If your weekly routine consists of grinding out the 9 to 5 Monday through Friday, you are not alone. If you eat fast food for lunch on a regular basis, you are not alone either. Every day, millions of Americans take advantage of the quick, convenient and often tasty option for lunch. Quick, convenient and tasty, it sounds perfect doesn't it? It is actually a very consequential decision.

Although you are probably already aware a lunch time diet predominately involving fast food isn't exactly the healthiest option you can choose, you might be surprised just how severe the consequences actually can be. The average American needs 2,000 calories each day to maintain his or her weight. Of course, this number can vary greatly on an individual basis, but hypothetically, let's assume you need 2000 calories to maintain your current weight. It's important to remember, those 2,000 calories are for the entire day, not each meal. That's breakfast, lunch, dinner, snacks and beverages for a total of 2,000. Here is a simple breakdown of daily calorie consumption to meet this 2,000 calorie target.

A quick tip, many liquids have calories too! They count towards 2,000.

Breakfast- 300 Calories

Snack- 150 calories

Lunch- 500 calories

Snack- 150 calories

Dinner- 800 calories

Snack- 100 calories

So, by using the simple breakdown above, a person could consume a modest 500 calories at lunch and still maintain his or her weight. Does this usually happen, especially eating fast food? While it is possible to eat a fast food lunch less than 500 calories, it is not exactly typical. At a popular fast food restaurant the meal with the lowest caloric value had 940 calories. The meal with the highest caloric value had 1,380 calories. These meals consisted of a sandwich, medium fry and medium cola. This didn't include any of the highly advertised value add-ons which can add a significant amount of additional calories.

Even using the meal with the lowest caloric value of 940 calories, the lunch comes in 440 calories over the limit given using the model above. Hey, that doesn't seem too bad, 440 calories sounds like its nothing. At quick glance it might not seem that bad, but let's do a little math. You need two additional pieces of information, how many days you work in a year and how many calories are in a pound of fat. For this math problem, let's say you work 250 days in a year and, if you didn't know already, 3,500 calories equals one pound of fat.

440 calories X 250 days = 110,000 excess calories

110,000 excess calories /3,500 calories in 1lb of fat = 31.4 lbs of fat

You are seeing that right, if you eat fast food at lunch on a daily basis; you could be adding over 30lbs to your waist line every year. Just for fun, if you do the same math with the option with the highest caloric value, it comes out to over 60lbs in a year! The trouble doesn't stop at the waistline either; your wallet is under attack too.

Prices vary greatly by location, but let's assume you spend $3 per day if you pack your own lunch. Let's also expect you spend $6 per day if you eat fast food every day for lunch. That's a savings of $3 per day by choosing to pack instead of eat out. You might be thinking, 3 bucks, what can I buy with that? Well, let's do some more math.

3 dollars X 250 work days = 750 dollars

$750 invested yearly at a return of 5% for 18 consecutive years = $23,959.22

** This does not factor in inflation, so the actual number could actually be higher!

To put it into perspective, according to a 2011 report from the Institute for College Access & Success' Project on Student Debt, the average student owes $26,600 in student loans. Add in some birthday and graduation money and you could give your child a debt free college education by simply making better choices at lunch throughout his or her first 18 years of life.

The news is not all bad. If you are reading this article there is a good chance you are already demonstrating some poor eating behaviors at lunch time. By simply eliminating fast food from your diet at lunch time and limiting your caloric intake you can lose over 30lbs in one year. With weight loss, small changes make a big difference over time. Not to mention, you can save money for college or, at the very least, go on a pretty extravagant vacation with your savings.