No need to ditch your favorite movie-night snack when you're trying to lose weight. "Popcorn is a whole grain, meaning it contains fibre to help your digestive tract keep moving along smoothly," says Samantha Heller, an exercise physiologist and author of The Only Cleanse: A 14-Day Natural Detox Plan to Jump-Start a Lifetime of Health. "Since it's plant-based fibre, it also plays a role in improving gut bacteria, which recent research shows is key to preventing weight gain and promoting overall health." One last note from Heller: buy the bags of pre-popped kernels, since the microwavable kind can contain partially hydrogenated oil—a trans fat you want to avoid at all costs.
Yeah, yeah, yeah—we've all heard how sweet potatoes are a superfood. But did you know that the white spuds actually have a ton of health benefits, too? They're a good source of vitamin C and potassium, and one study showed that when people ate five to seven servings of potatoes a week, they still lost weight. (Granted, the subjects were on a reduced-calorie diet as well—but at least these findings show that potatoes don't hinder weight loss.) Again, portion control comes into play, says Heller. Don't go for the giant potatoes the size of a dinner plate, and skip spuds that come topped with bacon or cheese, mashed with cream and butter, or deep fried and dipped in ketchup. Instead, opt for one medium-sized potato topped with olive oil and salt.