Posted by: Joe English | June 19, 2008

Training: Food as fuel; your diet, weight loss and running (part I)

Coach Joe English

Coach Joe English

Part I: Food is fuel, start thinking about it that way

In an earlier article I discussed an observation: many of my runners clients who are trying to lose weight don’t always see the pounds come off as quickly as they would like. In fact, in client follow-up surveys I conducted over the past three years, most respondents told me that they didn’t lose weight initially when they started their running program. Some even gained weight.

My main point in that article was that diet is of enormous importance in weight loss for runners – as obvious as that may sound – and that while exercise burns calories, if the person continues to eat too many calories they may still not lose weight.

After making these somewhat maddening observations, runners have asked me on several occasions the simple question then of how – pray tell – does one go about constructing a diet to lose weight for a runner?

The basics of nutrition
First, let’s start with the basics. Food taken into the body should be thought of as fuel. Just like you would put gas in your car to run the engine, you put food in your body to make your body go. The difference, however, between you and your car is that there are several different kinds of fuels that you can put in your body and the body does different things with each of them.

Since most cars run on “fossil fuels” then let’s just say that humans run on “food fuels.”

These food fuels can be broken down into thee main groups: proteins, fats, and carbohydrates. Carbohydrates then can be further broken down into simple (sugars) and complex (starches). Each of these food fuel groups has a different density, meaning the amount of calories that each of them bring to the table is different.

When you put these food fuels into your body, they must be broken down into useable form. You cheeseburger can exactly power a muscle, but the complex carbohydrate in the bun can be metabolized into glucose that will fire a muscle.

Once the food is digested and broken into useable components, then one of a couple of things happens to it: it is either burned by your body as fuel to make something happen – such as moving a muscle or making your heart beat – or it is stored for use later.

By stored for use later, I mean that those food fuel left-overs are converted into fat and placed in reserve for times when you’re running low on gas. This is an evolutionary defense mechanism of sorts, in that the body is programmed to stock up on fuel just in case you run out of food and need to keep on living. Think of yourself like a bear preparing for hibernation. Bears put away excess calories for the winter when they sleep and live off their fat stores for months.

Now for the typical person running out of food and hibernating doesn’t happen very often. In fact, most Americans live with a surplus of food at their disposal. Whether it’s the huge portions of foods served in many restaurants or the ubiquitous Starbucks coffee stands (whose Caramel-mochiatos have lots of fat and sugar in them), running short of food isn’t usually the problem. Every time we pack away a little extra fat for our next hibernation, the hibernation doesn’t come and we run the risk of just getting fatter and fatter.

To go back to the car analogy, one of the differences between you and your car is that when you car’s fuel tank is full the gas would just spill out onto the ground. When your fuel tank gets full, your body will just turn that excess into fat and carry it around with you.

So the basic premise then appears quiet simple: add up all the calories that you eat during a day, subtract what you burn and look at the result. Over time, if you burn more calories than you take in, then you will lose weight. If you burn less calories than you take in, you’ll gain weight. If you eat approximately what you burn – all other factors staying equal — you’ll stay about the same.

How do these different “food fuel” types come into play?
Unfortunately, the whole thing is just slightly more complicated than what I just described. It’s not just the amount of calories, but the type of food fuels that we eat which dictates what you have to fuel your body.

Going back to the car analogy yet again, gasoline in your car has a specific purpose in that it makes the engine go. Your body is vastly more complicated and those various fuels (fats, proteins and carbohydrates) all do different things when taken on-board.

Proteins, for example, are useful in building muscle, growing hair and skin, and repairing things when they get broken. Fats are good for metabolizing certain types of vitamins and fat is very useful as an energy source for low-intensity activities. Carbohydrates are the primary fuel used to power your muscles, so they are supremely useful for athletes.

Carbohydrates are further divided into two types. Complex carbohydrates – or starches – are found in grains, bread, pasta, rice, and potatoes. These nutrients are easily converted by the body to fuel that can be used by the muscles. But since they need to be broken apart first (they are complex molecules that need to be split up), they take a little more time to get into place in the muscles to be used. Complex carbohydrates are thus an excellent source of energy for longer endurance activities like running long distances. Simple carbohydrates are – as their name implies – easily broken down and rapidly absorbed by the body, so they are good for quick energy bursts.

Because each of the food fuels plays a different role in the body, it is important that you’re eating the right amount of the foods that you need to power your particular activities. For example, a person that runs a lot needs a lot of complex carbohydrate in their diet in order to give them energy in their workouts. Eating these complex carbohydrates doesn’t cause them to gain weight, because they are burning off lots of carbohydrate when they run. On the other hand, a person that is totally sedentary – say someone who lays in bed all day – wouldn’t need all those carbohydrates, because their muscles don’t need all that fuel.

The problem that many runners have – or let me be more expansive and say the problem that most people have – is that they eat too much of foods that they don’t need. In particular they eat too much fat and too much carbohydrate for their needs and that keeps them overweight.

Bottom line: you need to look at what you’re going to be doing on a particular day and take in the foods that will power those activities. On days when you’re going to run 20 miles, you’ll need lots of carbohydrates. On the day after that run, when you’re lying in bed recovering, you would need all that carbohydrate – instead you’ll probably need more protein to help repair the damage you did in that long run.

There’s three pages of stuff for you to think about. We’ll call that the end of part I. In part II, I’m going to tell you how I would suggest actually structuring a diet that makes sense for you as a runner.

Click here to continue to part II.

If you’d like more information on this topic, there are many great books available. Two of my favorites are available at They are Nancy Clark’s Food Guide for Marathon Runners and Nancy Clark’s Sports Nutrition Guidebook.

Coach Joe English, Portland Oregon USA
Running Advice and News



  1. […] Training: Food as fuel; your diet, weight loss and running (part I) […]

  2. […] Training: Food as fuel; your diet, weight loss and running (part I) […]

  3. […] two related issues: first that running does not always lead directly to weight loss and second the role of diet in that equation. The bottom line is that running, even burning lots of calories, can only result in weight loss if […]

  4. If taking the idea of food being fuel than we must really exert as much as we intake or it damages everything, jus like in a car. We end up cloging everything up

  5. Born obese with foot and knee problems, I’ve endured being harassed, ostracized, ridiculed, and discriminated against throughout my life. I fight obesity every day, am a vegetarian, and run to lower my cholesterol. I have completed three 10Ks and am training for a marathon! Finally, I have the confidence to wear split shorts in public, and receive delightful compliments from my sweetheart. OMG! My new running outfit is so thin and comfortable; it feels like I am running naked! : O
    For once in my life I feel pretty! : )
    DW [age 48]

  6. Cheesecake Factory “Pasta with Shrimp” is 2700 calories. At 10 calories per minute burn, that’s 270 minutes of fuel, or enough to run a marathon. Think about that before you chow down.

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