several studies suggested that good nutrition throughout adulthood improves the likelihood of enjoying better physical fitness later in life. Making good dietary choices throughout adulthood i.e. by cutting down on highly processed foods and incorporating more fruits, vegetables and whole grains into one's diet, can have a significant beneficial effect on strength and physical performance later in life, helping to ensure a much healthier old age. Nutritionists can rattle off a long list of reasons when asked why is it so important to eat more veggies? Vegetables and fruits are dense in nutrients but light on calories. They contain rich amounts of vitamins, minerals, antioxidants and fiber. Dietary intake of more veggies and fruits has been linked to decreased risk for several such chronic health problems including cancer.

Fatty acids are the most energy-dense nutrients in the diet. Depending on the length of the carbon chain and the number, positions and isomeric structure of the double bonds they are differently metabolized. Available studies emphasize not only the importance of total fat intake, but also most importantly the fat quality for risk of disease. One of the most important health effects of dietary fatty acids is associated with atherosclerosis and its risk factors. Right choice regarding dietary carbohydrates should be made. Foods high in carbohydrates are also good sources of dietary fiber and many vitamins and minerals. Incidentally, little is known about the potential impact on risk factors for CHD of high-protein diets.

Results from the available studies are inconclusive considering the association between protein intake and risk of CHD. However, dietary protein from animal and from vegetable food sources appears to be differently associated with mortality from CHD when substituted for carbohydrates in the diet. High intake of protein from red meat and dairy products is, however, associated with an increased risk of CHD. Intervention studies indicate that higher protein diets increase short-term weight loss among obese and overweight subjects, but long-term data are so far scarce. The short-term effect has been attributed to the greater satiety and thermo genic effect of protein than of carbohydrates. More research is required to establish the effects of high-protein diets on renal function in the absence of albuminuria.

Good nutrition is the most important part for leading a healthy lifestyle. The link between good nutrition and healthy weight, reduced chronic disease risk, and overall health is too important to ignore. Novel approaches and renewed research efforts are needed to develop the appropriate foods to provide the best nourishment for healthy growth.