Biological normalcy and body fat: Obesity prevalence, fat stigma, and allostatic load among late adolescents and young adults

Macroscopic differences in adult human femora are linked to body mass index

Bone functional adaptation is routinely invoked to interpret skeletal morphology despite ongoing debate regarding the limits of the bone response to mechanical stimuli. The wide variation in human body mass presents an opportunity to explore the relationship between mechanical load and skeletal response in weight-bearing elements. Here, we examine variation in femoral macroscopic morphology as a function of body mass index (BMI), which is used as a metric of load history. A sample of 80 femora (40 female; 40 male) from recent modern humans was selected from the Texas State University Donated Skeletal Collection. Femora were imaged using x-ray computed tomography (voxel size ~0.5 mm), and segmented to produce surface models. Landmark-based geometric morphometric analyses based on the Coherent Point Drift algorithm were conducted to quantify shape. Principal components analyses were used to summarize shape variation, and component scores were regressed on BMI. Within the male sample, increased BMI was associated with a mediolaterally expanded femoral shaft, as well as increased neck-shaft angle and decreased femoral neck anteversion angle. No statistically significant relationships between shape and BMI were found in the female sample. While mechanical stimulus has traditionally been applied to changes in long bong diaphyseal shape it appears that bone functional adaptation may also result in fundamental changes in the shape of skeletal elements.

The Role of Racism in Childhood Obesity

PURPOSE OF REVIEW

Obesity rates continue to rise among children and have shown persistent racial disparities. Racism plays a potentially essential and actionable role in these disparities. This report reviews some mechanisms through which racism may shape childhood obesity.

RECENT FINDINGS

From the youngest ages, disparities in childhood obesity prevalence are already present. Racism may shape intergenerational and prenatal factors that affect obesity and various stressors and environments where children grow up. The relationships between clinicians and patients may also be shaped by everyday racism and legacies of past racism, which may affect obesity prevalence and treatment efficacy. Comprehensive data on the extent to which racism shapes childhood obesity is limited. However, compelling evidence suggests many ways through which racism ultimately does affect childhood obesity. Interventions to address racism at multiple points where it shapes childhood obesity, including intergenerational and prenatal mechanisms, may help to close disparities.

Associations between adverse childhood experiences and history of weight cycling

Background

Adverse childhood experiences (ACEs) predict obesity onset; however, the relationship between ACEs and history of weight cycling has not been adequately explored. This gap is problematic given the difficulty in weight loss maintenance and the impact of ACEs on obesity development, chronicity, and associated weight stigma. The objective of this study was to examine associations between self-reported history of ACEs and weight cycling in a sample of weight loss treatment-seeking adults with overweight/obesity.

Methods

The number of participants in the analyzed sample was 78, mostly white educated adult women (80% female, 81% Caucasian, 75% ≥ bachelor's degree) with excess adiposity enrolled in the Cognitive and Self-regulatory Mechanisms of Obesity Study. ACEs were measured at baseline using the ACEs Scale. History of weight cycling was measured using the Weight and Lifestyle Inventory that documented weight loss(es) of 10 or more pounds.

Results

Higher ACE scores were associated with a greater likelihood of reporting a history of weight cycling. Participants with four or more ACEs had 8 times higher odds (OR = 8.301, 95% CI = 2.271-54.209, p = 0.027) of reporting weight cycling compared with participants with no ACEs. The association of weight cycling for those who endorsed one to three ACEs was not significant (OR = 2.3, 95% CI = 0.771-6.857, p = 0.135) in this sample.

Conclusions

The role of ACEs in health may be related to associations with weight cycling. Results indicated that those who reported four or more ACEs had significantly higher odds of reporting weight cycling compared with those with no ACEs. Further research is needed to further explore how ACEs predict the likelihood of weight cycling, which may be prognostic for sustained weight loss treatment response and weight stigma impacts.