It’s unfair but true: Even if young adults today ate the same diet as their parents did at the same age, they would still be heavier. According to a study published in Obesity Research & Clinical Practice, adults in the ’70s could eat more food and exercise less with significantly less chance of gaining weight.

The study observed the diets of 36,400 Americans between 1971 and 2008, as well as physical activity logs of 14,419 people between 1988 and 2006. Researchers found that people whose eating and exercise patterns were on par with people 20 or 30 years ago, still weighed about 10 percent more.

The study shows that weight management is much more complex than commonly thought.

“Our study results suggest that if you are 25, you’d have to eat even less and exercise more than those older, to prevent gaining weight,” Jennifer Kuk, a professor of kinesiology and health science at Toronto’s York University, said in a statement.

Kuk explained that some of the contributing factors include lifestyle, environment, use of medications, pollutants in nature, genetics, stress, timing of meals and even nighttime light exposure. Somehow in the last 40 years, American’s micro biomes have somehow changed, too. The Atlantic reports that Americans are eating more meat than than they were just a few decades ago, and much of this meat is treated with antibiotics or hormones to promote growth. These tactics might be gradually changing the bacteria in our gut. The proliferation of artificial sweeteners might also be playing a part.

“Ultimately, maintaining a healthy body weight is now more challenging than ever.”

So, if you can’t squeeze into your dad’s old military uniform or your grandma’s adorably retro coat, remind them how little they had to work out and tell them it’s not your fault.




Meghan is a full-time writer exploring the fun facts behind food. She lives a healthy lifestyle but lives for breakfast, dessert and anything with marinara. She’s thrown away just as many meals as she’s proud of.