The controversial theory is put forward by Eric Oliver, professor of political science at the University of Chicago in his new book 'Fat Politics; the Real Story behind America's Obesity Epidemic.'
Oliver claims that there is no scientific evidence to suggest that people who are currently classified as 'overweight' and even most Americans who qualify as 'obese' are under any direct threat from their body weight.
This comes into direct contrast with the plethora of information released by the government and by health bodies, which repeatedly links obesity with an increased risk of health conditions such as heart disease and diabetes.
And recently, a number of academic studies presented at the AACR International Conference on Frontiers in Cancer Prevention Research reveal growing evidence that overall cancer incidence and mortality resulting from overweight and obesity is also increasing, something which places more pressure on the food industry, and presents regulators with another headache.
But according to Oliver, none of this carries any weight.
In most cases, the relationship between fat and disease is simply an association, he claims. People who are overweight may also have heart disease, for instance, but there is no proof that being overweight causes the heart disease, he said.
"There are only a few medical conditions that have been shown convincingly to be caused by excess body fat, such as osteoarthritis of weight bearing joints and uterine cancer that comes from higher estrogen levels in heavier women, although this can be treated medically without weight loss," said Oliver.
"For most medical conditions, it is diet, exercise, and genetics that are the real causes. Weight is merely an associated symptom."
The 'obesity epidemic,' he argues, is simply a complicity between diet doctors, weight-loss companies and even the government to promote their own interests.
"Weight loss is a multi-billion dollar industry in America, and this industry is trying to put a health spin on what is a largely cosmetic product."
He goes on to accuse the US Centers for Disease Control and Prevention (CDC) of releasing faulty estimates about the amount of deaths attributable to obesity, and making false claims that obesity was soon to be America's number one cause of preventable death.
He also claims that the CDC has used maps that distort America's weight gain, making it seem like a spreading epidemic.
"We could end the obesity epidemic right now if we desired-all we would need to do is to redefine obesity according to the real criterion of a disease. If we simply classified obesity as a level where body fat is incontrovertibly pathological, only a fraction of Americans would qualify and this 'epidemic' would vanish," Oliver said.
If Oliver's claims were to hold true, they could relieve the food industry from mounting pressure to change ingredients, labeling and potion sizes in an effort to combat the epidemic, which is currently thought to affect more than 64 percent of the US's adult population and 16 percent of children.
However, over the past decade obesity has become so firmly established as an epidemic through health organizations, government bodies and the mass media, that one book is unlikely to let the food industry off the hook in the near future.