The theory that breakfast is the most important meal of the day - including for dieters - may not be true, research suggests.
A review of studies found that eating breakfast does not appear to help people lose weight and should not necessarily be recommended as a weight-loss strategy.
Previous studies have suggested that eating breakfast revs up the metabolism and can help dieters stop overeating later in the day.
The British Dietetic Association (BDA) says research shows that "people who eat breakfast have more balanced diets than those who skip it, are less likely to be overweight (and) lose weight more successfully if overweight."
But a new review sheds doubt on this idea. It also challenges studies that suggest skipping breakfast can disrupt the body's internal clock and lead to weight gain.
Experts from Monash University in Melbourne, Australia, examined 13 studies related to breakfast and weight in high income countries, including the UK.
The pooled results found a very small difference in weight between those who ate breakfast and those who did not, with those who skipped breakfast on average 0.44kg lighter.
Those who ate breakfast also ate more calories per day - about 260 more on average.
Thus people who skipped breakfast did not compensate by eating more later in the day, the review found.
The researchers also found no significant difference in metabolic rates between breakfast eaters and skippers - suggesting there is no evidence that eating breakfast may help with weight loss due to "efficient" burning of calories earlier in the day.
The authors said the overall quality of the studies was low and more research is needed.
Writing in the British Medical Journal (BMJ), they said: "This study suggests that the addition of breakfast might not be a good strategy for weight loss, regardless of established breakfast habit.
"Caution is needed when recommending breakfast for weight loss in adults, as it could have the opposite effect."
They added: "Further high quality randomised controlled trials are needed to substantiate whether those individuals seeking to lose weight should skip or consume breakfast and the role of breakfast eating in an overall weight management approach."
The study went on: "While breakfast has been advocated as the most important meal of the day in the media since 1917, there is a paucity of evidence to support breakfast consumption as a strategy to achieve weight loss, including in adults with overweight or obesity."
It said eating breakfast regularly could have other important effects, such as improved concentration and attentiveness levels in children.
Dr Frankie Phillips, registered dietitian for the British Dietetic Association, said: "Whilst some studies do show that people who eat breakfast tend to be a healthier weight, there is no clear benefit of starting to eat breakfast just as a tool to lose weight.
"The study shows that simply having breakfast isn't a magic recipe for weight loss for everyone.
"If you do enjoy breakfast, don't stop, but take a look at what you are having.
"Breakfast has the potential to be one of the easiest times of the day to eat a balanced meal, and to meet a number of nutrition targets.
"So a simple breakfast of wholegrain cereal and milk with a glass of unsweetened fruit juice and a cup of tea provides protein, fibre, a raft of vitamins and minerals and plant phytochemicals.
"If you are someone who can't face breakfast at 7am, take it with you and have breakfast at work.
"But plan what you have as it's far better to take breakfast with you than to grab a chocolate muffin and a latte from the nearest coffee shop when you get hungry later."