In February 2010, First Lady Michelle Obama launched 'Let's Move', the most high-profile anti-obesity initiative in the United States to date.

Allocating $US10 billion over 10 years, the 'Let's Move' initiative takes a four-pronged approach to ending childhood : encouraging physical activity, improving access to fresh fruits and vegetables in underserved areas, modifying school lunch menus to conform to stricter dietary guidelines, and providing nutrition information to parents.

These are all well-intentioned measures, but they fall far short of what it will take to significantly reduce childhood obesity.

In recent years, scores of researchers have demonstrated links between socioeconomic status and obesity, and suggested that obesity is in part a function of social inequalities. To significantly reduce rates of childhood obesity, it is therefore critical that we make political reforms to address poverty.

In 2010, the results of a US Department of Health and Human Services-sponsored survey of 46,707 children (aged 10 to 17) in 2003 and 44,101 children in 2007 showed that some of America's poorest states - Mississippi, Georgia, Kentucky, Louisiana, and Tennessee - also led the nation in rates of childhood obesity. Notably, the authors of the survey emphasised that "the adjusted odds of obesity or overweight increased significantly in relation to decreased levels of household income".

A 2005 study by Ohio State University economist Jay L Zagorsky calculated precise linkages between BMI and wealth. The study, which included 7,300 participants in a longitudinal survey, found that each additional unit increase of BMI correlated with an 8 per cent reduction (about $US1,300) in .

While the association between weight and income was negligible among African-American men, and relatively modest among white men, the study found a clear inverse relationship between BMI and wealth among women. Among African-American women, a one-unit BMI increase corresponded to a 7 per cent decline in net worth; for white women, the difference was 12 per cent.

Another survey conducted by University of Washington researchers in 2007 similarly found that obesity rates in King County, Washington, declined as neighbourhood property values rose. Neighbourhoods registered 2 per cent lower rates of obesity for every $US100,000 increase in median home value. This meant that in the most upscale King County zip codes, obesity rates were a mere 5 per cent, but they were as high as 30 per cent in the region's poorest communities.

The situation in Australia is similar, with our remote and regional communities facing comparable challenges. In far-west NSW, the of 37.2 per cent eclipses the highest rate in the US, 35.1 per cent in Mississippi and West Virginia. By contrast, the obesity rate in Northern Sydney is just 11.1 per cent.

There are manifold reasons why those living in both urban and rural poor communities are predisposed to obesity. The familiar explanations that undergird initiatives like 'Let's Move' consider that the poor face barriers to regular exercise and have few healthy, affordable grocery options. Frequently proposed antidotes to these constraints include building playgrounds and grocery stores in neighbourhoods lacking them.

But in addition to these proposals, a broader, more effective solution would be to help the poor achieve socioeconomic mobility. Once people obtain higher levels of education and income, they are in a better position to make healthier lifestyle choices for themselves and their children. This phenomenon can also have a ripple effect in which weight-loss among the upwardly mobile serves as a model in peer groups.

In his 1987 book, The Truly Disadvantaged: The Inner City, The Underclass and Public Policy, Harvard sociologist William Julius Wilson argued that social isolation and lack of visible models of success in poor, inner-city African-American neighbourhoods reinforced structural problems of poverty, crime, and unemployment. Almost 30 years later, Wilson's thesis could be applied to patterns of inter-generational obesity, as poor, obese parents are more susceptible to raising overweight children.

A 2007 study by researchers Nicholas Christakis and James Fowler also found that obesity was "contagious" among people within the same social networks. Perceptions of what constituted normal weight shifted according to friends' weight gains and losses, and having an obese close friend raised one's chances of becoming obese by 57 per cent. Poor people, then, are also vulnerable to obesity because the people by whom they are surrounded are more likely to be overweight.

If we are to tackle , it is imperative that we introduce macroeconomic reforms to alleviate poverty. Job training programs, improved public education in poor communities, moving low-income households to more advantaged neighbourhoods, and other measures to facilitate upward mobility are necessary to tackle the socioeconomic dimensions of the cycle of obesity. To be sure, fighting poverty is an extraordinary challenge. But the current obesity crisis among the western world's poor is one more reason to try.