How do trans-fatty acids affect your health?

Trans-fatty acids can be found in some processed vegetable fats used in food manufacturing. They can also occur naturally in some animal products, like butter and meat. Learn more about them and how they can affect your health.

What are trans-fatty acids?

Trans-fatty acids are formed when liquid vegetable oils are processed with hydrogen. This makes the oil solid. These oils are often called "partially hydrogenated". Foods made with partially hydrogenated oil can have a longer shelf life.

Trans-fatty acids are most likely to be found in:

  • vegetable shortening
  • some margarines
  • crackers and biscuits
  • packaged snacks
  • fried foods
  • baked goods.

Low levels of trans-fatty acids are also found naturally in butter, cheese, and meat.

Intake of trans-fatty acids

Food Standards Australia New Zealand (FSANZ) monitoring of trans-fatty acids in the food supply showed that New Zealanders get 0.6% of their daily energy intake (kilojoules) from trans-fatty acids. Most of the trans-fatty acids we eat are from butter, cheese, and meat.

This falls below the World Health Organization (WHO) recommended maximum of 1% of daily energy intake from trans-fatty acids.

Monitoring of trans-fatty acids – Food Standards Australia New Zealand

What can I do to reduce trans fats in my diet?

Trans-fatty acids occur in many of the same foods that are high in saturated fats. Limiting intake of foods containing saturated fat will also reduce your intake of trans fats.

How to eat less saturated fat, sugar, and salt – Ministry of Health

Read more healthy eating and activity guidelines – Ministry of Health

Are trans-fatty acids identified on food labels?

In most cases, trans-fatty acid content doesn't need to be included on a food label.

However, food makers need to provide this information if their product makes a nutrition content claim about:

  • cholesterol
  • saturated, polyunsaturated, monounsaturated fats, or trans-fatty acids, or
  • omega-3, omega-6, or omega-9 fatty acids.

New Zealand food manufacturers can voluntarily choose to label the trans-fatty acid content of their products.

Find out more

Trans-fatty acids – Food Standards Australia New Zealand

Who to contact

If you have questions about trans-fatty acids in food, email

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