Innovative Techniques for Evaluating Behavioral Nutrition Interventions

Abstract

Assessing outcomes and the impact from behavioral nutrition interventions has remained challenging because of the lack of methods available beyond traditional nutrition assessment tools and techniques. With the current high global obesity and related chronic disease rates, novel methods to evaluate the impact of behavioral nutrition-based interventions are much needed. The objective of this narrative review is to describe and review the current status of knowledge as it relates to 4 different innovative methods or tools to assess behavioral nutrition interventions. Methods reviewed include 1) the assessment of stress and stress responsiveness to enhance the evaluation of nutrition interventions, 2) eye-tracking technology in nutritional interventions, 3) smartphone biosensors to assess nutrition and health-related outcomes, and 4) skin carotenoid measurements to assess fruit and vegetable intake. Specifically, the novel use of functional magnetic resonance imaging, by characterizing the brain's responsiveness to an intervention, can help researchers develop programs with greater efficacy. Similarly, if eye-tracking technology can enable researchers to get a better sense as to how participants view materials, the materials may be better tailored to create an optimal impact. The latter 2 techniques reviewed, smartphone biosensors and methods to detect skin carotenoids, can provide the research community with portable, effective, nonbiased ways to assess dietary intake and quality and more in the field. The information gained from using these types of methodologies can improve the efficacy and assessment of behavior-based nutrition interventions.

Keywords: biosensors; brain responsiveness; community nutrition interventions; eye-tracking; nutrition assessment; program evaluation; public health; reflective spectroscopy; resonance Raman spectroscopy; smartphone.

FIGURE 1

The Social Ecological Model provides a framework for considering what and how to evaluate the impact of a community-based nutrition intervention. Adapted from reference with permission.

FIGURE 2

Higher chronic stress exposure, as measured by the Wheaton Chronic Stress Questionnaire, and stress-induced cortisol hyporesponsiveness as associated with greater consumption of highly palatable food (e.g., chocolate cake) from a voluntary snack food buffet. Chocolate cake intake data were adjusted for total energy intake from the buffet. Salivary cortisol was collected at home and during a laboratory visit in response to a standard meal challenge and mental stress test. Low and high chronic stress are indicated above the graphs. Salivary cortisol reactivity is indicated within and below the graph by gray (low reactivity) and white (high reactivity) bars. Means in the main panel without a common letter differ, P < 0.05. In the inset, salivary cortisol concentrations during the visit are presented to show low (blue) and high (red) cortisol reactivity. *Different from low reactors, P < 0.05. Adapted from reference with permission.

FIGURE 3

In response to viewing pictures of high-calorie foods, compared with low-calorie foods and nonfood control images, women with more chronic stress and hypocortisolemia showed enhanced activation in brain regions linked to emotionality (e.g., amygdala) and deactivation in executive brain regions (e.g., Brodmann’s area 10). BA10, Brodmann's area 10. Adapted from reference with permission.

FIGURE 4

Heat map showing visual attention aggregated via an eye-tracking camera. Warmer colors (e.g., red) on the heat map represent higher concentrations of visual attention.

FIGURE 5

Schematic diagram (A) and photo (B) of a cradle that interfaces with the back-facing camera of a smartphone that enables the camera to function as an optical spectrometer. (C) Absorption spectra for a series of ELISA assays taken with the system for the detection of peanut allergen Ara h1, which shows increasing absorption over a wide band of wavelengths with increasing Ara h1 concentration. Ara h 1, Arachis hypogaea allergen 1.

FIGURE 6

Pressure-mediated reflection spectrometer (the “Veggie Meter”).

FIGURE 7

(A) Plasma carotenoid concentrations in men and women (n = 29) assessed by HPLC at baseline and at the mid- and endpoints of each phase of the study (phase 1: depletion of carotenoid-rich foods; phase 2: experimental feeding; phase 3: second depletion; phase 4: return to usual diet). (B) RRS intensities at the same 9 time points. Values are means ± SEMs, n = 29. Repeated-measures ANOVA, followed by Tukey contrasts for post hoc comparisons of means, was used to test for changes over phases of the study in plasma total carotenoid concentrations and RRS intensities. Means not sharing a common letter differ, P < 0.05. BL, baseline; RRS, resonance Raman light-scattering spectroscopy. Adapted from reference with permission.