For many years, butter was the “unhealthy” bad boy on your toast but as more people are opting to eat less processed foods, butter’s making a comeback. In 2014, butter made up 54 percent of Kiwis’ overall spending on butter and margarine. Despite the hype, the weight of evidence isn’t backing butter.

We looked at 52 spreads to find out what was in them. We also checked their nutrition information and calculated their health star rating.

All about fat

The main ingredient in butter and most table spreads is fat. Butter is more than 80 percent fat and the table spreads in our survey mostly ranged from 46 to 70 percent.

But not all fats are created equal when it comes to your health. Fats and oils are made up of fatty acids – saturated, trans, monounsaturated, and polyunsaturated. Different oils or fats will have varying levels of these fatty acids.

Saturated fat raises the total cholesterol and levels of “bad” LDL (low-density lipoprotein) cholesterol in your blood. Saturated fats can also promote blood clotting, which can lead to heart attacks or stroke. Saturated fats are found in animal fats, as well as palm and coconut oil.

Trans fat raises total cholesterol and LDLs, and may also decrease your levels of “good” HDL (high-density lipoprotein) cholesterol. Small amounts of trans fats occur naturally in butter but harmful trans fats are formed when liquid oils are hydrogenated to harden them and make them more stable to use. Most table spreads contain less than one percent trans fats – a vast improvement on the eight percent some products contained in our previous surveys.

Polyunsaturated and monounsaturated fats are “good” fats. They help lower LDLs and monounsaturates are thought to raise HDLs. Canola, avocado, olive oils and rice bran oils are high in monounsaturates. Sunflower and soya bean oils are high in polyunsaturates.

Star spreads

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Palmed off

Many table spreads in our survey contained palm oil but you may not know it from reading the ingredients list. There’s no requirement for manufacturers to disclose palm oil – it often hides under “vegetable oil”. Palm and palm kernel oil are high in saturated fat. Their production can also have major environmental impacts.

We asked companies to disclose what vegetable oils are in their products. Some were more open than others.

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Butter v marge

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Report by Belinda Castles.