Skipping breakfast is considered an important risk factor in the development of obesity, although the effects are mostly indirect. The researchers of the present study investigated whether a high-protein breakfast satiates hunger, thereby decreasing subsequent food consumption and the chances of obesity. They assessed satiety using functional Magnetic Resonance Imaging (fMRI) to test brain activity after both normal and high-protein breakfasts. The study was performed on overweight teenage girls who frequently skipped their breakfast. This study concluded that, “increased dietary protein at breakfast might be a beneficial strategy to reduce subsequent food consumption in overweight teen girls.”
The prevalence of obesity is increasing in epidemic proportions in the US, affecting approximately 25 million youngsters at present. Many studies done earlier have concluded that the habit of skipping breakfast contributes to the development of obesity. Some studies have shown that levels of hunger-related hormones are consistently elevated in people who skip breakfast. This study was done to assess the activity in different parts of the brain among people who usually skip breakfast and those who do not. In addition, they also evaluated the differences in brain activity upon ingestion of a protein-rich breakfast vs. a normal one. Increased activity in certain regions of the brain indicates whether the person is willing to consume food or not. Based on these observations, the person’s satiety and hunger can be evaluated.
- This study included ten obese, adolescent girls who often skipped their breakfast. All of them were subjected to fMRI scans to assess their neural activity on skipping breakfast.
- Participants were divided into two groups. For seven days, the first group received breakfast rich in proteins and the second group received a normal breakfast. Except for the protein content, both breakfasts were similar in calorie content and taste.
- On each day of the experiment, three hours after breakfast, all participants were given a questionnaire to assess their perceived satiety and appetite. Later, all of them were subjected to fMRI scans to assess activities in different parts of the brain. While observing their brain activity using MRI, they were shown photographs of food items, animals, and some line diagrams.
- Skipping breakfast led to increased activity of those parts of the brain that perceive hunger and lead to food cravings.
- Daily consumption of protein-rich breakfast led to decreased neural activity in those regions of the brains that are associated with hunger and motivation for food consumption.
- The results of neural activity obtained through scans correlated with the hunger levels assessed through the questionnaires.
The appetite of girls is influenced by hormonal fluctuations that occur during the menstrual cycle. In the present study, this fact was not considered, which otherwise could have caused variations in the assessment of neural activity. The sample size, which includes just ten participants, is very small. Further studies involving more participants are necessary for a proper generalization of the findings.
Several studies that were done in the past to investigate the relation between breakfast skipping and obesity, assessed hunger either through a questionnaire or by measuring the levels of hunger/satiety related hormones. This is the first study of its kind where an objective measurement of hunger was performed through fMRI studies. Upon intake of a high-protein breakfast, there is less activity in those parts of the brain that prompt a person to consume more food. This observation points out that a regular high-protein breakfast will help in minimizing food consumption throughout the day, alleviating the risk of obesity.
For More Information:
Neural Responses to Visual Food Stimuli after a Normal vs. Higher Protein Breakfast in Breakfast-Skipping Teens: A Pilot fMRI Study
Obesity, May 2011
By Heather Leidy; Rebecca Lepping
From the University of Kansas Medical Center, Kansas City, Kansas
*FYI Living Lab Reports Are Summaries of the Original Research.