The Food Standards Agency has warned that roasting and frying starchy foods could increase the risk of cancer.
The government body issued a public warning over the risks of acrylamide – a chemical compound that forms in some foods such as potato products, many root vegetables, olives and pizza bases when they are cooked at high temperatures (above 120C).
A new campaign tells people how they can cut their risk, including opting for a gold colour – rather than darker brown – when frying, roasting, baking, grilling or toasting.
Skinny fries and crisps appear to have the highest levels.
Acrylamide forms due to a chemical reaction between certain sugars and an amino acid (asparagine) in the food.
However, boiling, steaming and microwaving appear far less likely to cause the reaction.
The agency advises that people should aim for a golden yellow colour or lighter when frying, roasting, baking or toasting starchy foods.