Updated 21 August 2013

Obesity: are our children doomed?

The growing obesity epidemic is putting our children at risk of adult lifestyle diseases such as heart disease, hypertension and type 2 diabetes, DietDoc warns.

The latest statistics on childhood diseases of lifestyle in the US are shocking. A Time article, "Sick before their time: more kids diagnosed with adult diseases" written by Alexandra Sifferlin, reports on the results of a large study conducted by Harvard Medical School. The investigators found that over a 13-year period there has been a 27% increase in the percentage of children between the ages of 8 to 17 years who have increased blood pressure. These children, therefore, may develop all the diseases of lifestyle that previously were only seen in middle-aged or elderly people.

Harvard study

In the Harvard study, the researchers compared 3 200 children, who had participated in the National Health and Nutrition Examination Survey (NHANES) III in the period 1988-1994, to more than 8 200 children who took part in NHANES in 1999-2008. The NHANES surveys are large, comprehensive studies which are carried out at regular intervals to collect data on the health, lifestyle behaviours and nutrient intake of Americans of all ages and ethnic groups. The purpose is to monitor the health and food intake of the nation and to decide on health and nutrition policies.

The fact that the investigators found that many more children were overweight with greatly increased waist measurements (an indicator of abdominal obesity), does not come as a surprise because the public have become used to the idea that populations in western countries like the US are getting heavier and fatter all the time.

But what most people did not envisage until now, is that these overweight and obese children are already showing the signs of the so-called "degenerative diseases of lifestyle" like hypertension, heart disease and type 2 diabetes before they reach their teens. In addition, medical experts point out that these children are having to receive treatment with drugs (antihypertensive and antidiabetic medications) at an age when they should be playing tag instead of having their blood pressure monitored and treated. A tragedy indeed.

Raised blood pressure

The children in the above mentioned study did not have full-blown hypertension (readings above 140-90 mm Hg), but their average blood pressure readings were above 120-80 mm Hg, which the American Heart Association (AHA) points out is a risk factor for stroke, heart disease and kidney failure (AHA, 2013). The AHA suggest that overweight with increased BMIs and waist measurements and an increased sodium (salt) intake may be responsible for the raised blood pressure results.

The Harvard Study found that girls tended to have larger waistlines and boys were more inclined to have raised blood pressure. For those children who weighed the most and were in the top 25% per age group, the chance that they would have increased blood pressure was increased two-fold when compared to the children in the lowest weight percentile (25%). African-American children were at even greater risk of having high blood pressure with an incidence of 28% compared to non-Hispanic white children. The children who ate the most salt, were 36% more likely to have higher blood pressure than the children who ate the least salt (AHA, 2013).
Youthful diabetes epidemic

Until recently, only a relatively small proportion of children had diabetes and practically all of these children suffered from type 1 diabetes. Consequently, paediatricians were trained to recognise and treat type 1 diabetes in their young patients. Now, however, paediatricians in the US and other countries with a western lifestyle, are being faced with an upsurge in the number of children presenting with type 2 or so-called adult-onset diabetes.

The suggested cause of this increase in type 2 diabetes in children is once again childhood obesity which is probably driving this epidemic. The American Academy of Pediatrics (AAP) has for the first time published "Guidelines to Manage Type 2 Diabetes in Children" in January of this year (AAP, 2013).

The Guidelines recommend starting treatment with insulin for all patients who suffer from ketosis or have ketoacidosis or have pronounced hyperglycaemia (raised blood sugar levels), while all other young patients in this category should be treated with metformin. Together with these medications, the guidelines recommend lifestyle changes such as dietary adjustment and an increase in physical activity.

The South African situation

So if these are the findings in a country like America, what does this mean for our youth in South Africa? Unfortunately we do not have vast population surveys which are performed at regular intervals to keep us up to date on the health and nutrition of our people.

What was identified in The National Food Consumption Survey (NFCS) 1999, conducted with 2 894 children aged 1-9 years, in South Africa which was published in 2000, was that 1 in 10 children was overweight (Labadarios et al, 2000).

In a follow-up survey known as the NFCS - Fortification Baseline 2005 (NFCS-FB-1), which was published in 2008, the researchers also found that 10% of children nationally were classified as overweight and 4% as obese (Labadarios et al, 2008).

The recommendations of the task team regarding overweight were as follows:
  • Breastfeeding should be promoted to help lower the incidence of overweight among older children (breastfed infants tend to be less prone to overweight and obesity in later life).
  • That obesity in children should be addressed in "the clinic, creche, school and home environment".
  • Physical Education should be reintroduced in schools in collaboration with the Department of Education.
  • School tuckshops should include "control of the sponsoring of school activities as well as a reduced intake of sweetened cold drinks and high-energy-nutrient-poor snacks".
  • Regular assessments of the health and nutrient intake of South African children should be undertaken in 3 to 5 year intervals. (Labadarios et al, 2008)

Not much evidence is at present available regarding the South African prevalence of diseases of lifestyle among our youth. When a special edition of the SA Medical Journal dedicated to the results of the South African Comparative Risk Assessment which had been carried out in the year 2000, was published seven years later, it contained 17 original articles which discuss Risk Factors threatening our nation’s health (Norman et al, 2007).

Most of these risk factors were assessed in adults aged 30 years and older. Some risk factors including vitamin A deficiency, iron deficiency anaemia, air pollution, and exposure to lead, studied children under the age of five years, while alcohol use, smoking and physical activity included individuals from the age of 15 years.

But as yet, no large, comprehensive study has been conducted since 2005 to try and determine if South African children are also at risk of being "sick before their time".

It is feasible that the South African situation is just as dire as the one in America and that we too should be concentrating on improving the diets and physical activity of our children from an early age.

In addition, it is vital that our researchers should be funded to continue studying the health and food intake of South African children to detect if there is an upsurge in diseases of lifestyle as early as possible to prevent our young people from being turned into premature middle-aged medicated patients.

Without proper detection, intervention and prevention, our children are doomed to also develop obesity, hypertension and type 2 diabetes.
(References: (AAP (2013). AAP publishes first guidelines to manage type 2 diabetes in children. American Academy of Pediatrics. Press Release January 28, 2013. AHA (2013). Elevated blood pressure increasing among children, adolescents. July 15, 2013. ; Labadarios D et al (2000). The National Food Consumption Survey (NFCS): children aged 1-9 years, South Africa, 1999, Pretoria: Dep of Health; Labadarios D et al (2008). Executive Summary of the National Food Consumption Survey Fortification Baseline (NFCS-FB-I) South Africa, 2005. S Afr J Clin Nutr, 21(3)(Suppl 2):245-300;  Norman R et al, (2007). A comparative risk assessment for South Africa in 2000. Towards promoting health and preventing disease. SA Med J, 97(8)(Part 2):637-641; Sifferlin A (2013). Sick before their time: More kids diagnosed with adult diseases. Time-com, 16 July, 2013.

- (Photo of overweight child from Shutterstock)

Dr Ingrid van Heerden is a registered dietician and holds a doctoral degree in Nutrition and Biochemistry. She believes that "we are what we eat" and offers free nutrition and weight loss advice via her DietDoc service on Read more of her articles.


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