I found the first two articles were interesting despite obvious flaws in the presented evidence. After reading the third one, it just looks like logical fallacy to me.

For example, taken from the first article:

> In the past, most people got slightly leaner as they got older.

How can you claim that with so few data. From the same data I would conclude that obese people die at young age...

I don't think we should exclude any possible cause but a global contaminant which is the only cause of obesity seems far fetched.

Simple logic would suggest that our food is the main culprit.

Personaly I would bet obesity is due to weakened gut microbiome (due to consumption of process foods), transmitted from mothers to their children. In other words, each generation consuming processed food gives birth to children more susceptible to obesity. It has actually been modeled with rats (cannot find the published link though).