06 Aug 2008

SA women's obesity burden

Diabetes, heart disease and stroke are but a few of the implications obesity holds for millions of women around the world. Today is International Day of Action for Women's Health and we are looking at the burden South African women carry due to this ever-increasing lifestyle-related condition.

More than 56 percent of South African women and 29 percent of South African men are classified as overweight or obese, according to a technical report released by the Medical Research Council (MRC) in 2006. This is higher than the figures reported in other African countries, particularly in women. Nearly 30 percent of South African women aged between 30 and 59 years are obese.

According to a study published in the South African Medical Journal by Joubert et al, a great percentage of incidents of life threatening disease in this country can be attributed to overweight and obesity. The statistics are as follows:

87 percent of type 2 diabetes (non-insulin-dependent diabetes)
68 percent of hypertension (high blood pressure)
61 percent of endometrial cancer (cancer of the lining of the uterus)
45 percent of ischaemic stroke
38 percent of ischaemic heart disease (heart attacks)
31 percent of kidney cancer
24 percent of osteoarthritis
17 percent of colon cancer
13 percent of post-menopausal breast cancer

Women and obesity
"It's a frightening prospect that the women of South Africa are caught in a spiral of ever-increasing weight, and are therefore more and more exposed to diseases such as diabetes, stroke and heart disease," South African dietician Dr Ingrid van Heerden wrote in a report.

She adds that studies have shown that South African women of all population groups are much more prone to being overweight and obese than their male counterparts, which places them at a higher risk of developing disease.

In a sample of 7 726 South African women aged 15 to 95 years old, black women had the highest prevalence of excess weight and obesity (58,5 percent), followed by women of mixed ancestry (52 percent), white women (49,2 percent) and then Indian women (48,9 percent).

Contributing factors
"Obesity is one of the modern world's biggest killers," said Professor Tessa van der Merwe of the International Society for the Study of Obesity, who also heads South Africa's first obesity clinic.

"We assume it is a US problem, but South Africans have been growing steadily larger over the last century. This is thanks to a confounding genetic predisposition towards energy conservation, lack of our ability to sense fullness, and a decrease in the amount of energy we use at the workplace."

Van Heerden adds that urbanisation in our country also contributes to obesity. "When previously rural people move to cities, they tend to become less active and eat highly processed, fatty foods that make them gain weight."

How BMI works
According to the World Health Organization (WHO), overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body mass index (BMI) is a simple index of weight-for-height that is commonly used in classifying overweight and obesity as it is the same for both sexes and for all ages of adults.

To work out your BMI you need to divide your weight in kg by your height in meters squared, for example if you are 1.65 m tall and weigh 85 kg, then you would use the following formula: weight / height squared = 85 / 1.65 x 1.65 = 85 / 2.72 = 31.25. So if you weigh 85 kg and are 1.65 m tall, your BMI is 31.25.

Alternatively use Health24's BMI Calculator.

If your BMI is between 18 and 25 then your weight is normal and you should try and maintain your weight at this level.

If your BMI is between 25 and 30 you are overweight and need to try and remedy the situation.

If your BMI is greater than 30 then you are medically obese and need to immediately do something to reduce your weight. It's worth bearing in mind that many people with a BMI of 30 or more don't necessarily look particularly fat: they may just look like large, or solid, people.

Interesting findings
The most common health consequences of overweight and obesity, according to WHO, are cardiovascular disease (mainly heart disease and stroke), diabetes, musculoskeletal disorders (especially osteoarthritis) and some cancers (endometrial, breast and colon).

However, new research has found some interesting links between overweight, obesity and other factors and conditions:

Infertility: Research from the Adelaide University in Australia shows that fat women have fatty eggs in their ovaries that are less likely to develop into healthy embryos.
Genes: Mutations in a gene governing the "fat hormone" leptin could explain some cases of childhood obesity, researchers report. Leptin is a hormone that helps regulate energy intake, and mutations in the leptin gene have been linked to early-onset obesity.
Baby bottles: Early exposure to chemicals used in the making of products such as baby bottles or plastic food wraps may lead to obesity, according to new research.
Cold: A common virus that causes colds can be a factor in obesity, according to a study offering further evidence that a weight problem may be contagious. The adenovirus-36 (Ad 36) has already been implicated as the cause of weight gain in animals, but with this study researchers showed for the first time that it can also cause humans to pile on the kilograms.
Psychological disorders: Heavy adults also have higher rates of psychiatric disorders, a study suggests. Using data from a national health survey of more than 40 000 Americans, researchers found that obese adults were up to twice as likely to suffer from depression, anxiety and other mental health conditions as normal-weight adults.
Antidepressants and aircon: The growing use of antidepressant medications and air conditioning may also be responsible for the increase in overweight and obesity, scientists say.
Baby fat: So-called "baby fat" in young children could be a predictor of weight problems much later on, researchers say. In fact, preschool-age children who are overweight before age 5 are five times more likely to be overweight at age 12 than those who were not overweight before age 5, a new study finds.

Source:
Strategies to combat obesity, Carine van Rooyen, Health24
Obesity: SA sitting on a time bomb, Dr I.V. van Heerden, Health24
Definition and causes of obesity, Dr I.V. van Heerden, Health24
Sapa
Reuters Health