Neural responses to visual food stimuli after a normal vs. higher protein breakfast in breakfast-skipping teens: a pilot fMRI study

Abstract

This functional magnetic resonance imaging (fMRI) pilot study identified whether breakfast consumption would alter the neural activity in brain regions associated with food motivation and reward in overweight "breakfast skipping" (BS) adolescent girls and examined whether increased protein at breakfast would lead to additional alterations. Ten girls (Age: 15 ± 1 years; BMI percentile 93 ± 1%; BS 5 ± 1×/week) completed 3 testing days. Following the BS day, the participants were provided with, in randomized order, normal protein (NP; 18 ± 1 g protein) or higher protein (HP; 50 ± 1 g protein) breakfast meals to consume at home for 6 days. On day 7 of each pattern, the participants came to the laboratory to consume their respective breakfast followed by appetite questionnaires and an fMRI brain scan to identify brain activation responses to viewing food vs. nonfood images prior to lunch. Breakfast consumption led to enduring (i.e., 3-h post breakfast) reductions in neural activation in the hippocampus, amygdala, cingulate, and parahippocampus vs. BS. HP led to enduring reductions in insula and middle prefrontal cortex activation vs. NP. Hippocampal, amygdala, cingulate, and insular activations were correlated with appetite and inversely correlated with satiety. In summary, the addition of breakfast led to alterations in brain activation in regions previously associated with food motivation and reward with additional alterations following the higher-protein breakfast. These data suggest that increased dietary protein at breakfast might be a beneficial strategy to reduce reward-driven eating behavior in overweight teen girls. Due to the small sample size, caution is warranted when interpreting these preliminary findings.

Conflict of interest statement

DISCLOSURE

The authors declared no conflict of interest.

Figures

Figure 1

Study design.

Figure 2

Prelunch a priori brain activation following the addition of breakfast; all comparisons food > nonfood (animal). (a) Averaged functional magnetic resonance imaging (fMRI) brain activation contrast map; *greater activation following breakfast skipping vs. normal protein breakfast in the (A) hippocampus, (B) amygdala, (C) subgenual anterior cingulate, and (D) parahippocampus, *Cluster-level statistical threshold adjustment for multiple comparisons; P = 0.01; α = 0.05. (b) Bold effect depicting treatment differences (breakfast skipping vs. normal protein breakfast) in average percent signal change (food vs. nonfood) from the maximum voxel of the activations in a.

Figure 3

Prelunch a priori brain activation following the normal protein (NP) vs. higher protein (HP) breakfast treatments; all comparisons food > nonfood (animal). (a) Averaged functional magnetic resonance imaging (fMRI) brain activation contrast map; *greater activation following the normal protein vs. higher protein breakfast in the (A) insula and (B) middle prefrontal cortex. Cluster-level statistical threshold adjustment for multiple comparisons; P = 0.01; α = 0.05. (b) Bold effect depicting treatment differences (normal protein vs. higher protein breakfast) in average percent signal change (food vs. nonfood) from the maximum voxel of the activations in Figure 3a.