This study relies on the NHANES data which is self-reported: Respondents have to recall what they ate. So an alternative and more likely explanation is that people are far better at deluding themselves than they used to be.
I would also assume that there's less structured eating schedules in homes now than there used to be, which would make it more difficult to catalog exactly what was ingested.
Even the methodology for acquisition of the self-reported data used in this study has changed over the years.
> In NHANES I (1971–1975) and NHANES II (1976–1980), in-person interviews were used to obtain self-reported dietary information via a 24-h dietary recall questionnaire that assessed food and beverage intake for weekdays only. In NHANES III (1988–1994), dietary information was obtained through a self-reported 24-h dietary recall using a computer-assisted, automated, interactive method for any day of the week. In NHANES 1999–2002, a multiple-pass computer-assisted dietary interview format was used to collect detailed self-reported information about all foods and beverages that were consumed the day prior to the in-person interview (weekday or weekend). In NHANES 2003–2008, 24-h self-reported dietary recalls were performed twice (3–10 days apart) using an automated multiple pass method.
I'm highly suspect of this one. This seems like an interesting avenue of exploration, but this data seems too weak to make broad claims from.
Yes and moreover we have statements such as " it’s harder for adults today to maintain the same weight as those 20 to 30 years ago did, even at the same levels of food intake and exercise." and "In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans."
These conclusions from a study with 36,000 people out of some 300 million Americans?
