There’s a meme aimed at Millennial catharsis called “Old Economy Steve.” It’s a series of pictures of a late-70s teenager, who presumably is now a middle-aged man, that mocks some of the messages Millennials say they hear from older generations—and shows why they’re deeply janky. Old Economy Steve graduates and gets a job right away. Old Economy Steve “worked his way through college” because tuition was $400. And so forth.

We can now add another one to that list: Old Economy Steve ate at McDonald’s almost every day, and he still somehow had a 32-inch waist.

A study published recently in the journal Obesity Research & Clinical Practice found that 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.

The authors examined the dietary data of 36,400 Americans between 1971 and 2008 and the physical activity data of 14,419 people between 1988 and 2006. They grouped the data sets together by the amount of food and activity, age, and BMI.

They found a very surprising correlation: A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. 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.