The Unconventional Role for Gastric Volume in the Response to Bariatric Surgery for Both Weight Loss and Glucose Lowering.

OBJECTIVE: To study the relationship between the amount of surgery-induced gastric volume reduction and long-term weight loss and glucose tolerance. BACKGROUND DATA: Vertical sleeve gastrectomy (VSG) has recently surpassed gastric bypass to become the most popular surgical intervention to induce sustained weight loss. Besides inducing significant weight loss, VSG also improves glucose tolerance. Although no clear correlation has been observed between the size of the residual stomach and sustained weight loss, this begs the question whether less aggressive gastric volume reduction may provide sufficient efficacy when weight loss is not the major goal of the surgical intervention. METHODS: A series of strategies to reduce gastric volume were developed and tested in Long Evans male rats, namely: VSG, Fundal (F)-Resection, Gastric Sleeve Plication (GSP), Fundal-Plication, and Fundal-Constrained. RESULTS: All surgical interventions resulted in a reduction of gastric volume relative to sham, but none of the interventions were as effective as the VSG. Gastric volume was linearly correlated to increased gastric emptying rate as well as increased GLP-1 response. Overall, cumulative food intake was the strongest correlate to weight loss and was logarithmically related to gastric volume. Regression modeling revealed a nonlinear inverse relation between body weight reduction and gastric volume, confirming that VSG is the only effective long-term weight loss strategy among the experimental operations tested. CONCLUSIONS: The data suggest a minimum threshold volume of the residual stomach that is necessary to induce sustained weight loss. Although all gastric volume interventions increased the GLP-1 response, none of the interventions, except VSG, significantly improved glucose tolerance. In conclusion, if weight loss is the primary goal of surgical intervention, significant volume reduction is required, and this most likely requires excising gastric tissue.

Prevalence and Determinants of Engagement with Obesity Care in the United States.

OBJECTIVE: Medical management of obesity can result in significant weight loss and reduce the burden of obesity-related complications. This report employs a new conceptual model to quantify engagement with obesity care and associated determinants in the US adult population. METHODS: Engagement with obesity care was conceptualized as a cascade comprising 5 successive steps: perceiving oneself as overweight, desiring to lose weight, attempting weight loss, seeking care from a health care professional for obesity, and seeking care from a physician specifically. RESULTS: Among adults with obesity, 7.3% did not perceive themselves as overweight, 1.5% perceived themselves as overweight but had no desire to lose weight, 29.9% wanted to lose weight but did not try in the last year, 51.3% tried to lose weight but did not consult a health professional, and 6.4% sought help for weight loss from a health professional but not a physician, implying that 96.4% of the population with obesity had an unmet need for obesity care. CONCLUSIONS: This analysis provides new insight into the most common points along the cascade at which disengagement occurs and can inform efforts to improve uptake of obesity-related health care services.

Obesity Progression Between Young Adulthood and Midlife and Incident Diabetes: A Retrospective Cohort Study of U.S. Adults.

OBJECTIVE: Understanding how changes in weight over the life course shape risk for diabetes is critical for the prevention of diabetes. Using data from the National Health and Nutrition Examination Survey (NHANES), we investigated the association between self-reported weight change from young adulthood to midlife and incident diabetes. RESEARCH DESIGN AND METHODS: We categorized individuals into four weight-change groups: those who remained nonobese (stable nonobese), those who moved from an obese BMI to a nonobese BMI (losing), those who moved from a nonobese BMI to an obese BMI (gaining), and those who remained obese (stable obese). Diabetes status was determined by self-report of a prior diagnosis, and age at diagnosis was used to establish time of diabetes onset. Hazard ratios (HRs) relating weight change to incident diabetes over 10 years of follow-up were calculated using Cox models adjusting for covariates. RESULTS: Those who were obese and lost weight exhibited a significantly lower risk (HR 0.33; 95% CI 0.14, 0.76) of diabetes compared with those with stable obesity. We also observed lower risk among those who were stable nonobese (HR 0.22; 95% CI 0.18, 0.28) and those in the gaining category (HR 0.70; 95% CI 0.57, 0.87). Further, there was evidence of an increased incidence of diabetes among obese individuals who lost weight compared with individuals who were stable nonobese; however, weight loss was rare, and the association was not statistically significant. If those who were obese had become nonobese during the 10-year period, we estimate that 9.1% (95% CI 5.3, 12.8) of observed diabetes cases could have been averted, and if the population had maintained a normal BMI during the period, 64.2% (95% CI 59.4, 68.3) of cases could have been averted. CONCLUSIONS: The findings from this study underscore the importance of population-level approaches to the prevention and treatment of obesity across the life course of individuals.