The Fire Analogy

This is a popular analogy within the diet space and I reference it often because I think it's a great way for people to understand how fuel works in the body.

What fuel do you want to run your body on?

Let’s talk about how the human body uses different types of fuels. I’ll use an analogy of a fire to explain this.

There are essentially 3 sources of fuel for the human body; carbohydrates ( sugar/glucose) , fat and ketones ( fatty acids/lipids/ ketones are a by-product of fat break down). Protein could arguably be in here, however, we don't want to be using protein for energy.

Fire 1:

This fire is made with kindling, twigs and paper scraps. It’s fairly easy to keep throwing stuff on your fire to keep it from burning out, but it's tedious. Kindling burns fast and quick! This fire is hard work because you constantly have to tend to it, and constantly have to replenish the kindling to keep it stoked.

Carbohydrates are the kindling fire. They are your "fast fuels." To keep your engine running, you need to continuously feed it. Carbohydrates break down as glucose in your body, into your blood stream quickly, as your cells swiftly take it up. A fast fuel is just that… FAST! As quickly as it goes in, it burns up fast, and can leave you with low energy, the need for more food and that well-known HANGRY feeling shortly after. The only way to keep this fire going is to quickly throw more kindle on the fire (aka eat more). Leaving people stuck in a paradigm of having to eat every 2-3 hours and the ever so popular blood sugar rollercoaster, where you need to quickly grab a sugary snack to keep your energy steady. Most folks today are solely "sugar burners." Often these folks have unmanageable hunger, cravings, and highs and low with their energy through out the day.

Now, fast fuel isn’t always a bad thing. Heavy weight lifting sessions or elite level athletes may benefit from fueling with carbohydrates. Or, from an evolutionary perspective, in order to avoid getting eaten or killing your food you would need a quick bout of energy fast, so tapping into glucose for fuel was a must. We just don't want to be running our bodies on this fuel source solely, to the point where you can use other fuel sources.

Fire 2:

This fire is made up with strong, thick, sturdy logs. These bad boys will burn for a while and take some time to break down. You don’t have to worry about endlessly scavenging for more kindling to throw on. These logs burn long and slow, providing endless, stable fire for hours. You don’t need to engage in the busy work to keep it going, you just throw on a log and sit back and enjoy.

Fats, Ketones, and Protein are the log fire. They are your "slow fuels." Fat and ketones burn long and slow, and are a reliable source of fuel for our bodies. They provide endless, predictable energy the entire day. We also have ample storage of these on our bodies to keep us going even longer. Even the leanest person has thousands of calories worth of stored fat on their bodies. While glucose only has limited stores. Hunger is long gone with these. When your fire is burning effortlessly, and you feel well-fed, satiated and nourished, have level energy through out the day, and your food decisions are much more thoughtful rather than a call to HANGRY. All is calmer, your hunger is quiet. I even add protein to this, although we don't really derive energy from protein, it's kind of a last resort for our body and protein has a lot of other important processes to aid in the body, so breaking it down as energy is not preferred, but, it does offer satiety ( staying well-fed for hours) so it's a great contributor to this fire.

This doesn’t mean that carbohydrates are a “bad” fuel source, it just means they are not the best for a human body to run on all the time. We want our bodies to have metabolic flexibility, the ability to effortlessly transition from one fuel source to another, depending on the need.

Metabolic Flexibility is the basis of what I teach.

Have questions/comments? Drop them below.

Thanks for reading!