It’s hard to powerwalk 10 paces at this time of year without being exhorted to “get lean”, “drop two dress sizes” or “lose 30 kilos in 30 days”.
For people whose body mass index is above the “normal” range, losing weight is touted by mass media and health professionals alike as the cure for a range of health issues, from diabetes and heart disease to untimely death.
But some experts say focusing on weight loss as the ultimate goal gets it back-to-front, and that promoting a consistent set of healthy behaviours would see the whole population healthier in the long run.
An endocrinologist at the University of Adelaide, Professor Wittert leads a long-term research program into appetite, diet and other lifestyle factors in men.
“People should not focus on weight, people should focus on health. Then you don’t engage in these diets where you restrict your nutrients, and where people get depressed because they regain weight, which is almost an inevitability.”
If not weight loss, then what?
When people followed healthy habits for enjoyment and wellbeing rather than weight loss, they were more likely to stick to the lifestyle changes, staving off weight gain later, Professor Wittert said.
“If you switch the debate and say, ‘stay the same weight if necessary, but there are four or five things you can do to improve your health’ — then the pressure and distress is relieved.
“People do lose some weight but you also prevent further weight gain across the population.”
What are these four or five things? Well, a 2012 study found people who consistently had the following behaviours had a lower risk of mortality — that is dying over the course of the study:
- Regular exercise (more than 12 times a month)
- Diet rich in vegetables and fruit (at least five serves a day)
- Moderate alcohol intake
- Avoiding or quitting smoking
In this study, people who kept up with all four behaviours had similarly low risk of dying, regardless of whether they were classed as normal weight, overweight or obese.
To this list, Professor Wittert adds getting enough good-quality sleep, eating at regular times, restricting eating to daylight hours and reducing stress to optimise health.
Why losing weight gets so much credit
There’s not much evidence that people actually can safely lose weight and keep it off in the long run — that is, more than five years — according to Brisbane dietitian Fiona Willer, whose PhD research focuses on weight-neutral lifestyle interventions.
What’s more, she added, so few people achieve lasting weight loss that we can’t tell in a scientifically valid way whether it actually does lead to a longer lifespan than simply engaging in healthier behaviours.
Part of the reason we associate weight loss with better health is because restricting food brings short-term wins to measurable things like cholesterol and blood sugar, Ms Willer said.
Once you add that to the positive effects of boosting exercise and eating more wholegrains, fruits and vegetables, there’s a lot going on — but we tend to concentrate on the weight loss.
“When somebody goes on a diet you’ve got those elements all at play, but the weight loss gets the credit,” Ms Willer said.
People with a BMI in the normal range do have better health outcomes, she explained, but these people have usually lived their whole life in that range.
“It’s potentially that [history] that’s conferring a lower risk profile.”
While getting overweight and obese people to reduce their BMI to within the “normal” range is often prescribed as a pathway to better health, the evidence for this is inconclusive.
Most long-term studies find overweight and moderately obese people live just as long, if not longer than normal weight people, a phenomenon known as the Obesity Paradox.
This all points to thinking about health from a new perspective, Ms Willer said.
“We know we can’t get people to lose weight in a lasting way. But we know that getting them to move more is good,” she said.
“We know getting them to enjoy a variety of foods and connecting with the people around them is a universally good thing. We know that accessing medical care in a timely way that doesn’t stigmatise them is a good thing.
“It’s time to take a different approach.”
Weight stigma compounding health problems
Both experts said that weight stigma is a huge contributor to the health problems associated with obesity.
“Stigma so powerfully undermines everything. When people encounter stigma they’re no longer interested in making any effort,” Professor Wittert said.
Ms Willer said weight stigma was also artificially inflating the link between obesity and poor health outcomes.
“There’s this association between weight and chronic disease, that’s absolutely there,” Ms Willer said.
“But the devil is in the detail — and the detail is that people who move and eat well, and are in a higher socioeconomic level, and eat in a less disordered way, are less likely to have chronic disease.”
She said people from lower socioeconomic backgrounds became doubly stigmatised, firstly because of their income and secondly because of their size.
“They don’t want to present for screening because they don’t want to be in a situation where they’re stigmatised. The doctor dismisses symptoms they might not … if it was a person in a smaller body. Forty per cent of cancer patients in larger bodies are not dosed effectively for their chemotherapy.
“But when that person dies, their death is recorded against their BMI.
“There’s been so many gateways of discrimination that have unfairly inflated that figure [of deaths against higher BMI].”
That said, of course, there are situations where efforts to achieve significant weight loss are fully justified, Professor Wittert explained, for example when mobility is greatly limited because of weight.
Shifting towards health for every body
Focusing only on people in bigger bodies obscures the fact that most of us could do more to improve our health, Ms Willer said.
And it shouldn’t have to come down only to individual willpower — changes at the policy level could help us all to be healthier.
“How about everyone out there is supported to eat better? How about everyone moves more and our built environment supports that?” she said.
A recent study found that being obese but “metabolically healthy” (a measurement of things like blood pressure and blood sugar) was associated with an increased risk of heart disease, but being metabolically unhealthy within a normal weight range carried an even greater risk.
Professor Wittert said everyone should engage in healthy behaviours for the same reason they brush their teeth — because it’s good for you and prevents long-term disease — rather than trying to punish themselves into smaller bodies.
“Be healthy for healthiness’s sake, not for weight loss’s sake,” he said.
“That’s what’s going to make the most difference to the escalating cost of health care.”