Why Fat and Refined Carbs Don’t Mix – The Cheeseburger Example

Why Fat and Refined Carbs Don’t Mix – The Cheeseburger Example

Video | Calories | Insulin | Fat and Refined Carbs | Takeaway

Three nutrients provide most of the calories that we eat. In this post, I reveal the two that, when eaten together, turn your body into a fat-making factory.

Why Fat and Refined Carbs Don’t Mix – Summary

  • Of the three primary calorie-containing nutrients, carbs are the easiest energy source. 
  • Dietary fat takes longer to digest than refined carbs but provides more long-lasting energy than carbohydrates. 
  • Refined carbs spike insulin, which shuttles energy into fat cells.
  • When you eat refined carbs and fat together, you consume more energy than your body needs, leading to increased fat storage. 

Why Fat and Refined Carbs Don’t Mix [Video]

In this video, you’ll learn…

  • Why a burger on a bun is a bad combination
  • How insulin stores fat
  • Which carbs are OK to mix with fat

How Your Body Uses Calories for Energy

Calories from the foods you eat are turned into energy by your body. There are only three nutrients that provide calories. They are carbohydrates, fats, and proteins. 

Three Nutrients that Provide Calories


Proteins are used for building and repairing tissues. Your body rarely burns them to make energy because that would be wasteful. It would be like using your kitchen chair as wood in your fireplace. The chair, like the protein, has another purpose, so you don’t want to waste it. 

Therefore, only carbs and fats are readily used by your body as energy. 


Carbs, especially refined carbs, are a super easy energy source, kind of like throwing twigs on a fire. They burn fast but don’t last very long. 


Fats are full of energy, but your body must work hard to use them, so they are like the nice big logs in your fire. It takes longer to get them burning, but you get more energy from them.

Insulin – The Fat-Storing Hormone

Your body likes easy, so when you eat a refined carbs, like a piece of bread, your body quickly breaks it down into glucose (the energy molecule) and feeds it to your cells. This feeding process is accomplished thanks to a hormone called insulin

Insulin is what pours fuel into your cells. If your cells are already fueled up to the point where they don’t need energy, then insulin feeds the glucose to your fat cells, which is why you often hear me refer to insulin as your fat-storing hormone.

Digesting Fat

Dietary fat like we might get from meat and cheese is the other nutrient that can be used as energy, but the digestive process is much more labored. 

Your digestive tract must break it down into little fat globs, that then go into your lymphatic system before slowly making their way into your bloodstream. 

Eating Fat by Itself

If you eat fat by itself (and you don’t overeat), your body has time to use most of that slowly processed energy. Also, eating fat by itself does not spike the fat-storing hormone, insulin. 

Why Fat and Refined Carbs Don’t Mix

When you eat refined carbs and fat together, you consume a lot of energy and stimulate the secretion of insulin. We know from research out of MIT that if insulin is present, not only does glucose get shuttled into your fat cells, but also fatty acids. 

why fat and refined carbs don't mix

This explains why a burger on a bun is fattening. The meal is a mixture of refined carbs and fat.  When you take a bite and swallow, your digestive tract goes to work. The carbs, fats, and protein from the meal get broken down into their building blocks (glucose, fatty acids, and amino acids, respectively). 

The amino acids get shuttled away to be used for building and repair, while the glucose and fatty acids get processed for use as energy. 

Remember that the refined bun is a quick and easy energy source that spikes insulin. Your digestive system gets those nutrients processed in the blink of an eye, flooding your cells with energy. Then, along comes the slower digested fatty acids. However, your body’s energy needs have already been met. So, the insulin that is now present in your system shuttles those fatty acids into your fat cells. 

The Takeaway 

A burger on a bun is an excellent fat-making meal. If you are stuck at a fast-food restaurant with no good choices, you’ll feel better when you leave if you throw away the bun and only eat the meat and cheese. 

One last tip: not all carbs are created equal. Refined carbs are much different than the complex carbs found in foods like vegetables. High-quality carbs contain fiber and nutrients that slow the breakdown and absorption of glucose into the blood. This slow digestion dampens the rise of insulin, making fat storage less likely. 

Therefore, the moral of the story, have a salad with good healthy fats like nuts, seeds, avocados, or meat, instead of a sandwich, and you’ll be pleased with your results on the scale. 

Thank you for reading and have a wonderful week!

About the Author

Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.

One thought on “Why Fat and Refined Carbs Don’t Mix – The Cheeseburger Example

  1. Thanks for all your knowledge and expertise. I’m currently following Keto and I’m reluctant to eat a large salad with avocado and nuts with a dressing. I haven’t had a salad in 8 months. I have lost over 42 lbs.

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