Assessment of Physical Activity and Healthy Eating Behaviors Among US Adults Receiving Bariatric Surgery.

Importance: Bariatric surgery effectively treats severe obesity and metabolic diseases. However, individual outcomes vary depending on sustainable lifestyle change. Little is known about lifestyle patterns after bariatric surgery among the US population. Objective: To compare the level of physical activity and eating behavior among postbariatric surgery patients, individuals eligible for surgery, and those with normal weight. Design, Setting, and Participants: A cross-sectional study using nationally representative survey data from National Health and Nutrition Examination Survey 2015-2018. Respondents included for analysis were age 18 years or older, and categorized by individuals with normal weight, individuals who received bariatric surgery, and individuals clinically eligible for bariatric surgery. Analyses were performed from February to October 2021. Main Outcomes and Measures: Self-reported measures were used to assess physical activity (moderate-to-vigorous physical activity [MVPA], sedentary activity, and whether PA guidelines were met) and eating behaviors (total energy intake and Healthy Eating Index [HEI]-2015 diet quality scores). Results: Of 4659 study participants (mean [SD] age, 46.1 [18.6] years; 2638 [weighted percentage, 58.8%] women; 1114 [weighted percentage, 12.7%] Black, 1570 [weighted percentage, 68.6%] White), 132 (3.7%) reported that they had undergone any bariatric surgery. Median (IQR) time since surgery was 7 (3-10) years. After propensity-score weighting, individuals who underwent bariatric surgery reported more time spent in MVPA than those eligible for surgery (147.9 min/wk vs 97.4 min/wk). Among respondents with normal weight, 45.6% (95% CI, 40.8% to 52.4%) reported meeting PA guidelines, almost 2 times higher than those in the bariatric surgery (23.1%; 95% CI, 13.8% to 32.4%) or in the surgery-eligible group (20.3%; 95% CI, 15.6% to 25.1%). Propensity-score weighted overall HEI was higher for individuals with normal weight (54.4; 95% CI, 53.0 to 55.9) than those who underwent bariatric surgery (50.0; 95% CI, 47.2 to 52.9) or were eligible for the surgery (48.0; 95% CI, 46.0 to 50.0). Across all HEI components, mean scores were similar between the bariatric surgery and surgery-eligible groups. Total energy intake was the lowest among those who underwent bariatric surgery (1746 kcal/d; 95% CI, 1554 to 1937 kcal/d), followed by those with normal weight (1943 kcal/d; 95% CI, 1873 to 2013 kcal/d) and those eligible for bariatric surgery (2040 kcal/d; 1953 to 2128 kcal/d). Conclusions and Relevance: In this cross-sectional study, individuals who underwent bariatric surgery had beneficial lifestyle patterns compared with those eligible for surgery; however, these improvements seemed suboptimal based on the current guidelines. Efforts are needed to incorporate benefits of physical activity and a healthy, balanced diet in postbariatric care.

Social Status and Adolescent Physical Activity: Expanding the Insurance Hypothesis to Incorporate Energy Expenditure.

Low social status (SS) is a determinant of poor health status and is associated with increased disease burden. Obesity affects 20.6% of American adolescents, most of whom are from low-SS families. Contributors to the development of obesity among adolescents include sedentary behavior and low levels of physical activity. Environmental determinants-infrastructure, policy, and social relationships-influence engagement in physical activity and are affected by SS. Significant declines in physical activity have been documented during adolescence, and adolescents of low SS engage in significantly less physical activity per week than those with high SS. This article briefly reviews the literature on the relationship between SS and physical activity in adolescents and introduces a proposed biological mechanism that may explain that relationship. Characterizing the effects that SS can have on physical activity may help tailor clinical interventions and public health campaigns seeking to improve adolescent physical activity and weight management, thus increasing their effectiveness. This may be particularly beneficial for underserved populations.

Mobile Device Accuracy for Step Counting Across Age Groups.

BACKGROUND: Only one in five American meets the physical activity recommendations of the Department of Health and Human Services. The proliferation of wearable devices and smartphones for physical activity tracking has led to an increasing number of interventions designed to facilitate regular physical activity, in particular to address the obesity epidemic, but also for cardiovascular disease patients, cancer survivors, and older adults. However, the inconsistent findings pertaining to the accuracy of wearable devices for step counting needs to be addressed, as well as factors known to affect gait (and thus potentially impact accuracy) such as age, body mass index (BMI), or leading arm. OBJECTIVE: We aim to assess the accuracy of recent mobile devices for counting steps, across three different age groups. METHODS: We recruited 60 participants in three age groups: 18-39 years, 40-64 years, and 65-84 years, who completed two separate 1000 step walks on a treadmill at a self-selected speed between 2 and 3 miles per hour. We tested two smartphones attached on each side of the waist, and five wrist-based devices worn on both wrists (2 devices on one wrist and 3 devices on the other), as well as the Actigraph wGT3X-BT, and swapped sides between each walk. All devices were swapped dominant-to-nondominant side and vice-versa between the two 1000 step walks. The number of steps was recorded with a tally counter. Age, sex, height, weight, and dominant hand were self-reported by each participant. RESULTS: Among the 60 participants, 36 were female (60%) and 54 were right-handed (90%). Median age was 53 years (min=19, max=83), median BMI was 24.1 (min=18.4, max=39.6). There was no significant difference in left- and right-hand step counts by device. Our analyses show that the Fitbit Surge significantly undercounted steps across all age groups. Samsung Gear S2 significantly undercounted steps only for participants among the 40-64 year age group. Finally, the Nexus 6P significantly undercounted steps for the group ranging from 65-84 years. CONCLUSIONS: Our analysis shows that apart from the Fitbit Surge, most of the recent mobile devices we tested do not overcount or undercount steps in the 18-39-year-old age group, however some devices undercount steps in older age groups. This finding suggests that accuracy in step counting may be an issue with some popular wearable devices, and that age may be a factor in undercounting. These results are particularly important for clinical interventions using such devices and other activity trackers, in particular to balance energy requirements with energy expenditure in the context of a weight loss intervention program.