It has become a cliché to discuss William Banting's Letter on Corpulence before talking about dietary carbohydrates and obesity. However, I think his letter gives more insight than simply the macronutrient composition of his diet.
In short, William Banting was a retired undertaker who had become obese by his 60's. Despite numerous efforts and treatments, he was unable to lose weight. Eventually, a physician prescribed a diet low in breads, sugar, and dairy, but high in meat and non-starchy vegetables and some fruit. Banting effortlessly lost approximately 50 pounds over the course of a year; all while consuming a surprisingly large amount of wine and liquor. The diet was such a panacea, that he was inspired to write a pamphlet in order to "confer a benefit on my fellow creatures."
It can be found here: http://www.archive.org/details/letteroncorpulen00bant
It's a quick read, and I think it provides a pertinent perspective on the history of diet and obesity. I took notice of three things:
1. Obesity wasn't exactly uncommon even in the 19th century (wide-spread obesity is unique to our generation), and it was also considered a seemingly necessary part of aging. This occurred despite the absence of fast food, television, and bright-colored-tempting candy bars at the check-out counter.
2. Little has changed: The obese were regarded as slothful and gluttonous, and they were quite aware of these perceptions and despised their condition. Eating less and exercising was prescribed and followed, but this only lead to hunger and subsequent failure. The obese have always tried.
3. He observed that certain foods are fattening and others are not. Avoiding the fattening foods allowed him to eat to satisfaction while losing weight and improving vitality and quality of life.
I'm especially impressed by how reasonable his attitude is towards his diet. Starches and sweets make some people fat, while meat and vegetables do not. Starches and sweets are difficult to give up, but it's more difficult to be obese. Simply reduce the starches and avoid the sweets.