It's 3 p.m., and you're dying of hunger. Time for a little snack. You run down to the snack bar downstairs from your office and see a whole aisle of low-calorie snacks. Guilt-free satisfaction, right?

Oh, if only it were that simple. What's the food-to-air proportion in those bags? Are they more like balloons with a few rice chips thrown in? Will you have to do math to figure out how many calories you really are eating? And will they fill you up or just provide you with the sensation of eating something without actually making you feel satisfied? And what kind of funky chemicals will you have to swallow as the price you pay for cheap, low-calorie food?

I can't wait to peek inside a few of those bags. Let's open up some of those sad sacks.

I photographed the "official" serving of several packaged snacks. My hand is shown not because I've always wanted to be a hand model (although that is true), but to show scale.

Nabisco 100-Calorie Oreo Thin Crisps

Nabisco Oreo Thin Crisps

Serving Size: 1 package (23g)

Calories: 100

Total Fat: 2g

I think the idea is that these are Oreos, only with much thinner cookies and no filling at all. At least the ingredients list isn't horrifying -- just wheat flour, sugar, canola oil, cocoa, dextrose, cornstarch, leavening, color, salt, artificial vanilla flavor. But the taste? Cardboard. This is no way to "Diet like a Diva."

DR Delish Milk Chocolate DrizzlesDR Delish Milk Chocolate Drizzles

Serving Size: 28g, 1.3 servings per package

Calories: 120

Total Fat: 4.5g

First of all, for a snack with "120 Calories" printed on the package, there bloody well better be exactly one serving in there, right? But no. I have to get out my digital scale and separate out the 0.3 serving. Who does this? It makes such a negligible difference, why add that 0.3? Also, yuck!

DR Delish Sour Cream & Onion Spudzz

DR Delish Sour Cream & Onion Spudzz

Serving Size: 28g, 1.3 servings per package

Calories: 110

Total Fat: 2.5g

Again with the 1.3 servings! Whatever, it's more of that vaguely unsatisfying puffed food, though in this case you get a relatively large amount of it.

Riceworks Salsa Fresca Brown Rice Crisps

Riceworks Salsa Fresca Brown Rice Crisps

Serving Size: 28g, Servings per container -2

Calories: 140

Total Fat: 6g

That's no typo: the "-2" means there's just under two servings. At least it's a little easier to estimate half a bag. But do you ever buy a snack pack thinking "I'll just eat half now and the other half later"? I will say this, the chips do taste okay.

Barbara's Bakery Vanilla Snackimals

Barbara's Bakery Vanilla Snackimals

Serving Size: 30g, Servings per container about 2

Calories: 110

Total Fat: 4g

You buy kids' food, you get kid-sized servings. At least they taste better than those "giving up on life" adult snack cookies.

Kellogg's Strawberry Special K Bar

Kellogg's Strawberry Special K Bar

Serving Size: 1 bar

Calories: 90

Total Fat: 1.5g

Wow, look at that -- no serving-size trickery! Too bad the cereal bar tastes so unaccountably awful with its too-sweet, artificial strawberry flavor. And that's one scary ingredients list. Trust me, you don't want to know.

"Dirty" All Natural Potato Chips

Dirty All Natural Potato Chips

Serving Size: 1 bag

Calories: 300

Total Fat: 16g

Just for contrast I thought I'd show what some "real" unabashed junk food looks like. I love that these guys don't bother tricking you with the serving size. But really, the serving size is so generous I think I would share it with someone.

Doritos Cool Ranch ChipsDoritos Cool Ranch Chips

Serving Size: 28g, Servings per container about 2

Calories: 150

Total Fat: 8g

I ate a bag of these every day for lunch my junior year in high school. I don't know how I survived that year, either. But as you can see, these have the same calorie/fat content as the "Dirty" potato chips. Just, you know, they're doing that deceptive packaging trick. (Shaking my head.)

Duane Reade Spicy Cajun Trail MixDuane Reade Spicy Cajun Trail Mix

Serving Size: 30g, Servings per container about 2.5

Calories: 220

Total Fat: 15g

If the 100-ish-calorie packs leave you feeling a little empty, you could always take a 100-calorie leap and have nuts or trail mix.

Organic Valley String Cheese

Organic Valley String Cheese

Serving Size: 1 unit

Calories: 80

Total Fat: 6g

Yeah, cheese -- it's lower in fat and calories than the nuts, it's better for you, it tastes better, and it's REAL FOOD. This is such a no-brainer. Taking it apart slows you down and lets you enjoy your snacktime -- and you still feel filled.

Robicelli's cupcakes

I wrote about snacking on fruit last week, but I just want to mention again how well that works. Really, I promise. Do it for a week and see how you feel compared with how you usually feel when you eat these sad sacks. And then, on Friday, treat yourself to a truly decadent treat. I'll take a Robicelli's pumpkin caramel cupcake, thank you!

Do you snack on "Sad Sacks" or on real food?

Images via NabiscoWorld, Adriana Velez, Robicelli's Cupcakes