Having a hearty portion of instant oatmeal for breakfast enhances satiety and feelings of fullness, thereby helping you eat less at lunch, new research has found.

A bowl of instant oatmeal helps curb food intake at lunch better than a leading oat-based, cold cereal -- even when each bowl provided the same number of calories, the findings showed.

The researchers found that a 250-calorie instant oatmeal serving (with an additional 113 calories of skim milk) enhanced satiety and feelings of fullness, reduced the desire to eat and led to lower caloric intake at lunch, compared to a 250-calorie serving of cold, oat-based cereal, also served with an additional 113 calories of skim milk.

"The satiety benefits of instant oatmeal alone were important findings," said lead author Candida Rebello from Louisiana State University in the US.

"When we took it a step further and evaluated the intake four hours post-breakfast, we found that after consuming instant oatmeal, the participants chose to eat significantly less at lunch compared to those who ate the oat-based, cold cereal," Rebello noted.

After an analysis of the types of fibre in each cereal, the researchers suspected that the higher level of the polysaccharides beta-glucan in the instant oatmeal contributed to its satiating effect over the oat-based, cold cereal.

The processing of the cold cereal might lead to changes in the oat fibre that reduced its ability to enhance satiety, the researchers noted.

Researchers presented the participants with a lunch meal of their choice - turkey, ham, roast beef or vegetable patty sandwiches and a calorie-free or calorie-containing beverage, alongside potato crisps and cookies.

The lunches offered ranged from 2,600 to 2,800 calories and participants were told to "eat to satisfaction".

The researchers found that total calorie intake was significantly lower following consumption of instant oatmeal compared to the cold cereal, as were fat and protein intake.

The findings were reported in the Journal of the American College of Nutrition.