When those afternoon hunger pains hit, are you the kind of person to calmly prepare yourself a nutritious plate of hummus and veggie sticks? Or the type to make a mad dash for the vending machine, blindly jabbing in numbers until a sugary/salty treat falls out?

Unfortunately, our four volunteers fit the latter description more often than not -- but fortunately, they were eager to change their unhealthy snacking ways. To help, we set them up with clinical nutritionist Stella Metsovas, BS, CCN. She looked over a typical day of snacking and suggested easy swaps that would keep them full, happy, and away from the leftover donuts in the break room. Could you use some snack help too? Then keep reading and see which of Metsovas' suggestions fit your diet and lifestyle as well.

For more snack ideas, check out these smoothie recipes.

Morning snack: banana, coffee, and half a granola bar

Afternoon snack: frozen yogurt (with plenty of toppings)

Late night snack: glass of wine and whatever her boyfriend made for dinner

Lisa's biggest issue is her work schedule. She spends three hours a day in her car commuting, which means little time to prepare healthy foods, and she eats very late dinners (bordering on midnight snacks) each night. "I would like snacks that provide more energy so I'm motivated to work out after work, since I sit at my desk and in the car all day."

"The No. 1 thing I noticed is she always consumes dinner late and then she says she gets really hungry mid-morning," Metsovas says. "She's eating the majority of her calories late at night and her body isn't digesting them." Metsovas explains what happens when you eat too much before bedtime: "You're missing quality sleep because your body is trying to digest this huge meal. So you wake up tired and that makes you extra hungry."

She also points out that Lisa's morning snack has a lot of carbs, which our bodies don't really need when we're just sitting at a desk, and her afternoon snack is loaded with sugar. "Some frozen yogurts can have 60 grams of sugar per serving!" she says. Here are her suggested snack swaps:

Morning snack: "You can have black coffee if you absolutely need it," Metsovas says. But she says instead of the banana and granola bar, try a hard boiled egg with some arugula and olive oil. "Try to have real food, almost a small meal, for a snack."

Afternoon snack: "Instead of frozen yogurt, try a Greek yogurt," she says. "It has a custard-like texture so it still almost feels like you're having something bad for you." (One to try: Dannon Light & Fit� Greek Yogurt, it has 80 calories, 0 percent fat, and twice the protein of regular lowfat yogurt.) "You can mix it with a little honey and frozen berries for a nice treat."

After a few days of her new snacking routine, Lisa realized it was actually easier than she thought to stay healthy. "I made a few hardboiled eggs the night before and in the morning it was an easy snack and the crunch of arugula was nice with the egg," Lisa says. "The Greek yogurt was easy as well, although I do tend to pile on the honey, it's still better than any toppings I would add at the frozen yogurt store."

Morning snack: roasted almonds and pop chips

Afternoon snack: hummus with pita chips

Evening snack: Ice cream, popsicles, cheez-its, "basically all those childhood favorites your mom wouldn't let you have"

Heather is on her feet all day for work, so she needs snacks that will give her plenty of energy and won't take too much time to eat. She's also underweight (in part because she doesn't always find enough time to eat during the day) and wants snack ideas that will help her with this as well. "I'd like to work out more and do strength training to build muscle, but I'm always so tired after work."

Metsovas agrees that Heather needs nutritious snacks that'll give her lots of energy to get through her busy day. Here are her suggestions:

Morning snack: "Make a power smoothie with whey protein, coconut milk, fiber, and berries," Metsovas says. She can also eat some raw, unsalted almonds for extra protein.

Afternoon snack: Metsovas says the hummus isn't a bad choice, but if she swapped the pita chips for veggie sticks she would up her phytonutrient intake.

Evening snack: "Replace your junk food snacks with other childhood favorites like celery and natural peanut butter," Metsovas says. "You'll have those same emotional benefits without the stuff that's bad for you."

Heather loves the smoothie idea. "They are so yummy!" she says. "I feel fuller longer and I have more energy." She also said she actually likes the raw, unsalted almonds better than her old roasted ones and the carrot sticks are still a nice snack with her hummus. "I'm working on giving up the ice cream though, it's hard!"