Obesity is one of the most pressing health concerns for both current and future generations. It is a major risk factor for cardiovascular disease, type 2 diabetes, some musculoskeletal conditions and some cancers. In addition, being overweight can hamper the ability to control or manage chronic conditions.
Governments and local communities around the world are trialling various programmes to tackle the epidemic. In the UK for example, the government is launching a pilot programme in January aimed at motivating people to lose weight by rewarding healthy living with clothes and food vouchers and discounted gym passes.
According to the Ministry of Health, New Zealand has the third-highest adult obesity rate in the OECD, and our rates continue to increase. One in three adult New Zealanders (over 15 years) is classified as obese, and one in 10 children.
While high-calorie diets and a sedentary lifestyle are linked to obesity, genes also play a role, regulating fat storage and affecting how well our bodies burn food as fuel. In the past, genomicists have identified hundreds of genes associated with obesity, however recent research from the University of Virginia has discovered 14 genes that actually cause obesity, and three genes that may prevent it.
The scientists hope to be able to use the research to develop anti-obesity gene therapies. Until then, obesity treatments focus on lifestyle changes, medication and surgeries, but with a new message.
The American Society for Nutrition says the public health message needs to move on from the ‘energy balance model’ – that is, weight gain occurs because individuals consume more energy than they expend – because the message has failed to stem rising rates of obesity. Instead, they say the focus needs to be on what we eat, as the current obesity epidemic is due, in part, to hormonal responses to changes in food quality.
The main culprits are high-glycaemic load foods and rapidly digestible processed carbohydrates that fundamentally change metabolism. When we eat highly processed carbohydrates, the body increases insulin secretion and suppresses glucagon secretion. This signals fat cells to store more calories, leaving fewer calories available to fuel muscles and other metabolically active tissues.
The brain perceives that the body isn’t getting enough energy, which leads to feelings of hunger. Metabolism may slow down in the body’s attempt to conserve fuel. Thus we tend to remain hungry, even as we gain excess fat.
The alternative to these kinds of foods are the less processed versions, so choosing whole grain bread over white bread, for example, and minimising foods with a high glycaemic load such as white rice, white bread, cakes, cookies and chips
