Portion size, why it is that a super-sized portion means a super-sized you.

Everyone has heard about the movie "Super Size Me" by now and has seen how a sustained period of terrible eating can do terrible things to your body. The protagonist in the documentary was up against a lot more than just lots of calories, but that was the primary contributor to his 24.5 lb weight gain over the 30 days of his experiment. He was a 6'2" guy who weighed 185 lbs to start. During the 30 days of his experiement he ate around 5000 calories a day. His BMR based on those figures is right around 2000 calories/day, which means that he was eating in excess of 2500+ calories/day assuming that he was minimally active (which was another constraint of his experiment).

So what?

Before we answer the "so what?" let's start by laying some baseline information. Calories are a measurement of energy. Calorie with a capital "C" is actually a kilocalorie, but we use Calories to talk about food because measuring in calories like physicists would give us giganticer numbers than we want to deal with. Your body needs a certain number of calories per day which it gets from food. Food is your fuel. There are three main pathways that those fuels take when you eat them. They get used for 1)energy now, 2)they get stored as energy specifically for muscle in glycogen or 3) they get stored away as fat.

Now let's answer the "so what?" question.

If I only need around 2000 calories per day to do everything that my body needs to do what does it do with the extra? It stores it! Let me introduce you to your friend, the liver. The liver organizes most all of this fuel. It's first job is to maintain your blood sugar. If you don't have enough glucose in your blood the liver will move glucose into your blood. If you have too much glucose in your blood, the liver will take it out and send it where it can be stored. Pretty handy organ to have, eh? The liver also does a lot to direct the storage of extra fuel as both glycogen and fat. But here's the deal, you're body can only store so much glycogen before it's full. Fat cells on the other hand just keep getting bigger and bigger the more you stuff in them. It's not such a bad system when you don't know when your next meal will be, but living a developed nation we can usually count on eating every day. Which means that if you don't want to store food as fat you need to control your caloric intake.

There are two really important ways to do this. First, keeping an eye on your daily caloric intake vs. output. If you are using 2600 calories a day and eating 3000 you are going to have 400 extra calories a day that the body wants to hang on to, which means more fat. This explains the well known idea that if calories in > calories out you will gain weight.

Let's get more specific though and talk about how much you eat at one time. Would you believe me if I told you that eating 5 times a day is better for your body composition than eating 3 times a day? What if I explained that you would be eating the same number of calories, but in smaller portions spread throughout the day? Think about the liver's priorities..1)blood sugar, 2) glycogen, 3) fat. All right, so now imagine you ate 2500 calories in 5 portions. That means that you would eat around 500 calories each time you ate. Not too bad. That's a big PB&J sandwich. But it also means that your portions are small enough that you are primarily addressing liver priorities #1 and #2. Once the food is used to balance your blood sugar and fill up your glycogen tank there may not be any left for your fat stores. Now that's pretty cool!

Try it and see how it works for you. The worst part is the inconvenience of eating outside of the normal Breakfast-Lunch-Dinner window. However, eating small portions several times a day, will help your body to store less fat and use more of the energy it is consuming when it enters the body.