"From government policy to media reports, fat is everywhere figured as a threat to individual, national, global health in physical, moral and economic terms.''
She said fatness had featured as a concern in medical discourse for centuries, but it was only quite recently that obesity had been defined as a disease in and of itself - a status she said was contested.
Ms Wykes argued that anti-obesity campaigns stemmed from neoliberal ideologies and targeted the most disadvantaged groups in society.
Part of her research looked at an Australian taskforce, and a subsequent public health campaign called Measure Up, that encouraged people to monitor their weight.
Such campaigns aimed to reform people's bodies to "save society from being literally crushed under all that fat'', she said.
Individuals who did not maintain their bodies at a particular size were cast as "bad citizens who threaten the economic prosperity of the nation''.
Ms Wykes said the emphasis on economic factors - the increased cost of healthcare and decreased productivity due to illness - created anxiety about sickness and disability, and devalued people who did not contribute to the economy.
Fat people were seen as non-compliant and out of control citizens who were enemies of the state, she said.
She noted the Australian taskforce found obesity was particularly prevalent among the poor.
"However, neither the report nor the campaign which followed it offered any way to challenge or change the structural barriers that it identifies.''
Ms Wykes said public health campaigns instead focused on altering the perceptions, beliefs and practices of at-risk populations.
"Anti-obesity interventions aim to reshape the consumption practices of the fat, the poor, the non-white, through the re-education of habits and reshaping of environments. This suggests that the war on obesity can in fact be understood as class war.''
Ms Wykes said it was a war against the most disenfranchised groups, both nationally and globally.
Victoria University historian Grace Millar told the conference the obesity epidemic was a historical event that stemmed from the neoliberal ideologies of the 1980s - but it was the most recent Labour government that introduced interventionist policies aimed at tackling it.
The government had wanted to correct health inequalities but was not prepared to change structural inequalities, she said.
"With the obesity epidemic, what they ended up doing was placing responsibility for health inequalities on poor people's bodies. So I think the obesity epidemic is fundamentally a discourse about class.''
Ms Millar said images shared on social media associated fatness with working class consumers.
Even poverty campaigners had bought into the idea that obesity stemmed from bad decisions made by poor people, she said.
The two-day Fat Studies conference will also tackle issues such as fat pride, children's lessons in fitness and fatness, weight anxiety and "unfixing'' body size and shape.
One of the conference organisers, Massey University human development lecturer Cat Pause, yesterday said stereotypes and stigma were placed on the fat body, but the relationship between weight and health was more complicated than people thought.
"As a fat activist and a fat scholar I want to change the national discourse on fatness and hopefully this conference will take another step in that direction.
"Fat people deserve the same rights and dignity as non-fat people, which we currently do not have.''
