Fast food promotes childhood obesity

By Wasundara Rathnaweera

According to the Sri Lanka Demographic and Health Survey (SLDHS) 2006/07, obesity and over-weight prevalence among children under five years was 1.6 percent, with the highest prevalence in urban and estate sectors. Though recent data covering the whole country is not available since 2007, many studies support the fact that the incidence rate is increasing at an alarming rate.

World Health Organisation (WHO) has revealed the globally estimated number of overweight children under the age of five in 2010 is more than 42 million.

What is childhood obesity?

Truly, obesity is one kind of malnutrition. Malnutrition is simply the improper nutrition and refers to under and over nutrition. WHO defines overweight and obesity as "abnormal or excessive fat accumulation in the body that adds a health risk", which can merely be identified as over-nutrition. However, determination of child and adolescent obesity is not that simple as in adults due to number of physiological changes and continuous growth of their bodies. Biologically, a child is a human between the stages of birth and puberty. WHO Child Growth Standard Charts, CDC Growth Reference Charts are some widely used methods to assess their nutritional status.

They are either population based Z-score or percentile charts, which have been specifically developed with specific indicators in assessing nutritional status.

Weight-for-age, Height-for-age, Weight-for-height and BMI (Body Mass Index)-for-age are the basic indicators used in assessing child nutritional status. Cut-off value greater than +1SD (+1 Standard Deviation from the mean value of the population)of BMI-for-agein both sexes classifies as over-weight and cut-off value greater than +2SD of BMI-for-age classifies as obese in children.

"At least 2.6 million people across the world die each year, as a result of being overweight or obese". This statement stresses the danger of obesity. Therefore, the consequences of childhood obesity are not simple, as it is linked with a greater risk of early death and many serious disabilities or diseases in adulthood.

Overweight and obese children are more likely to step in to their adulthood as obese and there is a high possibility of developing some life threatening non communicable diseases (NCDs) such as diabetes and cardiovascular diseases at a younger age.

The age of onset and the duration of obesity are two major factors which determine the risk of NCDs. Therefore it is obvious that obese individuals who have continued their obesity from childhood are at a higher risk than those who develop obesity in late life.

WHO states that the most significant health related bad outcomes of childhood overweight and obesity are cardiovascular diseases (mainly heart disease and stroke), type 2 diabetes mellitus (T2DM), musculoskeletal disorders, especially osteoarthritis, and certain types of cancer (endometrial, breast and colon).

Due to obesity condition, body cells lose the sensitivity to insulin hormone, which is responsible for maintenance of blood glucose, hence develop insulin resistance. As a result of this, body cells fail to uptake glucose from blood stream leading to elevated blood glucose levels. This can ultimately lead to many serious NCDs such as type 2 diabetes, cardiovascular diseases and cancer.

What are the causes?

The prime cause of overweight and obesity is the positive energy balance,which occurs as a result of excessive calorie (energy) intake than calorie expenditure. Two major factors can be identified as reasons attributable to global increases in childhood overweight and obesity.

Unhealthy diets: Increased consumption of energy-dense foods which are high in fats and sugars but low in vital micro nutrients (vitamins and minerals). These foods are known as "Empty Calorie" foods.

Physical inactivity: Decreased physical activity levels due to busy lifestyles, sedentary nature of recreational activities, increasing facilities in transportation and urbanisation.

What is the role of "Fast Foods" in obesity?

"Fast food" is the term given to food that can be prepared and served quickly. Pizza, burgers, French fries and other short-eats like pastries, roles, and buns are some common examples for fast foods. These foods are also known as "Junk foods". Fast foods were first popularised in the 1950s in the United States and are now spread all over the world. They are popular among children due to many reasons. The notable reason for being popular among children is that the taste of these fast foods. Furthermore, they are instant and economical in most restaurants. When considering the nutritional content of these fast foods, they are reported to be energy dense up to 65% more than an average diet. Though these foods are high in calorie content, they are not rich sources of vital nutrients; specially in vitamins and minerals, and also poor sources of dietary fiber. High amounts of salt, sugar, and fat; particularly saturated fats in these food items are also being widely reported.

Unhealthy 'Industrially Produced Trans Fatty Acids' (IPTFAs) are found in many varieties of food from fast food outlets and takeaways; mostly occur as a result of the food frying in hydrogenated vegetable oils such as margarine.

The repeated reheating and cooling process of frying oils result in chemical changes within the oil increasing the levels of trans fats, and it is proven that some amount of fat can be converted into trans fatty acids through the deep frying process over longer periods with initially IPTFA-free vegetable oils.

These fast food products give less feeling of satiate due to low amounts of dietary fiber, inspiring the consumer to eat more(Dietary fiber adds bulk to the foods and gives the feeling of fullness or satiety very quickly. Therefore, fiber rich foods can limit the food intake, hence calorie intake). Furthermore, their high salt content makes children thirsty, resulting in consuming more sweetened soft drinks.

Due to the increased trend of consuming fast food items by children, numerous health impacts have been raised. High amounts of calories, fat and sugar in these food items are directly linked with obesity.

Obesity can be identified as the preliminary step of a series of dangerous health defects which are linked together. Owing to high amounts of fats and sugar, and low amounts of dietary fiber, these foods have become calorie dense foods.

Excessive intake of calories can be deposited in the body as fat, if they are not expended via physical activity. This scenario is known as the positive energy balance, which ultimately results obesity conditions. The danger is that children tend to eat more, due to their less satiety feeling and also the taste of these foods are preferred by children. On the other hand modern children spend a very sedentary life with no or less time spending for sports or any physical exercises. Due to high consumption of fast foods and less physical activity, they are unable to spend the ingested energy, thus it is more likely to accumulate energy in their bodies, resulting over-weight or obesity. Abnormal lipid profiles, high blood glucose levels and elevated blood pressure are obvious but unfavourable conditions in obesity.

Furthermore, fast foods are rich in saturated fats plus cholesterol, which are unhealthy in excessive amounts.

They tend to be deposited in blood vessels and obstruct the vessels, which ultimately results in cardiovascular diseases, leading to heart attacks or stroke. Trans fatty acids are extremely dangerous in elevated amounts as they can cause many types of cancers.

High content of sugar and insulin resistance of body cells due to obesity conditions may lead to type 2 diabetes mellitus in later life.

High salt content of these food items leads children to be hypertensive (High blood pressure). The most dangerous consequence is that these non-communicable diseases are long-lasting and life threatening.

What can be done to avoid obesity?

Since childhood obesity is becoming an epidemic, immediate action should be taken to defeat it. Parents are the key persons in the battle against child obesity. Really it is not a difficult task if you are willing to take the challenge.

Parents should promote healthy eating patterns within the family and encourage children to engage in regular, adequate physical activity. Children can be given home-made healthy and well-balanced meals which contain all the food groups adequately.

For instance, child's diet can include cereal or cereal based products (rice, bread, roti), vegetables, fruits, legumes (dhal, chick pea), source of protein like fish, meat or eggs (vegetarian children can be given legumes like soy, dhal as their protein source, but best is animal proteins), and dairy products like milk, yoghurt adequately, while they can be given sweets and fats sparingly.

It is not necessary to give these all food groups within one meal, but you should be able to balance all the food groups adequately in your child's meals within a day. You can easily go for home prepared healthy snacks like sandwich with omelet and vegetables or pancakes with fried vegetable mix which are prepared in an acceptable way by the child, instead of going for fast food snacks.

Consumption of fruits and vegetables can be promoted within your family and better to try various preparation methods to avoid rejection by the children.

Same time energy dense, high fat, salty and sugary food items (fast foods, sweetened beverages) can be restricted in your child's diet. Minimise saturated fats which are abundant mostly in animal meats. It is better to go for white colour meats like poultry (mostly chicken) after removing fat rich skin, instead of eating red colour meats like beef. You can reduce fat intake by removing skin of chicken. But in red meats, fat is not concentrated to skin or any specific organ which can be removed; consequently you will eat high amount of saturated fat with red meat. But fish would be a more healthy choice as a protein source, particularly fatty fish like salmon, tuna, trout and herrings as they are also rich sources of healthy fatty acids like omega 3fatty acids. Moreover it is important to emphasize drinking adequate amount of water to be healthy.

Apart from the dietary alterations, you can encourage your child to do physical activity; either they can engage in sports in their school or parents can give them opportunity to do safe cycling, walking or any other play events at their home.

It is important to reduce inactive time of the children, specially the time they spend in front of the television or computer.

More importantly, your child can be educated on importance of proper nutrition and selecting healthy food choices as they grow.

These are some easy tips to keep your child healthy. Though the fast foods have negative effects on your child's health, those can not be totally banned or avoided as sometimes these foods are really beneficial to busy lifestyles.

However, the Government can introduce some rules and regulations to make available healthy foods which are low in fat, salt and sugar, instead of currently available fast foods.

Still your child can enjoy these food items occasionally if your choice is wise and smart. It is all our responsibility to protect our children as they are the future of our country and its work force.

(The writer is a final year undergraduate at the Department of Applied Nutrition, Faculty of Livestock, Fisheries & Nutrition at the Wayamba University of Sri Lanka)