How does the body process the nutrients we eat?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)

Contrary to popular belief, all ingested protein doesn't become muscle and all the fat in your food doesn't get stored on your hips. Everything has the potential to turn into fat if it's not used by your body for energy at the exact time it is absorbed through your intestines. And energy is energy is energy. Here's how the different nutrients are processed:

  • Simple sugars (as in a cola): When sugar, which is quickly absorbed and sent to the liver, meets the liver in the digestion process, the liver tells your body to turn that sugar into a fat if it can't be used immediately for energy.
  • Complex carbohydrates (as in whole-grain foods): They take longer to digest so there's a slower release of the carbohydrates that have been converted in your bowel to sugar to become sugar in your bloodstream, and your digestive system is not stressed as much. Still, if your body can't use this slower sugar when it's released, it gets converted to fat.
  • Protein (as in meat): It gets broken down into small amino acids, which then go to the liver. If the liver can't send them to your muscles (say, if you're not exercising and don't need it for muscle growth or maintenance), then, yep, they get converted to glucose, which then gets converted to fat if you can't use it for energy.
  • Fat (as in funnel cake): It gets broken into smaller particles of fat and gets absorbed as fat. Good fats (like those found in nuts and fish) decrease your body's inflammatory response, and bad fats increase it. That inflammatory response is a contributing factor to obesity. If you're exercising and have used up all readily available carbohydrates (sugar), your muscles can use fat for energy, which is a great way to erode your love handles.
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.