What Are Processed Foods and Why They Matter for Your Metabolism

kristiehowlett
Aug 25
3 min read

Ultra-processed foods now make up over half the calories Americans eat—and they’re quietly sabotaging your metabolic health. If you’re dealing with fatigue, cravings, inflammation, or stubborn weight gain, your pantry might be part of the problem.

What “Processed” Really Means (and Why It Matters)

“Processed food” is a buzzword tossed around often, but what does it really mean? And more importantly, how is it affecting your energy, hormones, and long-term health?

🔍 Let’s Break It Down

Not all “processing” is bad. Freezing broccoli? Fine. But refining grains, extracting oils, or creating shelf-stable “foods” in a lab? That’s where things go off the rails.

Ultra-processed foods (think protein bars, chips, flavored yogurts, frozen dinners) are engineered for taste and profit, not health. These foods can cause oxidative stress, insulin resistance, gut disruption, and even increase your cancer risk.

Let’s clarify the confusion and uncover why processed foods can be so harmful to your metabolic health—and how you can navigate your grocery store with more confidence.

The Four Types of Processing

We use the NOVA classification system, which places foods into four categories:

Unprocessed or Minimally Processed – Fresh vegetables, frozen berries, eggs, raw nuts, wild fish. These should make up the bulk of your meals.
Processed Culinary Ingredients – Olive oil, sea salt, butter. Useful in small amounts to prepare whole foods.
Processed Foods – Think canned beans, smoked salmon, or hummus made with real ingredients. These can be part of a healthy diet, depending on what’s added.
Ultra-Processed Foods – The worst offenders. These are factory-made creations full of additives, preservatives, synthetic flavors, emulsifiers, seed oils, and refined sugars.

These ultra-processed foods are built for shelf-life, not nourishment, and the body doesn’t recognize them as food.

Why Ultra-Processed Foods Are Harmful

Disrupt blood sugar: Refined grains and added sugars spike glucose and insulin, contributing to insulin resistance, one of the earliest signs of metabolic dysfunction.
Damage the gut: Artificial ingredients and emulsifiers disrupt gut bacteria, promoting inflammation and impairing immunity.
Drive inflammation: From industrial seed oils (like soybean and canola) to trans fats and BPA-lined packaging, these ingredients stir up internal stress that fuels chronic disease.
Lack of fiber: While fiber is not essential, it can be helpful for blood sugar regulation, feeding the microbiome, and promoting satiety. Ultra-processed foods strip it away.

Acellular Nutrients & Gut Health

Here’s something rarely talked about: the nutrients in these “foods” are often acellular, meaning they’re not wrapped in a natural cell wall like whole foods. This makes them more rapidly absorbed—not by you, but by sugar-hungry gut bacteria that can trigger inflammation and metabolic damage.

Even short-term shifts toward these foods can change the microbial makeup of your gut, leading to long-term consequences.

Five Takeaways for Grocery Shopping

Prioritize real food: Buy foods that look like they came from the earth or the ocean, not a lab.
Read labels wisely: If it has more than five ingredients or words you can’t pronounce, skip it.
Ditch inflammatory oils: Avoid seed oils like canola, corn, and soybean. Choose olive oil, avocado oil, or grass-fed butter instead.
Minimize packaged foods: If it’s in a box or bag, check for added sugars, emulsifiers, and hidden seed oils.
Avoid BPA and phthalates: Look for “BPA-free” on cans and avoid plastic marked with a #3 in the recycling symbol.

⚠️ Quick Tip

If your great-grandmother wouldn’t recognize it as food, put it back on the shelf.

Final Thoughts

🥦 The Bottom Line

Whole, real foods—ones that don’t need a label—are your best allies in metabolic recovery and cancer prevention. A quick label check can tell you a lot. If it reads like a science experiment or has more than 5 ingredients you don’t recognize, it’s probably working against you.

You don’t have to be perfect. But the more you fill your plate with whole, nutrient-dense, unprocessed food, the more you support your energy, hormones, immune function, and long-term vitality.

Processed food may be the norm, but that doesn’t mean it should be your normal.