4 Easy Diet Rules Carrie Underwood Swears By

Who doesn't love pasta, potatoes, and bread? Don't worry, Oprea isn't going to make you break up with them — you just can't eat them at night. Which makes sense, because eating healthy carbs like brown rice, oats, quinoa pasta, and whole grain bread earlier in the day will give you much-needed energy to get through the afternoon.

"The second you tell someone they can't have carbs, that's all they think about. It becomes an obsession. Or it works for a while, then they eat carbs again for the first, time and they can't stop and gain a lot of weight," Oprea says.

Because you're not burning as many calories at night as you are earlier in the day, those carbs are more likely to be stored as fat. Oprea recommends cutting off your carb intake at 3 or 4 p.m. And no, that doesn't mean you can gobble down as much as you want before then — you still have to make sure your choices are balanced.

Still crave pasta at night? Make simple swaps. (Like zoodles for spaghetti! Yum!)

We all know sugar isn't great for our bodies, which is exactly why our daily allotment is getting smaller and smaller.

Oprea recommends that you don't worry too much about how much natural sugar you're eating from fruit, but do focus on cutting back on added sugar instead. Look at nutrition labels carefully and don't pick up anything that has more than 5 grams per serving.

Also, be wary of baked goods, sauces, soda, and other foods that commonly have a whole lot of added sugar, sometimes sneakily disguised by these different names.

Don't worry, you don't have to completely swear off your wine nights. But Oprea does emphasize how many calories (and empty calories, at that) alcoholic beverages have. To beat the bulge, she says to stick to no more than two or three drinks per week. And if you still want to drink, try a healthier version or mocktail instead.