Americans are getting some frustrating nutrition news right now: We’ve managed to cut calorie intake nationally over the last decade, but our obesity rates are going up—outpacing our overweight rates in general. The problem seems to be that everyone’s okay with consuming less, as long as they don’t have to do more.

Lazy, right?

So the good news is that overall calorie consumption is down. The average person is consuming less, and the category they’re consuming the least of is added sugars and sodas.

The bad news is that more Americans are now considered obese than overweight, which would seemingly indicate that the fattest among us have gotten fatter.

Those things might seem to contradict themselves, but if you look at the data, it’s showing a particular lifestyle is to blame for our hefty issues. Here’s the hard, blubbery fact: People are eating better, but they’re probably not taking care of themselves. “It is clear that the obesity rate in America has increased and continued to steadily increase,” says Yikyung Park, an associate professor at Washington University.

Park says that even if calorie intake has been dropping over the last decade, it’s only part of the problem. “To maintain a healthy weight, the energy eaten has to come out,” says Park.

And we’re not doing that as a society. Park says the data shows that “physical activity being done in America has gone down. People are not moving enough. And lifestyles are becoming sedentary.” Park points to screens as part of the problem, but also acknowledges transportation is a factor. “More people are spending time playing video games, [watching] TV, not walking, and car sales have gone up since the 1980s.”

Park hadn’t seen the calorie study, but confirmed that although some studies may now show that calorie count is going down, “even if we assume that calories are going down it doesn’t mean that people’s physical activity has gone up. If people are eating less but also they are not moving around,” she explains, “it means again that there is an energy imbalance. People are not moving enough to burn those extra calories, and will gain weight over time.”

Park also says that we’re compounding the problem when the extra calories come from nutritionless sources. “If the extra calories are coming from unhealthy food, it’s a problem for obesity and all other chronic conditions people are suffering from nowadays.”

So while the nutrition findings may mean a step in the right direction, people literally have to start taking extra steps.

“It’s not just a problem with one part. It’s all entangled. It’s really hard to tease out diet and activity from one person’s life,” says Park. “Generally people who tend to eat a healthy diet, those are the ones who probably move around a little more.”

That’s why people have to attack both parts of the problem, but there’s a big caveat here: Most physicians still recommend you start with one piece of the puzzle if you’re trying to make life changes. “You cannot make changes all at once,” Park says. “It has to be kind of step by step.”

Bottom line: Dropping soda or cutting calories to a healthy level is good. And it’s a good start, especially if they’re nutritionally void ones. “If people start cutting down those empty calories either from soda, or from alcohol intake, certainly in the long run you will see weight decrease,” Park says. “There are numerous studies showing all those added sugars in those beverages clearly show increased risk for diabetes and other diseases. It has consequences… so cutting back added sugar will be a good first step to lose weight or for healthy people to maintain weight.”

Now when we’re going to get our healthy lunches, we need to start taking the stairs, too.