Tackling the invisible obesity problem

Being slim does not necessarily mean being healthy, according to research from the Agency for Science, Technology and Research (A*STAR). Asian populations are more likely to store internal fat wrapped around their organs, while maintaining a slender outward appearance.

This genetic response makes it more difficult to recognise obesity in Asia as opposed to Western populations.

“The obesity you see in Asia is internal, it’s visceral. You may look skinny and have a pretty impressive BMI, but also suffer from an insidious metabolic condition,” said Christiani Jeyakumar Henry, director of Clinical Nutritional Sciences at A*STAR’s Singapore Institute of Clinical Sciences (SICS). “So you can’t use the normal BMI cut-off to articulate [an Asian person’s] risk of getting Type II diabetes.”

As a result, health-related issues stemming from obesity are also becoming more prominent in Asia, such as diabetes. In 2015, more than half of the 415 million people suffering from diabetes lived in Asia, according to data from the International Diabetes Federation.

“The diabetes rate in Asians is very high for example, even among those who have the same body weight as Caucasians,” said Shigeki Sugii, from A*STAR’s Singapore Bioimaging Consortium (SBIC).

Fats vs carbohydrates

Although some diets suggest eating less fat, this could cause more harm than good for Asian populations, who turn to carbohydrates instead. People of Asian descent have a higher blood sugar response to carbohydrates than Caucasians, which can increase fat accumulation from carbohydrates. This is problematic considering the Asian cuisine heavily features rice dishes. Therefore, the incentive to consume more carbohydrates such as rice rather than fats may be contributing to the rising obesity rates in Asia.

“In Asia people are eating up to 700 grams of cooked rice in a day, sometimes at breakfast, lunch and supper... We need to spend much more resources and money to look at food competence as we have done with pharma, because how on earth are we going to manage up to 50 million people who have Type II diabetes in China alone?” explained Henry.

Diabetes is a chronic disease that can dramatically increase the risk of cardiovascular problems, and nerve and kidney damage, which Henry highlights as being expensive burdens on healthcare systems.

Researchers are therefore looking for ways to reduce obesity levels and the health risks associated with obesity.

Eating behaviours

The principal investigator at the Clinical Nutrition Research Center (CNRC), Ciarán Forde, and his team examined the eating habits of Singaporean children, as well as their energy intake and body composition. Children who took larger bites of food and spent less time chewing consumed more energy within meals and had higher fat mass and body weight.

A team at the CNRC at A*STAR described an ‘obesogenic eating’ style as an opportunity to alter eating behaviours using a ‘food-based’ approach.

“The sensory properties of foods can stimulate food-related behaviours and directly influence energy intake over time,” said Forde.

Food texture directly impacts bite size and chew rate, therefore influencing the number of calories consumed during a meal, whereas odours can stimulate sensory-specific appetites.

Forde’s team used sensory experiences to influence calorie intake with techniques such as using harder, more textured foods in order to slow eating rates.

Body fat conversion

While white fat stores energy, brown fat is a rarer type of fat that is used for thermogenesis, a process in which the body burns energy for heat when a person is cold.

Research has found that when mitochondria increases in white fats, they can become similar to brown fats and have been labelled beige fats.

In 2009, brown fat was discovered in human adults as well as babies, which led to researchers trying to find ways to reduce white fats and increase the levels of brown fat in a person.

Feng Xu works for the A*STAR Institute of Molecular and Cell Biology (IMCB) focusing on brown and beige fat. Xu used epigenomic profiling and bioinformatic analysis to search for regulators that promote brown fat’s energy expenditure. He also discovered a micro-RNA known as miR-32 that enhances brown fat activity and can promote white fat burning.

He suggested that with further research, “there is a potential for miRNA-32 mimics to be explored for their function in promoting thermogenic activity in human brown fat to enhance the fat burning effect”.

Instead, Sugii, group leader of the Fat Metabolism and Stem Cell Group at SBIC, suggested improving visceral fat function by inserting brown/beige fats made from stem cells into it. This would make white fat more like the beige or brown fat just under the skin, meaning it could be burned more easily. According to Sugii, “It’s more effective and it can be more targeted.”

Henry suggests that Asia is a huge market and many companies are investing time and money in an attempt to address the rising obesity rate, ranging from changing food textures, encouraging fewer carbohydrates and finding methods to convert bad fat into good fat.