It's slightly more nuanced than "eat less and eat healthier," because the article is pointing the finger at some general abundance. If you like, look at this researcher's perspective directly. It's not why is this person obese but rather why is everyone getting obese? So he's not going to recommend that the problem is at an individual level, but at an institutional level.

If you wanted to translate this advice for institutions to an advice for individuals, I think it would instead be something like, "pay attention." The hardest costs to see are often the steady everyday costs -- that morning coffee, the groceries, subscriptions, and so forth. The conclusions that "abundance is the problem" and "we're throwing away too much food" seems to suggest that it has sneaked in during the moments when people aren't paying attention; people now don't pay attention to the quantity of food they buy, so more of it gets bought, more gets eaten, more gets thrown away. Look at the things that come automatic, be less worried about single failures and more worried about the general patterns.