From Farm to Fork - A letter from Dr G
Updated: Jul 17
The correct intake of macronutrients and micronutrients is essential to sustain the normal physiological activity in the human body. Yet the body’s requirements, in terms of calories intake, proteins, lipids, vitamins and minerals, varies at different stages of life. Failure to provide appropriate nourishment throughout the life course can result in malnutrition – undernutrition, where nutritional intake is insufficient; overnutrition when necessary thresholds are exceeded. Death, disability, stunted, mental and physical growth are a few of the consequences of malnutrition.
The global prevalence of undernourishment increased from an estimated 804 million to 821 million between 2016-2017. Malnutrition presents across the age and weight spectra, with 150.8 million children under 5 years recorded as stunted, 50.5 million as wasted children and 38.3 million as overweight in 2017. Worldwide, an estimated 1.9 billion adults are overweight, one in eight are obese and one in three women of reproductive age are affected by anaemia resulting in increased risk for both mother and child (1).
The “double burden of malnutrition” is defined as the coexistence of both undernutrition and overnourhished (overweight, obesity or with diet-related non-communicable diseases [NCDs]) individuals within the same community and across the lifecourse. Globally, almost one in three individuals suffers from at least one form of malnutrition and diet-related NCDs, contributing an estimated two-thirds of the 57 million global deaths annually.
Understanding the determinants of malnutrition is an important step towards addressing this serious global public health threat.
Behavioural factors, biological conditions, social, demographic and environmental aspects are considered to be major determinants of the double burden of malnutrition (2).
Evidence suggests that chronic disease risk factors manifest early in fetal life and persist throughout the lifecourse. Genetic inheritance, combined with epigenetics events that alter genes expression, have been shown to influence the risk of low birth weight, overweight, obesity and NCDs. In terms of negative determinants: maternal undernutrition may cause intrauterine growth restriction associated with an increased risk of hypertension, coronary heart disease, stroke and diabetes (3).
An increased risk of diabetes, cardiovascular disease and breast cancer has been positively associated with macrosomia (4). Irrespective of birth weight, retarded growth and excessive weight in early infancy may increase the incidence of chronic diseases later in life. “Catch-up growth” (in weight and height) may also have negative impacts on long-term health, supported by evidence to suggest a correlation with risk of stroke, diabetes and cancer mortality (5). In contrast, breastfeeding has been shown to confer protection and to lower blood pressure in childhood. Exclusive breastfeeding for a longer period of time may reduce the child’s risk of obesity in later, adult life. Conversely, feeding infants with formula milk may increase diastolic blood pressure and cardiovascular disease risk factors in later life.
Growth and development continue between infancy and adulthood with a maximum growth rate in early childhood. The increase in appetite for optimal growth may determine an excessive weight gain. Optimal energy and nutritional intake in the early, growth years are essential to appropriate weight gain and prevention of chronic diseases in later life. Unhealthy lifestyle choices that manifest in childhood and adolescence can persist throughout life, such as high intake of non-milk extrinsic sugars, saturated fatty acids, cholesterol, salt, accompanied by habitual alcohol and tobacco use and sedentary behaviour. Low intake of important vitamins and nutrients (e.g. vitamin A, iron, potassium, calcium, zinc and iodine) have been reported in teenagers, most probably due to a reduced consumption of fruit and vegetable. Peer and social media influences, familial socioeconomic status and lifestyle, sociocultural values can combine with personal food preferences, beliefs and emotions and result in suboptimal dietary habits. Substance abuse and psychological disorders may also influence eating behaviours. Lower socioeconomic status has a significant impact on food choices and is strongly associated with a lower intake of fruit and vegetables and more convenience foods, increasing risk of hypertension, central obesity, hyperlipidaemia and glucose intolerance, leading to a metabolic syndrome in later life. Evidence show that raised serum cholesterol level in adolescents is associated with an increased risk of cardiovascular disease mortality and morbidity (5).
Similar associations between unhealthy dietary and lifestyle choices and NCDs have been observed in adults. Indeed, robust and consistent positive associations have been established in adults between tobacco use, obesity, physical inactivity, cholesterol, high blood pressure, alcohol consumption and cardiovascular disease, stroke and diabetes (5).
Health is an ongoing journey that continues day after day with no interruption. It is affected by both beneficial and harmful exposures. Early interventions can target important developmental windows, but they must be maintained throughout the life course to achieve optimum physical, cognitive, social and emotional development and to minimise dietary-associated risk of chronic disease later in life. Sometimes cultural and religious practices such as fasting during the Ramadan may affect the nourishing of an individual. During periods of religious fasting, for example, glycogenolysis and lipolysis strive to maintain the blood-glucose level at or above 80 mg/dl, followed by a synthesis of ketone bodies in prolonged starvation. Mild dehydration, fatigue, headaches and impaired concentration are some of the symptoms associated with no water intake during fasting. Hypo and hyper-glycaemia, diabetic ketoacidosis, dehydration and thrombosis are the main concerns when people with diabetes participate in fasting. A small sample size study shows that maternal fasting during Ramadan affects placental weight and length of baby (6). Conversely, a systematic review and meta-analysis found no adversely affect on birth weight during fasting in Ramadan (7). Definitely further studies are needed to evaluate adverse maternal or neonatal outcome during fasting.
Ethical dietary choices such as veganism, which prohibits intake of all flesh foods, eggs and dairy products, also has important implications in terms of nutritional impact that must be addressed to avoid potential malnutrition. The critical nutrient, vitamin B12, for example, plays an essential role in pregnant vegan mothers. Vitamin B12 deficiency during pregnancy may cause hyperhomocysteinemia, preeclampsia, recurrent fetal losses, intrauterine growth retardation, preterm delivery, low birth weight and neural tube defects. Deficiency in vitamin B12 during pregnancy is also strongly associated with an increase risk of growth failure, anorexia, hyperpigmentation, abnormal EEG and delays in speech development of the infant (8).
From farm to fork, policy action is needed to eradicate hunger, resolve all forms of undernutrition, and tackle obesity. A mass media campaign targeted at consumer education, particularly among teenagers, is required. Policy interventions could target retailers and aim to limit the number of shops selling unhealthy food around schools and forcing shops outside schools not to offer cheap unhealthy choices could be a good starting point. Lower income families could receive benefits in the form of healthy food parcels rather than money and as rewards for undertaking regular physical activity. Imposing a fine in undertaking a physical activity to a person if found drunk. Selecting healthier choices when eating out can be achieved by updating restaurant menus with nutritional quality information.
Ultimately, healthy food must be physically, socially and economically accessible to everybody, with a particular attention to children under five, school-age children, adolescent girls and women. This will stop the transmission of malnutrition to future generations. Offering free fruits and vegetables and healthy eating courses in schools and community centres can be a way to tackle malnutrition. When healthy dietary options are not readily accessible the risks of low birthweight, stunting in children, overweight, obesity and NCDs in later life increase. At a global level, international governmental action is required to ensure food security and to fight against climate variability that could negatively affecting the availability, access, utilization and stability of current and future food supplies. Indeed, extreme heat, droughts, floods and storms pose significant climate-related threats to the future availability and cost of food. Provision of governmental aid to farmers affected by natural calamities may help to mitigate the resultant impact on cost of healthy foods for downstream consumers.
A low consumption of fruits and vegetables has been confirmed in many regions of the developing world, with a small minority of the population worldwide consuming the recommended average intake of fruits and vegetables (5). Distant are traditional ideals of children in the garden next to parents growing fresh, organic produce. Today, global urbanization distances agricultural and residential areas and reduces ready access to natural produce for urban dwellers while increasing the carbon footprint and cost of bringing produce to the table. So, let’s reduce the middlemen in the supply chain with government policies investing in periurban horticulture and enforcing rules in construction plans to leave green zones when building up new areas in cities. Consequently, less TV for our children and communal gardens for us where growing our own vegetables.
It is time to highlight nutrition on the international stage as a key global health priority and to work towards a common goal of good nutritional health for everybody, everywhere, at all times. Yet it is a challenging that requires engagement not only of governmental, policy and health stakeholders, but also of communities and their individuals at all stages of the lifecourse.
1. The State of Food Insecurity in the World 2018″. Food and Agricultural Organization of the United Nations. Retrieved Jan 11, 2019.
2. The double burden of malnutrition. Policy Brief WHO/NMH/NHD/17.3.
3. Programming of chronic disease by impaired fetal nutrition: evidence and implications for policy and intervention strategies. Geneva, World Health Organization, 2002 (documents WHO/NHD/02.3 and WHO/NPH/02.1).
4. Relation of size at birth to non-insulin dependent diabetes and insulin concentrations in men aged 50–60 years. Lithell HO et al. British Medical Journal, 1996,312:406–410.
5. Diet, nutrition and the prevention of chronic disease Report of a Joint WHO/FAO Expert Consultation
6. The Effect of Ramadan Fasting on Outcome of Pregnancy Vahid Z. et at. Iran J Pediatr. 2010 Jun; 20(2): 181–186.
7. The effect of Ramadan fasting during pregnancy on perinatal outcomes: a systematic review and meta-analysis. Jocelyn D. et al. BMC Pregnancy Childbirth. 2018; 18: 421.
8. To vegan or not to vegan when pregnant, lactating or feeding young children. Pawlak R. European Journal of Clinical Nutrition volume 71, pages 1259–1262 (2017)