I'll hope it's legit, but considering they're going off food diaries when we know people underestimate their consumption and food purchases and production when we know that food waste is prevalent (meaning it's difficult to tell from just the provided information if more food is actually being consumed or if waste vs. consumption ratio just makes it appear so) makes me wonder if this is just wishful thinking. They say the shift in the stats happened around the time we became more aware of the impact of obesity, but that's jumping to conclusions. You could also conclude that people became aware of the negative impact of obesity and began to deny their issues with weight, knowingly or not, and underreported the issues further.

When doing diet recalls and food frequencies we're specifically instructed to not give any feedback on what they report because people want to make you happy, they want to sound like they're trying, they don't want you to know they ate that Snickers bar, etc. If people realize something is non-ideal and you allow them to self-report they're probably going to under-report the bad and over-report the good. That's just as viable of an explanation for why this education about obesity coincided with self-reported improvements in eating habits.

Regardign not much change in obesity trends, for years I was obese. If you'd polled me in 2005 I'd say I was obese. If you'd polled me in 2012 I was obese. No change? Hardly. My BMI had increased from, say, 36 to 44.3. In fact, the article discusses this:

Perhaps the biggest caveat to the trend is that it does not appear to extend to the very heaviest Americans. Among the most overweight people, weight and waist circumference have all continued rising in recent years.

I like the positive attitude the author of the article takes but they're inferring a lot that isn't explicit in the data.

(Slightly modified these comments which I made when this was posted earlier today but the OP had deleted the post for some reason.)