Ounce for ounce, fat has more calories than any other nutrient, so it has been long shunned by dieters. But we just need to know which fats to eat.

Try to eat sources of unsaturated fat, which don’t raise cholesterol – such as oily fish, avocados and nuts – and keep portions small.

While low-carb diets will remain popular this year, it’s predicted that consumers will be welcoming back fat with open arms.

Unlike the Atkins diet, which encouraged followers to increase foods such as cheese and butter, this is all about choosing the right sort of fat.

So you are looking at plenty of oils, avocados, eggs, and so-called fatty fish such as salmon and mackerel. And carbs are also encouraged.

Make sure you stock up on seeds and nuts too, as most registered dieticians named these as the superfood that will reign supreme in 2015.

Banishing high-cal ingredients, such as cheese and nuts, seems a good idea for dieters. But fat takes longer to digest than protein and carbs, so it keeps you full longer.

It also adds flavor, which ups satisfaction. Sprinkle nuts or seeds over your salad or spread pesto on your sandwich. Besides whittling your waistline, you’ll also increase your nutrient intake.

Research has found that just three grams of monounsaturated fat – the amount in less than a teaspoon of olive oil – helps the body absorb more cancer-fighting lycopene, lutein, and beta-carotene.