10/05/2015 05:04 EDT | Updated 10/05/2015 05:59 EDT

It's Harder To Lose Weight Now Than It Was 40 Years Ago

The reasons why will surprise you.

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Side view of obese woman

If you aren't losing weight, you aren't alone. Researchers at York University say those trying to lose weight today face more obstacles than people 40 years ago.

“Our study results suggest that if you are 40 years old now, you’d have to eat even less and exercise more than if you were a 40 year old in 1971, to prevent gaining weight,” says Professor Jennifer Kuk of York University.

Researchers looked at the dietary data from 36,377 U.S. adults between 1971 and 2008, as well as the physical activity data of 14,419 adults between 1988 and 2006. After comparing the records, the research showed that based on their food intake, people in 2008 were 10 per cent heavier than those in 1971, International Business Times reports.

Kuk says the university's paper, which was posted in the journal Obesity Research Clinical Practice, shows that weight loss these days are affected by a lot more than calories in versus calories out.

In a press release for the university, Kuk says factors challenging weight loss include our environment, medications, pollution, genetics, stress and even nighttime light exposure.

But that doesn't mean you should give up hope. In addition to diet and exercise, getting a good night's sleep can also help you drop a few pounds.

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