Rapid changes in diets and lifestyles, occurring with industrialization, urbanization, economic development and the globalization of markets, have accelerated over the past decade. This has had a significant impact on the nutritional and health status of populations, particularly in developing and transition countries. While living standards have improved, food has become more available and diversified, and access to services has increased, significant negative consequences have emerged in terms of inappropriate dietary patterns, reduced physical activity and increased tobacco use, and a corresponding increase in diet-related chronic diseases, particularly among the poor.

Due to changes in diet and lifestyle, chronic non-communicable diseases including obesity, diabetes, cardiovascular disease, hypertension, stroke and some cancers are becoming increasingly significant causes of premature death and disability in developing and emerging countries. Major lifestyle factors that increase the risk of chronic non-communicable diseases include unhealthy diet and unsafe food, smoking, alcohol abuse, physical inactivity, etc.

Nutrition is emerging as a major modifiable determinant of chronic non-communicable diseases, with mounting scientific evidence supporting the view that dietary changes have powerful impacts, both positive and negative, on health throughout a person’s life. Most importantly, dietary changes can not only influence current health but can also determine whether a person will develop diseases such as cancer, cardiovascular disease and diabetes much later in life.

For chronic non-communicable diseases, the risk occurs at all ages; conversely, all ages are part of the continuum of opportunities to prevent and control these chronic diseases. Both undernutrition and overnutrition have negative effects on disease development, and the combination of both factors may be even worse. Therefore, ensuring a healthy, reasonable and safe diet throughout the life cycle, from preparation for pregnancy, through the stage of fetal development in the womb to the next stages of life, is important for the prevention of chronic non-communicable diseases.

Fetal development stages and maternal environment                        

There is evidence that intrauterine growth restriction is associated with an increased risk of coronary heart disease, stroke, diabetes, and hypertension. Fetal growth restriction may be followed by rapid compensatory growth after birth, which may be important in the underlying pathogenesis. Large birth size is also associated with an increased risk of diabetes and cardiovascular disease. High birth weight is also associated with an increased risk of breast and other cancers.

Infancy stage under 1 year old

Growth failure in infancy may be reflected in failure to gain weight and increase in height. Both growth failure and increased height or excessive weight gain may be risk factors for later chronic disease, regardless of birth size. Blood pressure has been found to be highest in those with fetal growth restriction and higher weight gain in infancy. Short stature is also associated with increased risk of coronary heart disease and stroke, and to some extent with diabetes. The risk of stroke and possibly death from cancer at several sites, including breast, uterine, and colon, is increased if shorter children exhibit faster growth in height.

Breastfeeding: There is increasing evidence that among term and preterm infants, breastfeeding is significantly associated with lower blood pressure in infancy. Feeding formula instead of breast milk in the first year of life has also been shown to increase diastolic blood pressure and mean arterial pressure in later life and to increase mortality in adulthood. Risks for several chronic diseases of childhood and adulthood, including type 1 diabetes, endocrine disorders, some childhood cancers, inflammatory bowel disease, and others, have also been associated with infant feeding of breast milk substitutes and short-term breastfeeding.

Childhood and adolescence

Childhood growth restriction has been observed to be associated with increased risk of coronary heart disease, regardless of birth size. A study of 11- to 12-year-old children in Jamaica found that blood pressure was highest in children with fetal growth restriction and greater weight gain between 7 and 11 years of age. A study of low birth weight Indian children was found to be characterized by low muscle mass but high fat stores that persisted throughout the postnatal period and were associated with increased central adipose tissue and thus increased risk of hypertension and disease. Higher blood pressure in childhood (along with other risk factors) induces anatomical and target organ changes in the body that are associated with cardiovascular disease risk, including decreased arterial wall elasticity, increased ventricular size and mass, increased systolic vascular dynamics, and increased peripheral resistance.

Short stature (including childhood height) is associated with increased risk of coronary heart disease and stroke, and to some extent with diabetes.

Relative weight in adulthood and weight gain have been found to be associated with increased risks of cancers of the breast, colon, rectum, prostate, and other sites. The International Agency for Research on Cancer has stated that there is clear evidence of a link between the onset of obesity (both early and late) and cancer risk.

Hypertension, impaired glucose tolerance, and dyslipidemia are associated with unhealthy lifestyles in children and adolescents, such as diets high in fat (especially saturated fat), cholesterol, and salt, inadequate dietary fiber and potassium, lack of exercise, and increased television viewing. Physical inactivity. 

Childhood energy intake is also positively associated with mortality from cancer, coronary heart disease, stroke, and respiratory disease in adulthood.

Adult stage

This is the stage when most chronic diseases manifest, as well as the decisive time for reducing preventable risk factors and for increasing treatment effectiveness.

Major risk factors during this stage are tobacco use, obesity, physical inactivity, cholesterol, high blood pressure, and alcohol consumption which increase the risk of coronary heart disease and stroke, diabetes, and cancer.

Aging and the elderly

Older adults are people aged 60 years and over. Most chronic diseases occur in this stage of life – the result of interactions between multiple disease processes and general physiological decline. Chronic diseases such as type 2 diabetes and some cancers reach their peak in this stage. The major burden of non-communicable chronic diseases is seen in this stage and therefore needs to be addressed.

It was previously thought that risk factors did not increase significantly after a certain age and that there was no benefit in changing habits, such as eating habits, after age 80. There was a time when older people were encouraged to change their diets, even if it was too drastic to get the desired benefit. More recently, older people have been encouraged to eat a healthy diet – as much and as varied as possible while maintaining their weight – and especially to exercise. Research has shown that older women who eat 5-10 servings of fruit and vegetables a day have about a 30% lower risk of atherosclerosis than women who eat only 2-5 servings a day. Older patients are at higher risk of cardiovascular disease, and they may have more to gain from modifying their risk factors.

Interaction between early and later risk factors across the life course

Low birth weight followed by obesity in adulthood is associated with a particularly high risk of coronary heart disease, impaired glucose tolerance, and diabetes.

Intrauterine growth retardation followed by rapid compensatory growth in weight and height increases the risk of chronic non-communicable diseases in adults.

There is also mounting evidence that an increased risk of coronary heart disease, stroke, and possibly diabetes occurs in adults with short stature.

Intergenerational impacts

Poorly growing girls often become stunted women and are more likely to give birth to low birth weight babies, who in turn may continue the cycle by becoming stunted adults, and so on.

Maternal birth size is a significant predictor of child size. There is clear evidence of intergenerational factors in obesity, such as parental obesity, maternal gestational diabetes, and maternal birth weight. Low maternal birth weight is associated with higher blood pressure in offspring.

Gene-nutrient interactions and genetic susceptibility

There is evidence that nutrients and physical activity influence gene expression and genome shape. Genes determine opportunities for health and susceptibility to disease, while environmental factors determine which susceptible individuals will develop disease. Gene-nutrient interactions also involve the environment.

In summary, there is a large body of scientific evidence that highlights the importance of adopting a life-cycle approach to the prevention and control of chronic non-communicable diseases. Key issues:

1. Unhealthy diets, physical inactivity and smoking have been identified as risk behaviours for non-communicable chronic diseases.

2. Biological risk factors such as hypertension, obesity, and hyperlipidemia have been established as risk factors for coronary heart disease, stroke, and diabetes.

3. Nutrients and physical activity influence gene expression and may determine susceptibility to disease.

4. Behavioral and biological risk factors emerge and exert their effects early in life, and continue to exert their negative effects throughout the life course.

5. Key biological factors may continue to influence the health of future generations.

6. Adequate and appropriate nutritional environment in the postpartum period is important.

7. Globally, trends in the prevalence of many risk factors are increasing, particularly for obesity, physical inactivity and, in the developing world especially, tobacco smoking.

8. Interventions that are selected as effective must extend beyond individual risk factors and continue throughout the lifespan.

9. Improving diet and increasing physical activity levels in adults and older people will reduce the risk of death and disability from chronic diseases.

10. Secondary prevention through diet and physical activity is an additional strategy to slow the progression of existing chronic diseases and reduce the mortality and disease burden caused by these diseases.

It is clear that risk factors must be addressed throughout the life course. Primary prevention interventions aim to move entire populations towards a healthier lifestyle. Small changes in risk factors in large populations can have a large impact on population risk of death and disability. By preventing disease in large populations, small reductions in blood pressure, cholesterol, etc. can lead to significant reductions in health care costs. For example, improving lifestyle can reduce the risk of developing diabetes by up to 58% over 4 years. Other population studies have shown that up to 80% of coronary heart disease cases, and up to 90% of type 2 diabetes cases can be avoided through lifestyle changes, and about a third of cancers can be avoided by eating healthily, maintaining a normal weight, and exercising throughout life.