Cereals which contain chocolate chips and nut crisps are often packed with sugar and fat, said food watchdog, the Food Commission.
The worst offender is Quaker's Harvest Crunch with red berries which has six grammes of saturated fat per bowl.
It also has high levels of sugar, but not much fibre.
Toast is better
Other cereals with lots of fat include:
- Waitrose Chocolate and Nut Crisp
- Marks and Spencer's Decadence
- Tesco Choc and Nut Crisp
Food experts say we shouldn't eat these cereals every day.
They say muesli, bran flakes and toast are much better because they contain lots more fibre and much less fat.