Are protein bars really just candy bars in disguise?

I was traveling by air recently and eating my usual "lunch on the go"—a protein bar and an apple. Across the aisle, I noticed another passenger eating a candy bar. It made me think about recent studies documenting the deplorable state of the average American diet, and the rising rates of obesity.

Yet, at first glance, the snack he was enjoying and my quick lunch seemed similar. We were both eating a rectangular bar coated with chocolate icing. I wondered: is my protein bar really a healthier option or is it a lot more like a candy bar than I'd care to admit?

So, I carefully compared the nutritional contents of a Snickers Bar, a Luna Bar (Nutz Over Chocolate, my personal favorite) and, for good measure, a Nature Valley Oats 'n Honey granola bar. Here's what I found.

• Calories. The Snickers bar had the most calories per serving (250). But the serving size of a Snickers bar was larger: 52.7 grams, versus 48 grams for the Luna Bar and 42 grams for the granola bar (both of which were 190 calories per serving). This means that, gram for gram, the calorie counts were similar.
• Fat. The Snickers bar had 12 grams of fat. That's roughly twice as much fat as the other two bars, and more than a third of it was unhealthy saturated fat.
• Sugar and salt. Again, the Snickers bar was the loser, with its 27 grams of sugar being well above the 11 grams in the granola bar and 10 grams in the Luna Bar. However, the salt content was lowest in the Snickers bar.
• Protein. True to its billing as a high-protein food, one Luna Bar has 9 grams of protein — that's up to 20% of an entire day's requirement. The Snickers bar had 4 grams and the granola bar, 3 grams.
• Fiber. To be considered "high-fiber," a food should have 5 grams of fiber per serving. Only the Luna Bar came close to this, with 4 grams of fiber.
• Vitamins and minerals. The Luna Bar provides a decent dose of calcium (35% of your daily needs), iron (30%), folic acid (100%), and vitamin D (15%). Not bad! The other bars contained no significant amounts of these nutrients.

And one more thing…

Luna Bars are marketed as "The Whole Nutrition Bar for Women" because of the calcium, vitamin D, iron, and folic acid in each bar. So, if you're a woman, will these bars make you healthier? And what if a man (like me) eats these bars regularly?

It's true that women are more likely to develop osteoporosis than men, so it's important for women to get enough calcium and vitamin D. Women are more likely to become deficient in iron thanks to menstrual bleeding. And women of childbearing age should get enough folic acid to help prevent certain birth defects in their children. Even so, the amounts of the nutrients in a Luna Bar are unlikely to have much impact on the health of the average female (or male) fan.

So which snack will you choose?

When you get right down to it, a Snickers bar isn't all that much worse than many nutrition bars. For example, the difference in calories shrinks when the portion sizes are equalized. And the protein content of these bars won't make much difference for the person who already eats a well-balanced diet with other good sources of dietary protein. Nevertheless, I can't recommend a daily candy bar, although the occasional splurge probably won't harm you.

Remember, the "value" of any food has to be considered in the context of a person's overall diet, including the total balance of calories, protein, fat, and sugar consumed throughout the day. And let's not forget that the calories you burn through physical activity also matter a lot. I planned to work out as soon as I got home from my trip. I hope my fellow passenger was planning to do the same.