Eggs are well known to have a 50 per cent higher satiety index than regular breakfast cereals, which is generally believed to be due to the high protein content of the eggs.

But authors of the new study, concluded that the protein content was not the sole factor responsible for the satiating effect of eggs.

Their research examined the impact of egg-breakfasts on perceived cravings over the subsequent 36 hours on 30 overweight and obese women.

For the energy reducing effects of egg breakfasts to be relevant, it was appropriate to test the responses of a group of subjects who may potentially benefit from such a satiating effect.

The women with a body mass index greater than 25, were randomized and the effects of the breakfast (bagel or egg) tested two weeks apart.

The egg breakfast consisted of two eggs scrambled, two slices of toast, and one tablespoon of reduced calorie fruit spread. The bagel breakfast consisted of one bagel, two tablespoons of cream cheese and three ounces of low fat yoghurt.

The breakfasts contained the same number of calories and both weighed in at around 188 grams.

Satiety was measured using the Fullness Questionnaire and the State-Trait Food Cravings Questionnaire.

The volunteers who ate the egg breakfast reported greater levels of satiety and consumed 164 calories less for lunch, and 400 calories less over the next 36 hours.

The researchers reject the proposal that the higher protein content of the egg breakfast (5 grams more than the bagel breakfast) is the sole reason for the increased sensation of satiety, since the fat content of the egg breakfast was also higher.

Calories from fat have been linked to increased feelings of hunger and greater food intake.

The researchers did not describe a potential mechanism for the satiety effect of eggs but said: “Clearly, the satiety impact of various foods is impacted by additional factors beside simple macronutrient composition”.