Have you ever worried that you’re going to turn into your parents? Well, if you’re not careful it’s going to happen sooner than you think—and in ways you might not have expected.

An April 2013 paper in the European Journal of Preventive Cardiology found that when it comes to metabolic health (basically, how well your body uses insulin to process the sugar in your blood), today’s 45 year olds are on par with 60 year olds of the generations before them. What does that mean for 20- and 30-somethings? Well, you do the math: Just add 15.

QUIZ: Find Out How Long Your Youthful Looks Will Last

The study measured various aspects of metabolic health, including the prevalence of being overweight or obese and body mass index (BMI). All three are notably higher in young people today than they had been in the past, with obesity among women in their 20s up twofold from a generation earlier. That means that a 20-something is two times more likely to be obese by her 30s than a woman 10 years older than she is. These scary generation shifts were seen nearly across the board for both men and women.

Poor metabolic health isn’t just about whether you can eat as much as your friend Sally without gaining weight. It’s the first step on the slippery slope to a heap of problems, from increased belly fat to obesity to type-2 diabetes, high blood pressure and high cholesterol. But fear not! You’re not destined to go down this road. Though there is a genetic component at play, you can control your metabolic health. Good lifestyle and eating habits will help you stay healthy and keep from aging ahead of your years.

Here’s what you need to do:

Get Moving

We’ve said it before and we’ll say it again: Regular physical activity—whether at the gym or by speed walking to work and actively tending your lawn—is a key to keeping your body humming along. Thirty minutes of aerobic exercise, five days a week helps you stay at a healthy weight, decreases damaging inflammation, helps regulate blood pressure and cholesterol and supports your system’s ability to use insulin efficiently. We’d really like you to take ten thousand steps every day. Start small and build (and by the way, a pedometer is much easier than counting).

MORE: The Exercise Cheat Sheet

Eat Smart

You know when you’re looking at a package of snack cakes that they’re not good for you. But do you really stop to think about what they’re doing? Routinely filling up on carbohydrates from white flour (cakes, white bread, rice) and tons of added sugar (why else would those treats taste so sweet?) forces your body to pump out more and more insulin to break down the torrent of sugar rushing through your bloodstream. Eventually, your body gets so used to those levels of insulin that the same amount doesn’t work anymore. That’s called insulin resistance, and it’s just a step away from type-2 diabetes. What’s more, packaged foods are full of trans fats, which contribute to high cholesterol. That snack doesn’t seem so so sweet after all, does it?

Skip the Soda

Did you think that just because diet soda was calorie-free that it was guilt-free, too? Sorry to break it to you, but even drinking diet sodas is associated with a higher risk of metabolic syndrome, a nasty combination of many of the risk factors of metabolic aging. The sugar and corn syrup in regular (sugared) soda is a major source of calories and a leading culprit in this country’s fight with obesity. Surprisingly, the no-calorie sweetener in diet drinks may be dangerous, too. One study showed that having more than one soft drink a week—whether regular or diet—was associated with a 44 percent increase in the risk of metabolic syndrome among 50 year olds. One theory is that the high sweetness of diet drinks causes people to crave sweet foods, eating more sugar in the end. Another thought is that some ingredients in artificial sweeteners might lead to insulin resistance or inflammation. Either way, steer clear and go for black coffee, natural teas, water or seltzer instead.

MORE: Good Carbs, Bad Carbs and Your Heart