How Cooking Affects Nutrition

The process can destroy (or unlock) your food's potential.
temperature knobs on a home stove-top range

Temperature can have a positive or negative effect on the nutritional value of your food.

How Nutrition Changes When Cooking

Here are some of the processes you need to be aware of.

Negative Effects of High-Temperatures

Some foods lose nutritional value when heated to high temperatures.

  • Protein Denaturation

    When certain foods are cooked at high temperatures (meat, eggs, vegetables, etc.), the protein molecules can change their structure. This may cause some amino acids to be destroyed.

  • Vitamin Loss

    Vitamins tend to dissolve in water, especially when heated, so they can be lost through heating processes.

    For instance, when you boil potatoes, vitamins B and C are absorbed into the water.

  • Mineral Loss

    This will be seen when boiling ingredients. If you need to cook your vegetables, consider steaming.

    Green vegetables such as broccoli have been shown to hold more of their nutrients when steamed.

  • Negative Compounds

    High heat may form some undesirable compounds such as carcinogenic substances.

Nutrients That Unlock at High Temperatures

There are also foods that increase in nutrients and benefit from heating. Some of these foods are;

  • Root Vegetables

    Without heating, these vegetables can be hard to digest. Heating them softens their structure so that we can consume them.

    Cooking carrots actually allows for the cell walls to break down, providing more beta-carotene (linked with good eye health and immune function).

  • Tomatoes

    Heating tomatoes actually helps to break the cell wall of the tomato, releasing lycopene (beneficial antioxidant compound).

  • Leafy Greens

    When heated, oxalic acid is reduced. This acid blocks iron absorption and is found in greens like spinach or swiss chard.

Dangers of Unhealthy Cookware

Next time you go to cook a meal, be conscious of your cookware. The wrong kind of pot or pan can rob your food of nutrients—or introduce chemical toxins.

  • Nutrient Leaching

    Leaching is when minerals are absorbed from a solid.

    • Non-stick pots and pans are the worst option in terms of leaching. Try and replace them with safer, more effective alternatives.
    • If you use copper pots and pans be aware that foods in which contain a high level of acidity can increase leaching (e.g. tomatoes).
  • Chemical Exposure

    Stay away from cookware that releases chemicals, to truly consume food in the state that makes it most beneficial.

Click to See Our Sources

"Is Your Cookware Poisoning You?" by Emma Deangela,

"4 Veggies and Fruits That Are Healthier to Eat Cooked Than Raw." ​Ecosalon

"The Why, How and Consequences of Cooking Our Food." EUFIC


Emma Deangela

Emma Deangela is the best selling author of The Alkaline Diet Program and 80/20 Fat Loss. She has helped over tens of thousands of men and women to lose weight and transform their health with sound nutrition advice.