DIET DEBATE

KAREN KISSANE

As we get fatter, the push is on to define obesity as a disease rather than a lifestyle choice.
THE patient was very fat, of the kind that doctors call “morbidly obese”; so heavy that her weight was likely to shorten her life. When she came to Dr George Blair-West for treatment, he did not weigh her or put her on a diet. He talked to her about her feelings.
He discovered that her mother had died when she was five, and her father had been a distant man. She felt food gave her the comfort and nurturing she did not have as a child: “Food came to have a very special meaning in her young life.”
Buried even deeper in her mind was another fantasy: that the sooner she died, the sooner she would see her mother again. For this woman, merely being told that obesity was damaging her health had no effect, because part of her did not want to live.
Blair-West, a psychiatrist and author of the book Weight Loss for Food Lovers: Understanding the Psychology and Sabotage of Weight Loss, says: “People have to stop thinking of obesity as a self-discipline problem. It’s a complex psycho-physiological problem more akin to an addiction.”
For Dr Joe Proietto, an endocrinologist and professor of medicine at Melbourne University, it is biology that has determined the fat person’s destiny. Psychological problems are a result of his or her obesity, not the cause of it.
“Severe obesity always has a physical cause,” he says firmly. “Moderate obesity is likely to be epigenetic (involving a change in which certain genes are switched on or off). And being mildly overweight is purely environmental.”
It’s a debate that has big implications for the mind, the body and the national health budget. Should obesity be regarded not just as a product of poor lifestyle, but as a disease in its own right?
This week the Federal Government announced a $3 million national nutrition survey in which thousands of Australian schoolchildren will be weighed and measured. Tasmanian Liberal Senator Terry Barnett has also suggested extending Medicare rebates to cover treatment of obesity as a chronic disease.
Traditionally, obesity has been regarded as an unhealthy condition and as a risk factor for other illnesses, but has not been seen as a disease in itself. The push to relabel it has gained great momentum in the world’s fattest country, America, where 65 per cent of adults are now overweight or obese.
In 2002, the US Internal Revenue Service ruled obesity a disease, allowing Americans for the first time to claim obesity-related health expenses such as surgery and weight-loss programs. In 2004, the US Medicare system also accepted that obesity is a disease.
In Australia, there is a push to follow suit. Here, adults got fat first (50-60 per cent are overweight or obese) but children are now following (25 per cent). In the last 10 years, the proportion of overweight children has doubled and the proportion of obese children (6 per cent) has tripled.
Most alarmingly, one in five preschool children – aged only three or four – is now overweight. Some experts have warned that the resulting diabetes, cancer and heart disease could bankrupt the health system.
Many people view an individual’s obesity as the result of a lack of willpower: too much time vegging out on the couch, and too many Bridget Jones moments with a box of Milk Tray.
Health Minister Tony Abbott has previously resisted calls for the Government to introduce bans on junk food advertising, arguing people are fat not because of advertising but because of poor diet and lack of exercise, and that the responsibility for children’s eating behaviour rests with parents.
But the more we find out about fat, the more simplistic that approach seems to be. Studies of identical twins suggest that up to 60 per cent of the predisposition towards obesity is inherited. Other studies have found that Darwin had it wrong; it does not take generations to produce genetic changes.
The way genes are “expressed” – rendered active or inactive – can be permanently affected by environmental factors within a single generation. This process is known as epigenetics. Proietto tells of a Dutch study which found that women starved in the first trimester of pregnancy (due to famine conditions during World War II) were more likely to produce children who would become obese. Another study found that women who ate too much during the first trimester also had fatter children; so did fathers who had started smoking in childhood.
Infection might even play a role: an experiment with chickens found that those infected with a common human virus, AD 36, became fatter even though they were fed exactly the same amount of grain as uninfected chickens who remained lean.
Children are more likely to be obese if they get less than six hours sleep a night, or if they were bottle-fed rather than breast-fed (one theory is that obesity among adults is partly due to the popularity of formula-feeding 50 years ago).
Proietto says rats that are starved in experiments and then given a normal diet become fat because their bodies’ long-term response to deprivation is to overeat.
“That diet early in life triggered something that not just made them obese at the time but then led their bodies to defend that obesity.” This would help explain why people who lose weight usually put it back on again.
It is now being speculated that genes affect not just metabolism but eating behaviour, such as cravings and sensations of fullness. Obese people have a resistance to the chemical leptin, Proietto says, which is created by fat cells, and sends signals to the brain about when to stop eating.
But the medicalisation of obesity has its opponents. Naomi Crafti, a lecturer in psychology at Swinburne University, says we are unnecessarily pathologising fatness.
“We are focusing on obesity rather than on health. Obesity is a risk factor for a number of illnesses, but it doesn’t mean that everyone who is obese will get those illnesses, and many people who are below the obesity level still do poorly because of poor diet with high sugar and fats. Obesity is just a descriptive term; it’s not an illness.”
Crafti says about 25 per cent of people with obesity do have a psychological problem known as binge-eating disorder, which is like bulimia without the purging. They gorge to cope with feelings such as sadness or anxiety. But many obese people have relatively normal diets and stay heavy because their metabolism has changed after years of fad dieting.
Dr Rick Kausman is the AMA’s spokesman on eating and runs the Weight Management and Eating Behaviour Clinic in Melbourne. He also condemns dieting. “I have spent 18 years listening to tens of thousands of people talk about their relationship with food,” he says.
” Almost every single person has said that 50 per cent, sometimes 80 per cent, of their eating is not related to hunger. They eat because they’re happy, sad, tired, bored, just in case they get hungry later, because their parents told them to finish their plate, because they are confusing hunger and thirst.”
Diets have told them to follow rules rather than attend to signals from their bodies, he says: “That paradigm doesn’t work and makes things worse.”
So, obesity is complex, it’s damaging and it causes great unhappiness. But does that make it a disease?
Dr Rob Moodie, the CEO of VicHealth, says: “If you rip apart the word – ‘dis-ease’ – then it probably is. Some do call it a disease. The World Health Organisation says obesity is a complex and incompletely understood condition.”
Obesity’s definitions are a bit shaky, he says: one researcher studied the All Blacks after rugby union’s World Cup and discovered that none of these powerfully built men had a body mass index in the normal range. There is also a question about whether obesity’s health problems are a result of weight or lack of exercise, fruit and vegetables.
There is no doubt that much obesity is lifestyle-related, the response of the human mind and body to what is, historically speaking, unaccustomed ease and plenty. This can be helped or hurt by the man-made environment. Urban design that makes it hard to walk, play or ride bicycles is known as “obesogenic”.
Blair-West points to one study of two towns in which differences in facilities and livability were associated with inhabitants of one place being an average of 30 per cent fatter than those of the other.
One Melbourne University study found that people living in disadvantaged areas weighed, on average, three kilos more than those in rich neighbourhoods. Even those with high incomes weighed more if they lived in disadvantaged areas, and the poor weighed less if they lived in affluent areas. Researchers said this pointed to the importance of neighbourhood characteristics, such as the number of parks and residents’ perceptions of safety.
While this suggests that public policy could help prevent obesity, it does not suggest it should be regarded as an illness. But proponents of the disease theory point to the way other lifestyle-related health problems, such as smoking and alcoholism, were much more effectively treated once approached as addictions rather than weak moral choices.
Boyd Swinburn, professor of population health and researcher into obesity prevention at Deakin University, says the major driver for relabelling obesity a disease is to make consultations claimable under insurance.
“In many ways, the ‘disease’ push is a political response. I think it’s a legitimate one if the end goal is to get improved care and management for people who have obesity.”
Melissa Wake, associate professor of pediatrics at the Royal Children’s Hospital and the Murdoch Children’s Research Institute, worked on the study that found that one in five preschoolers was overweight. She says the disease debate is not the central question.
“The distinction between disease and condition is an arbitrary one. It doesn’t get to the point, which is that we need to deal with this.”
LINKS
– www.vichealth.vic.gov.au
– www.weightlossforfoodlovers.com
BINGE-EATING DISORDER
About one-quarter of obese people have binge-eating disorder, which is characterised by:
· Recurrent episodes, at least two days a week, of eating significantly more than normal in a two-hour period
· Eating rapidly
· Eating when not hungry
· Eating alone because embarrassed at how much one eats
· Self-disgust, depression or guilt after eating
SOURCE: SWINBURNE UNIVERSITY OF TECHNOLOGYFirst published in The Age.