Obesity research

Obesity research

Fads Feed Flab

By Ufrieda Ho

It’s a riddle and a big problem: the science of human nutrition and diet hasn’t changed much, yet the obesity epidemic of modern humans is ballooning.

What has changed is the scale of modern food production, access to cheap fast foods, and corporatemarketing machinery that throws mere mortals’ willpower into the fire.

Obesity has hit a crisis point in South Africa: 26.8% of the population is classified as obese, according to the World Health Organisation (WHO). These bulging middles represent a health burden for the country as well as increased health risks and diminished quality of life for individuals.

And yet the research shows that eating a balanced diet to stay within a healthy weight range should be simple enough. Professor Shane Norris (BSc Hons 1997) says that from a population health point of view, the general rules are almost common sense: stick to all things in moderation; eat healthier whole foods; eat fewer processed, refined foods that are high in bad fats and sugars; exercise for at least 30 minutes daily; get enough quality sleep; break up long periods of sedentary behaviour; and keep stress at bay.

Norris, who is head of the African Centre for Obesity Prevention within the MRC/Wits Developmental Pathways for Health Research Unit, says that what keeps changing is the information about dieting. And this creates a lot of “white noise” around the science of nutrition. The distractions come in the form of fads: from the keto diet to the paleo diet, the Mediterranean diet to various forms of vegetarianism. It adds to the confusion and frustration for those desperate to fit into their clothes from three summers ago.

“Some numbers just don’t help – like counting calories or thinking about BMI (body mass index) only, or even trying to understand the information on a product label,” says Norris.

The number he is most interested in is 1000. This is the number of days from when a foetus is conceived to when a child turns two. Norris says the general health and the nurturing care of a woman at the time she falls pregnant and the care a child gets in its first two years of life are critical in determining lifelong health.

“The link is now well established between the health of the mother and the health of the infant in its first 1000 days determining the child’s risk of developing obesity, cardiovascular disease and diabetes,” says Norris.

Focusing on maternal health and those first 1000 days is likely to be an effective prevention strategy for combating obesity, he says.

Obesity afflicts just under 40% of women aged between 15 and 49 and about 8% of men in South Africa, according to the South African Demographic and Health Survey conducted by Statistics South Africa in 2016. That study also found that a further 30% of women are overweight.

“The aim is to avoid putting on excessive weight in the first place, especially around the waist area, because we know losing weight is difficult,” Norris says. Belly fat is the dangerous fat that covers the important organs, including the liver, pancreas and intestines.

Professor Karen Hofman (MBBCh 1978), head of the PRICELESS research unit in Wits’ School of Public Health, says it’s not just a case of encouraging people to change their lifestyle and behaviour based on scientific information. The real challenge, she says, is fighting the commercial interests of big corporates and the power of their marketing and advertising. Consumers are subjected constantly to misinformation and messaging that makes it difficult for them to make better choices. In particular, Hofman takes aim at the sugary drinks industry (which from April this year is subject to a special tax). She’s unequivocal about sugar as a massive contributor to the obesity epidemic.

“We simply don’t need sugar in our diets. You may want it, but you don’t need it,” says Hofman.

“The science about the danger of sugar in our diets has been known since the 1960s, but the power of industries that sell sugar has effectively shut out clear information for consumers. People are told they just need to burn off the calories they consume. But not all calories are the same. You’d have to do vigorous exercise for 30 minutes just to burn off one can of sugary cooldrink,” she says.

Hofman says sugars lurk in a wide range of foods and product information is hidden in small print and without enough helpful context about the health risks.

Sugar is in virtually every low-fat product. She talks about a “bliss point” – a salt/sugar/ fat ratio that food manufacturers rely on to satisfy palates. “When they remove one of the three they have to raise the quantity of one of the others to keep the consumer happy.”

The WHO predicts that non-communicable diseases will be the leading cause of death in Sub- Saharan Africa by 2039. Productivity loss related to ill health will cost South Africa 7% of GDP by 2030.

Hofman’s advice is to sort the science from the fads: choose a personal way of healthy eating that fits your lifestyle but is grounded in science.

“Eat a lot of vegetables; get the balance of protein and carbohydrates. If you’re going to indulge, keep it as a small, rare treat. And if it’s something that your great-grandmother would not have recognised as food, don’t eat it,” she says.

But just as gran might have been gobsmacked by the over-processed foods of 2018, she’d also be floored by the lives modern people lead, with our screen addiction, fast-food drive-throughs and supermarket till-points that can only be reached via a maze of food temptations.

It’s these changing socio-cultural environments and their impact on the upward obesity trends that interest Dr Nellie Myburgh. She has an academic background in agriculture, nutrition and anthropology and is a senior researcher at the Wits Health Consortium.

She argues for a broader view of what is contributing to the fact that around 600-million people worldwide are now considered obese or overweight. These are factors like genetics, lifestyle, sleep deprivation and psychological problems.

“Our bodies are perfect machines that know when we have had too much of something or when we don’t have enough of something else. But somehow we have lost this balance.

“Our modern lifestyles have changed faster than our evolutionary ability to adapt and it’s messed up our internal switch,” says Myburgh.

She also knows that the old wisdom of body, mind and spirit balance is not as easy to achieve as it sounds. Myburgh says: “We tell people to exercise by walking, but they may be too fearful to walk on the streets where they live because of high crime rates. We don’t consider happiness and a sense of wellbeing for people who may feel isolated or overburdened in their daily lives and then eat to fill a void. There are also people who can’t afford healthier foods,” she says.

Studies show that around 85% of modern people worldwide don’t get enough sleep. It can affect hormone regulation, which in turn affects things like healthy weight management, she says.

Even the changing ideas about ideal body image are confusing. Social media is filled with the extremes of “fat-shaming” on the one hand and “body positivity” on the other.

Myburgh points out that in some communities being slim is considered a sign of being HIV positive. As a result people may seek to pile on the kilos to

avoid being stigmatised. These mixed messages, she says, can compromise people’s health as they internalise the wrong messages about what is healthy.

It’s clear there’s no quick or easy way to defuse the public health time bomb of obesity. But it’s even more obvious that there’s no time to waste. It’s a fact: too much fat is not fabulous.