Alterations in Fecal Short-Chain Fatty Acids after Bariatric Surgery: Relationship with Dietary Intake and Weight Loss.

Bariatric surgery is associated with weight loss attributed to reduced caloric intake, mechanical changes, and alterations in gut hormones. However, some studies have suggested a heightened incidence of colorectal cancer (CRC) has been associated with bariatric surgery, emphasizing the importance of identifying mechanisms of risk. The objective of this study was to determine if bariatric surgery is associated with decreases in fecal short-chain fatty acids (SCFA), a group of bacterial metabolites of fiber. Fecal samples (n = 22) were collected pre- (~6 weeks) and post-bariatric surgery (~4 months) in patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy. SCFA levels were quantified using liquid chromatography/mass spectrometry. Dietary intake was quantified using 24-h dietary recalls. Using an aggregate variable, straight SCFAs significantly decreased by 27% from pre- to post-surgery, specifically acetate, propionate, butyrate, and valerate. Pre-surgery weight was inversely associated with butyrate, with no association remaining post-surgery. Multiple food groups were positively (sugars, milk, and red and orange vegetables) and inversely (animal protein) associated with SCFA levels. Our results suggest a potential mechanism linking dietary intake and SCFA levels with CRC risk post-bariatric surgery with implications for interventions to increase SCFA levels.

Validation of Resting Energy Expenditure Equations in Older Adults with Obesity.

It is unclear which energy expenditure prediction equation should guide weight loss interventions in older adults with obesity. We ascertained the validity of four equations commonly used in practice in a series of weight loss studies of adults aged ≥65 with a body mass index ≥30kg/m2 using indirect calorimetry data. Diagnostic accuracy was defined as <10% discrepancy between predicted and measured resting metabolic rate (RMR). Mean was 73.4 years. RMR using the ReeVue was 1,643 kCal. With 59.0% accuracy, the WHO equation demonstrated the highest accuracy while the Harris-Benedict yielded 53.5% accuracy. The Owens equation demonstrated the least variability (21.5% overprediction, 27.8% underprediction) with 50.7% accuracy. A SECA bioimpedance analyzer noted the second lowest accuracy of 49.6%. Only 43.1% of measurements were within 10% of the gold-standard indirect calorimetry value using the Mifflin equation. All equations demonstrated <60% accuracy suggesting a great need for estimating energy needs.

Incident Impaired Cognitive Function in Sarcopenic Obesity: Data From the National Health and Aging Trends Survey.

Objectives: The prevalence of obesity with sarcopenia is increasing in adults aged ≥65 years. This geriatric syndrome places individuals at risk for synergistic complications that leads to long-term functional decline. We ascertained the relationship between sarcopenic obesity and incident long-term impaired global cognitive function in a representative US population. Design: A longitudinal, secondary data set analysis using the National Health and Aging Trends Survey. Setting: Community-based older adults in the United States. Participants: Participants without baseline impaired cognitive function aged ≥65 years with grip strength and body mass index measures. Methods: Sarcopenia was defined using the Foundation for the National Institutes of Health Sarcopenia Project grip strength cut points (men <35.5 kg; women <20 kg), and obesity was defined using standard body mass index (BMI) categories. Impaired global cognition was identified as impairment in the Alzheimer's Disease-8 score or immediate/delayed recall, orientation, clock-draw test, date/person recall. Proportional hazard models ascertained the risk of impaired cognitive function over 8 years (referent = neither obesity or sarcopenia). Results: Of the 5822 participants (55.7% women), median age category was 75 to 80, and mean grip strength and BMI were 26.4 kg and 27.5 kg/m2, respectively. Baseline prevalence of sarcopenic obesity was 12.9%, with an observed subset of 21.2% participants having impaired cognitive function at follow-up. Compared with those without sarcopenia or obesity, the risk of impaired cognitive function was no different in obesity alone [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82-1.16]), but was significantly higher in sarcopenia (HR 1.60; 95% CI 1.42-1.80) and sarcopenic obesity (HR 1.20; 95% CI 1.03-1.40). There was no significant interaction term between sarcopenia and obesity. Conclusions: Both sarcopenia and sarcopenic obesity are associated with an increased long-term risk of impaired cognitive function in older adults.

Impact of Diet and Exercise on Weight and Cognition in Older Adults: A Rapid Review.

OBJECTIVE: To determine where the current literature stands in regard to diet/exercise interventions on cognition in overweight or obese individuals. DATA SOURCE: A rapid review was conducted of English-language studies published in Medline from January 1965 to January 2020. STUDY INCLUSION AND EXCLUSION CRITERIA: Included studies were intervention studies lasting ≥12 weeks, with participants aged ≥65 years, with a body mass index ≥25 kg/m2. DATA EXTRACTION: Data extracted included study population, duration, intervention design, outcomes, and results. DATA SYNTHESIS: Outcomes were qualitatively measured due to paucity of RTC. RESULTS: 1845 citations were identified, 31 full-text articles were reviewed, and 5 studies were included. Studies had usual care control groups and combined exercise/diet intervention groups with 31-3,526 participants randomized to each arm. Mean age of participants was 69.2-83.4 years. Studies reporting on cognitive changes showed marginally significant positive changes in cognition, and those that reported BMI indicated potential improvements in cognition. CONCLUSIONS: The number of interventions assessing the combined effects of both diet and exercise is low. Future studies should evaluate the impact of combined effects to ascertain whether cognitive decline may be reversed in older adults with a BMI ≥25 kg/m2.

Feasibility and acceptability of a technology-based, rural weight management intervention in older adults with obesity.

BACKGROUND: Older adults with obesity residing in rural areas have reduced access to weight management programs. We determined the feasibility, acceptability and preliminary outcomes of an integrated technology-based health promotion intervention in rural-living, older adults using remote monitoring and synchronous video-based technology. METHODS: A 6-month, non-randomized, non-blinded, single-arm study was conducted from October 2018 to May 2020 at a community-based aging center of adults aged ≥65 years with a body mass index (BMI) ≥30 kg/m2. Weekly dietitian visits focusing on behavior therapy and caloric restriction and twice-weekly physical therapist-led group strength, flexibility and balance training classes were delivered using video-conferencing to participants in their homes. Participants used a Fitbit Alta HR for remote monitoring with data feedback provided by the interventionists. An aerobic activity prescription was provided and monitored. RESULTS: Mean age was 72.9±3.9 years (82% female). Baseline anthropometric measures of weight, BMI, and waist circumference were 97.8±16.3 kg, 36.5±5.2 kg/m2, and 115.5±13.0 cm, respectively. A total of 142 participants were screened (n=27 ineligible), and 53 consented. There were nine dropouts (17%). Overall satisfaction with the trial (4.7+ 0.6, scale: 1 (low) to 5 (high)) and with Fitbit (4.2+ 0.9) were high. Fitbit was worn an average of 81.7±19.3% of intervention days. In completers, mean weight loss was 4.6±3.5 kg or 4.7±3.5% (p< 0.001). Physical function measures of 30-s sit-to-stand repetitions increased from 13.5±5.7 to 16.7±5.9 (p< 0.001), 6-min walk improved by 42.0±77.3 m (p=0.005) but no differences were observed in gait speed or grip strength. Subjective measures of late-life function improved (3.4±4.7 points, p< 0.001). CONCLUSIONS: A technology-based obesity intervention is feasible and acceptable to older adults with obesity and may lead to weight loss and improved physical function. CLINICAL TRIAL REGISTRATION: Registered on Clinicaltrials.gov # NCT03104205 . Registered on April 7, 2017. First participant enrolled on October 1st, 2018.

Addressing Obesity to Promote Healthy Aging.

The population worldwide is aging and prevalence of obesity in this population is increasing. The range of consequences that effect these at-risk patients include increased risk of falls, fractures, reduced quality of life, and cognitive decline. This article describes the epidemiology of obesity, risks and benefits of weight loss, and importance of treating obesity to help promote healthy aging. Health care professionals should encourage older adults with obesity to implement healthy lifestyle behaviors including exercise and diet routine. Treating obesity in older adults mitigates the significant public health crisis, and reduces health care utilization and risk of long-term adverse events.