The research, published in Annals of Nutrition and Metabolism, investigated how different breakfasts affect feelings of fullness and later appetite and food intake by comparing the effects of quick-cook oatmeal, sugared corn flakes and water in a small group of healthy weight and overweight individuals.
According to study findings, consumption of oatmeal (Quaker Oats Quick 1-minute) for breakfast resulted in greater fullness, lower hunger ratings and fewer calories eaten at the next meal compared to a calorie-matched amount of the ready-to-eat sugared corn flakes cereal.
"Our results show that despite eating the same number of calories at breakfast, satiety values were significantly greater after consuming oatmeal compared to sugared corn flakes,” said lead researcher Dr Allan Geliebter from Mount Sinai St. Luke's Hospital. “After three hours, subjects reported the same level of hunger after having a corn flakes breakfast as they did when they consumed only water."
"Interestingly, the results were more pronounced for the participants who were overweight, suggesting that overweight individuals may be more responsive to the satiety effects of the dietary fibre in oatmeal."
The Quaker-backed research analysed data from 36 subjects (18 lean, 18 overweight) who were assigned to three conditions in a randomised sequence on different days. The breakfasts consisted of 350 calories of similar amounts of carbohydrates, fat and liquid from either quick-cook oatmeal or sugared corn flakes, or a control breakfast consisting of 1.5 cups of water.
The team then evaluated participants’ appetite, ratings of hunger and fullness at frequent intervals before and after the breakfast until a lunch test meal 3 hours later. Ratings of hunger and fullness were taken alongside blood samples which were used to measure concentrations of glucose, insulin, glucagon, leptin, and acetaminophen (a proxy for gastric emptying).
The results showed statistically significant higher ratings of fullness, lower ratings of hunger, and 31% fewer calories consumed at lunch after consuming oatmeal compared to sugared corn flakes or water, said Geliebter and colleagues.
This overall satiety effect was found to be even greater among overweight subjects, who consumed 50% fewer calories at lunch after eating oatmeal, they added.
The study authors suggested that the greater satiety effect of oatmeal cereal compared to sugared corn flakes or water might be due to a slower gastric emptying, noting that markers of gastric emptying (acetaminophen) suggested that oatmeal took longer to leave the stomach.
Battling the bulge
Given that the results were more pronounced in overweight subjects, the researchers suggested that a longer-term weight control study testing daily oatmeal for breakfast is warranted.
"Consumers choose oatmeal for its great taste, well-established health benefits and convenience, but scientists are finding that eating oatmeal for breakfast may also be one of the easiest ways to improve satiety after breakfast," commented Dr Marianne O'Shea, director of the Quaker Oats Center of Excellence.
"We are encouraged by the potential for future investigations that could have a positive impact on public health and give people more reasons to enjoy oat-based breakfasts and snacks."
Source: Annals of Nutrition and Metabolism
Published online ahead of print, doi: 10.1159/000365933
“Effects of Oatmeal and Corn Flakes Cereal Breakfasts on Satiety, Gastric Emptying, Glucose, and Appetite-Related Hormones”
Authors: A. Geliebter, et al