Obesity is associated with expanding economies because, well, there's more food and money. However, obesity isn't mentioned in the article, and is probably completely unrelated to this.
It is interesting however that GDP only increased in countries where food is eaten quickly, although a broader sample would be better. However, I don't eat fast for the reason of production, I don't even believe myself to eat fast. Perhaps it's related to the types of food people eat; the countries which have less emphasis upon their own cultural food appear on the left. I, being in Australia, don't feel I eat food quickly. However, I can't see why a person would be so slow as to eat it over more 100 minutes in a day.
In addition, these results seem almost tainted by anomalous results. Sweden, Australia and Norway were the only ones with actual growth in the last year. Funnily enough, everything else is almost perfectly consistent with the slow-eating countries. The medians are almost identical, and the means would probably be once you discounted the countries which recorded growth. Perhaps this is simply coincidental? I mean, Sweden is in the 90s -- the results would be completely different if they ate, on average, 10 minutes longer each day They're nowhere near as fast eaters as Mexico, for sure.
It's also questionable as to if Italy and France have higher qualities of life; it depends upon what you're looking for in life. Perhaps we should check the HDI for each country, at least? That'd provide a (very) crude measure, at least.
I think it's the other way around.
I think people eat faster as a result of being in a country with a faster GDP growth rate. They are more busy, working more hours, etc, resulting in less time to relax and enjoy their meals.
Hogwarts nailed it! The more money you have the more food you can have. In old times, kings were overweight and peasants were skinny.