Forget counting calories and cutting out carbs. The key to losing weight could be as simple as having two eggs for breakfast.
Scientists have shown that those who start their day with poached, boiled or scrambled eggs can lose up to two-thirds more weight than others.
So the old adverts which urged us to "Go to work on an egg" could have been right after all.
The secret of the egg's success lies in its ability to make us feel full for longer than many other foods.
Researchers from Louisiana State University in the U.S. looked at the eating habits of a group of overweight and obese women.
The women, who were following a low-fat diet, were asked to eat either two eggs a day for breakfast, or have a bagel.
The two meals contained the same number of calories and weighed roughly the same amount.
However, after eight weeks of breakfasting, the slimmers who had eaten eggs had lost the most weight.
As well as shedding 65 per cent more pounds than the bageleaters, they had lost almost twice as many inches from their waistline, the Federation of American Societies for Experimental Biology's annual conference heard yesterday.
The study, which was part-funded by the American Egg Board, also showed that those who had breakfasted on eggs felt as if they had more energy.
Previous work by the same researchers showed that those who ate eggs for breakfast felt fuller for longer than those who had a bagel and cheese.
As a result, they ate less during the rest of the day.
It is not completely clear why eggs are so good at making us feel full but it is thought their high protein content could play a large part.
Researcher Dr Nikhil Dhurandhar, an obesity expert, said:
"Despite equal energy content and weight, an egg breakfast had a greater satiating effect compared to a bagel breakfast, which translated into a lower energy intake at lunch."
"The resulting decrease in energy consumption lasted for at least 24 hours after the egg breakfast.
"These results have potentially significant implications. Eggs are an integral part of breakfast in numerous cultures and the satiating effect of eggs may be useful in reducing energy intake thereby promoting weight management."
In Britain, the Food Standards Agency says that while eggs are a good choice as part of a healthy, balanced diet, it is important to eat as great a variety of foods as possible.
It does not set a limit on the number of eggs we should eat a week for optimum health and says that while eggs do contain cholesterol, saturated fat found in cakes, biscuits and pies is more damaging.
Eggs gained in popularity thanks to the widespread adoption of the highprotein Atkins diet. But sales have also suffered from a series of food scares over the past two decades.
"Go to work on an egg" was used in a 1960s advertising campaign by the Egg Marketing Board.
The phrase was widely believed to have been the idea of author Fay Weldon, although she has since said it was actually written by a junior member of staff at the advertising agency where she was head copywriter at the time.