The US is playing catch up to Australia when it comes to regulating trans fatty acid, but that doesn't mean our food is trans-fat free, some of the country's peak nutritional experts say.

The Obama Administration on Tuesday ordered ordered food companies to phase out artificial trans fats over the next three years, calling them a threat to public health.

Trans fats are more likely to be found in processed foods including pastries, doughnuts and cakes at the cheaper end of the market. Credit:M. Spencer Green

Trans fats are a particularly nasty fat that increases LDL, or 'bad' cholesterol levels and decreases 'good' HDL cholesterol levels, increasing the risk of cardiovascular disease (CVD) and diabetes.

Trans-fatty acids are created by treating vegetable oils with hydrogen, which causes the liquid oil to hold its solid form at room temperature, which helps food products like doughnuts, biscuits and cakes hold their shape and extends their shelf life.