Gregory Pavela

The Inadmissibility of What We Eat in America and NHANES Dietary Data in Nutrition and Obesity Research and the Scientific Formulation of National Dietary Guidelines

The Scientific Report of the 2015 Dietary Guidelines Advisory Committee was primarily informed by memory-based dietary assessment methods (M-BMs) (eg, interviews and surveys). The reliance on M-BMs to inform dietary policy continues despite decades of unequivocal evidence that M-BM data bear little relation to actual energy and nutrient consumption. Data from M-BMs are defended as valid and valuable despite no empirical support and no examination of the foundational assumptions regarding the validity of human memory and retrospective recall in dietary assessment. We assert that uncritical faith in the validity and value of M-BMs has wasted substantial resources and constitutes the greatest impediment to scientific progress in obesity and nutrition research. Herein, we present evidence that M-BMs are fundamentally and fatally flawed owing to well-established scientific facts and analytic truths. First, the assumption that human memory can provide accurate or precise reproductions of past ingestive behavior is indisputably false. Second, M-BMs require participants to submit to protocols that mimic procedures known to induce false recall. Third, the subjective (ie, not publicly accessible) mental phenomena (ie, memories) from which M-BM data are derived cannot be independently observed, quantified, or falsified; as such, these data are pseudoscientific and inadmissible in scientific research. Fourth, the failure to objectively measure physical activity in analyses renders inferences regarding diet-health relationships equivocal. Given the overwhelming evidence in support of our position, we conclude that M-BM data cannot be used to inform national dietary guidelines and that the continued funding of M-BMs constitutes an unscientific and major misuse of research resources.

A narrative review of the associations between six bioactive components in breast milk and infant adiposity

This narrative review examines six important non‐nutritive substances in breast milk, many of which were thought to have little to no biological significance. The overall objective is to provide background on key bioactive factors in breast milk believed to have an effect on infant outcomes (growth and body composition).

Childhood Conditions and Multimorbidity Among Older Adults

OBJECTIVES This research tests whether childhood conditions are associated with trajectories of chronic conditions among older adults. METHODS Using data from the Health and Retirement Study (1992-2008), a series of hierarchical linear models are used to estimate number of chronic conditions at survey midpoint and the rate of increase in chronic conditions across 18 years of data. RESULTS Results suggest that lower childhood socioeconomic status (SES) and poor childhood health are associated with increased number of chronic conditions; however, childhood SES is no longer associated with chronic conditions after adjustment for adult SES and adult health. Poor childhood health continues to be associated with total number of chronic conditions after adjustment for adult SES and health. Rate of change in chronic conditions was not associated with childhood conditions. Results from a multinomial logistic regression model further indicated that the association between childhood conditions and adult multimorbidity increased at higher levels of multimorbidity. DISCUSSION This research adds to the evidence that early life conditions have a lasting influence on adult health, and that their influence may be independent of adult health and SES.

Functional Status and Social Contact Among Older Adults

This article tests whether functional status is associated with likelihood of social contact among older adults. Data come from the Second Longitudinal Study on Aging, a longitudinal nationally representative sample of 9,447 noninstitutionalized individuals aged 70 and over at baseline in 1995. Functional status is measured using an index of activities of daily living (ADL) and instrumental activities of daily living (IADL). Social contact is measured by asking respondents whether they had gotten together socially or talked on the phone with friends/neighbors or family in the past 2 weeks. Greater number of functional limitations is associated with a decreased likelihood of social contact at follow-up via the phone with friends (odd ratio [OR] = 0.94, p < .01) and family (OR = 0.96, p < .01), and a decreased likelihood of getting together with friends (OR = 0.93, p < .01) and family (OR = 0.97, p < .01). Results indicate that functional limitations have a broad impact on self-reported social contact among older adults.

Socioeconomic Status, Risk of Obesity, and the Importance of Albert J. Stunkard

Albert J. Stunkard’s influential career in obesity research spanned over 50 years and included several landmark studies on social factors related to obesity. This review discusses the important contributions Stunkard made to research on the relationship between socioeconomic status socioeconomic status and obesity, extensions of his work, and reflects on Stunkard’s role in the mentoring of succeeding generations of scientists.

Tourism and the treadmill of production: a cross-national analysis

This paper uses Schnaiberg’s theory of the treadmill of production (TOP) to analyze the relationship between foreign direct investment (FDI) and environmental degradation caused by Caribbean tourism. Tourism is estimated to be one of the world’s most rapidly growing economic sectors. While tourism can increase economic activity, problems arise when destinations that draw tourists in through their environmental appeal confront the industry’s ecologically destructive aspects. This paper uses fixed effects panel data methods to examine the relationship between FDI (theorized as the ‘engine’ of the tourism treadmill) and environmental damage caused by tourism. We hypothesize that higher levels of inbound FDI stocks are correlated with increased levels of environmental degradation, as measured by three variables, hotel rooms per square kilometer, primary energy consumption per capita and carbon dioxide emissions per capita. Results from all three models suggest that a relationship exists between the environmental variables and FDI, lending support to the application of TOP theory to the tourism industry.

Social status and energy intake: a randomized controlled experiment

While the inverse association between socioeconomic status (SES) and obesity in high gross domestic product countries is well established using observational data, the extent to which the association is due to a true causal effect of SES and, if so, the mechanisms of this effect remain incompletely known. To assess the influence of social status on obesity via energy intake, we randomized individuals to a higher or lower social status and observed subsequent energy intake.

Body Mass Index and Subjective Social Status: The Coronary Artery Risk Development in Young Adults Study: Subjective Social Status and Obesity

Subjective social status (SSS), or perceived social status, may explain, in part, the relationship between socioeconomic status (SES) and obesity. The objective of this study was to test whether SSS mediates the relationship between two indicators of SES (income and education) and body mass index (BMI).

A Comment on Scherr et al “A Multicomponent, School-Based Intervention, the Shaping Healthy Choices Program, Improves Nutrition-Related Outcomes”

We write in response to the article by Scherr et al1 entitled “A multicomponent, school-based intervention, the Shaping Healthy Choices Program, improves nutrition-related outcomes.” We admire Scherr et al for undertaking such a challenging study on so important a topic, and for wisely using a randomized controlled design, the design that allows for the strongest causal inferences. The article concludes that “The SHCP [Shaping Healthy Choices Program] resulted in improvements in nutrition knowledge, vegetable identification, and a significant decrease in BMI [body mass index] percentiles.”1 Although news of a beneficial program in the domain of childhood obesity would be most welcome, unfortunately this conclusion is derived from an analysis inappropriate for a cluster randomized trial (CRT) and thus cannot substantiate conclusions about the effects of the intervention. We therefore request that the scientific record be corrected with a retraction of, or an erratum to, this article. The following points demonstrate that the conclusions are unsupported by the data and should be revised.

Generalized lambda distribution for flexibly testing differences beyond the mean in the distribution of a dependent variable such as body mass index

Background/Objectives:Conventional statistical methods often test for group differences in a single parameter of a distribution, usually the conditional mean (for example, differences in mean body mass index (BMI; kg m−2) by education category) under specific distributional assumptions. However, parameters other than the mean may of be interest, and the distributional assumptions of conventional statistical methods may be violated in some situations.Subjects/Methods:We describe an application of the generalized lambda distribution (GLD), a flexible distribution that can be used to model continuous outcomes, and simultaneously describe a likelihood ratio test for differences in multiple distribution parameters, including measures of central tendency, dispersion, asymmetry and steepness. We demonstrate the value of our approach by testing for differences in multiple parameters of the BMI distribution by education category using the Health and Retirement Study data set.Results:Our proposed method indicated that at least one parameter of the BMI distribution differed by education category in both the complete data set (N=13 571) (P<0.001) and a randomly resampled data set (N=300 from each category) to assess the method under circumstances of lesser power (P=0.044). Similar method using normal distribution alternative to GLD indicated the significant difference among the complete data set (P<0.001) but not in the smaller randomly resampled data set (P=0.968). Moreover, the proposed method allowed us to specify which parameters of the BMI distribution significantly differed by education category for both the complete and the random subsample, respectively.Conclusions:Our method provides a flexible statistical approach to compare the entire distribution of variables of interest, which can be a supplement to conventional approaches that frequently require unmet assumptions and focus only on a single parameter of distribution.